Self-diagnosing device for electrically connecting two or more conductors

Abstract

The utility model relates to devices for the timely detection of faults and the prevention of fires, and more particularly to self-diagnosing devices for electrically connecting two or more conductors. The present device for electrically connecting two or more conductors comprises a metallic current-conducting part, an insulating part, and at least two fasteners for conductors electrically connected to the current-conducting part. The electrical connector device further comprises at least one heat-sensitive element capable of undergoing an irreversible change in its external appearance when heated above a corresponding threshold temperature. The utility model provides for increased fire and electrical safety during the use of electrical equipment by providing an electrical connection between two or more conductors that is self-diagnosing by virtue of being capable of irreversibly indicating that at least one temperature threshold has been exceeded.

Description

[0001] A device for electrically connecting two or more conductors with a self-diagnostic function

[0002] The field of technology to which the claimed utility model relates

[0003] The utility model relates to devices for the timely detection of defects and the prevention of fires, namely to devices for the electrical connection of two or more conductors with a self-diagnostic function, by providing the possibility of irreversible visual recording of the fact of heating of the contact connection above at least one threshold temperature.

[0004] State of the art

[0005] Thermal monitoring of contact connections is an important task during electrical equipment operation. Early detection of contact connection defects helps prevent emergency situations that could lead to equipment damage, fires, and conflagrations. Excessive heating of electrical connections is most often associated with an increase in contact resistance, which can occur during operation due to various factors:

[0006] • reduction of the contact area of ​​conductors;

[0007] • oxidation of contact surfaces or formation of carbon deposits on them;

[0008] • galvanic incompatibility of metals of the connected conductors;

[0009] • insufficient applied compressive force during installation of the connection;

[0010] • weakening of pressure during operation;

[0011] • destruction of the surface of conductors due to aggressive exposure to chemicals or electrochemical action;

[0012] • mechanical impact followed by loosening of the contact connection and / or partial removal of the wire from the terminal under the influence of the applied force.

[0013] Electrical contacts between current-carrying parts can be connected using both permanent methods, such as welding, crimping, and soldering, and disassemblable methods, which allow the contact connection to be disassembled and reassembled. When selecting and installing contact connections, it is necessary to refer to technical requirements and standards (GOST 10434-82 "Electrical Contact Connections. Classification, General Technical Requirements", GOST R 50571.5.52-2011, GOST 22483-2012). Methods for inspecting and testing contacts and contact connections of electrical equipment and devices are also regulated by regulatory documents, in particular, GOST 17441-84 "Electrical Contact Connections. Acceptance Rules and Test Methods".

[0014] Detachable contact connections are provided by electrical connectors of various types, such as sockets, cable clamps, terminal blocks, connecting buses, branch clamps and many other types.

[0015] According to GOST 31195.1 “Connecting devices for low-voltage circuits for household and similar purposes”, 2013, a connecting device is a device for the electrical connection of two or more conductors containing one or more terminals and, if necessary, insulation and / or auxiliary elements.

[0016] One example of an electrical connection device (ECD) is a terminal block. The main components of a terminal block include contact elements (the metal conductive part), a locking mechanism (the parts for securing the conductors), and an insulating part. The contact elements are metal clamps or clips that provide the electrical connection between the wires and the contacts of the electrical device. The locking mechanism is typically a clamp, screw, or spring mechanism and serves to securely fasten the wire in the terminal and prevent it from loosening or disconnecting. The insulating part can be a cover for the ECD elements, a housing, a base, or may also contain mounting hardware, such as for DIN rail mounting.

[0017] RU 180661 U1, published June 20, 2018, describes a terminal block comprising a dielectric base made of glass-filled polyamide, with screw terminals rigidly mounted in grooves. These terminals are made in the form of square-section sleeves with axial holes for connecting conductors. The conductors are clamped with bolts. The screw terminals are separated by insulating bridges, which are taller than the sleeves. A protective strip made of insulating material is attached to the insulating bridges.

[0018] There are many other types of UES, which, however, are united by common requirements: reliability of the contact connection; dielectric properties of the insulating part (if any); ease of installation in electrical installations; non-flammability; compactness, etc.

[0019] According to the type of fastening of conductors, it is necessary to distinguish between screw-type terminals, in which the wires are fastened with a screw or clamp (screw-type terminal blocks, neutral and grounding buses), and spring-type terminals (Wag o type terminals), in which the wires are installed by pressing on a spring mechanism.

[0020] By design, UES can be single-contact, intended for connecting one wire to another, or multi-contact, which allow connecting several wires to one device or connecting several devices to each other.

[0021] The use of a UES ensures a convenient and reliable contact connection, but it does not completely eliminate its deterioration during operation. To prevent fires due to defective electrical connections between two or more conductors during operation, it is advisable to regularly monitor their thermal characteristics.

[0022] Regular thermal diagnostics of electrical connections can be carried out using a thermal imager or by using thermal indicator devices.

[0023] Thermal imaging inspection has a number of limitations and does not allow for effective thermal inspection of electrical equipment for the following reasons. Using a thermal imager to assess the condition of electrical equipment and contact connections, including electrical connections between two or more conductors made using a resistive electrical system, is complicated by the difficulty of accessing the conductor contact points for inspection. Furthermore, using a thermal imager requires inspecting equipment under load, as the maximum heating temperatures of electrical connections occur at maximum load currents. Since a thermal imager can only detect electrical equipment heating during inspection, the reliability of contact defect detection is significantly reduced.

[0024] A more effective method for thermal monitoring of electrical connections between two or more conductors is thermal indicator testing. This method relies on the use of irreversible thermal indicators, which are either independent compounds (varnishes and paints) or devices that attach to the monitored components and register when a threshold temperature is exceeded by changing their appearance. While the use of thermal indicator varnishes or paints allows for the application of a temperature-sensitive coating to a surface of any shape and size, it also has a number of fundamental limitations that limit their use. These limitations include:

[0025] - impossibility of specifying the threshold temperature;

[0026] - paint runs off when the threshold temperature is exceeded;

[0027] - it is impossible to determine the temperature with high accuracy, since the paint is applied to the surface in an uneven layer;

[0028] - low adhesion;

[0029] - difficulty in applying paint to surfaces made of non-adhesive materials;

[0030] - dependence of the paint response temperature on the chemical composition of the surface coating.

[0031] Source W02023060325A1, April 20, 2023, discloses an electrical contact connection with a temperature indicator made of a shape-memory alloy and capable of positioning and contacting the contact connection elements. This solution does not disclose the resistivity sensor, but rather the contact connection assembly itself. Using an intermetallic temperature indicator reduces the speed and accuracy of detecting threshold temperature exceedances, as prolonged exposure to temperatures above the threshold is required for the temperature indicator to change shape upon heating.

[0032] For thermal monitoring of contact connections, heat-indicating stickers are widely used. These stickers use a hot-melt compound applied uniformly in a thin layer to a base at the factory, ensuring good adhesion to the surface being monitored. Furthermore, the heat-indicating layer can be coated with a polymer film, which protects it from mechanical or chemical impacts and prevents it from flowing off when melted after activation. An example is the heat-indicating sticker (RU 221997, 06.07.2023), which includes an adhesive layer, a flexible base, and a heat-sensitive material covered with a protective film.

[0033] The presented source utilizes irreversible temperature-sensitive materials that change appearance after exceeding a predetermined temperature and maintain their appearance after cooling. In addition to irreversible materials, reversible compounds are also used in the manufacture of temperature indicators, which change appearance only when heated and return to their original state upon cooling. However, to monitor the condition of contact connections, it is necessary to use irreversible indicators that can detect whether the threshold temperature has been reached at any point in operation, not just during inspection, since the contact connection temperature depends on the load current, which varies over time. The need to use irreversible temperature indicators for electrical equipment diagnostics is discussed, in particular, in the work of M. Yu. Lvov and A. V. Lesiv, "Thermal Indicator Monitoring of Contacts and Contact Connections of Electrical Equipment and Power Lines." M.: NTF "Energoprogress", "Energetik", 2023. P. 62.

[0034] Another important characteristic of temperature indicators is the number of monitored threshold temperatures. Single-temperature temperature indicators record the exceeding of a specific set temperature. This temperature could be, for example, the maximum permissible temperature of the monitored element. Such single-temperature temperature indicator stickers allow personnel to be promptly informed of an emergency or pre-emergency situation, but they do not allow determining the extent or dynamics of the defect. Irreversible multi-temperature temperature indicator stickers detect not only the exceeding of a set temperature but also the numerical value of the maximum surface temperature reached by the monitored element during operation.This allows us to track the dynamics of defect development, provide the ability to compare the heating temperatures of identical parts (assemblies) of equipment, determine the excess temperature, the defect coefficient and their maximum values.

[0035] The prior art includes the use of flexible stickers with color-coded thermal indicators installed near the contacts used to secure electrical components in electrical installations (RU 74211, January 10, 2007). This solution improves the operational reliability of electrical installations by providing simple means for continuous visual monitoring of the condition of bolted and plug-in contact connections of components without removing the load. A combination of reversible and non-reversible color-coded thermal indicators is used as heating indicators. The patent does not disclose the specific component of the electrical equipment on which the thermal indicator sticker is located. In the case of UES, the thermal indicator stickers are placed on an already assembled contact connection, which, due to their small size, is inconvenient and sometimes impossible. This type of installation often cannot ensure a tight fit between the temperature-sensitive element and the electrical equipment surface.This will reduce the accuracy, speed, and reliability of temperature-indicating monitoring. Although temperature-indicating stickers can come in various sizes and shapes, their installation on commercially available UES is difficult or impossible.

[0036] Existing UES are not designed to accommodate temperature-indicating stickers, as they lack suitable and sufficient space for mounting them. To ensure the most compact arrangement of electrical connections, UES manufacturers strive to minimize their size, eliminating the possibility of installing additional temperature monitoring devices near the electrical connection. Furthermore, with distance from the heating point, that is, the contact connection, the temperature drops significantly due to heat dissipation.

[0037] Placing a thermal indicator sticker on a wire outside the UES will be aimed at monitoring the thermal state of the wire, and not the contact connection.

[0038] Thus, despite the wide range of UES, as well as methods for temperature control of electrical connections, in particular, using temperature indicators that differ both in their mechanism of action and in their design, there is a need for UES with the ability to irreversibly record the fact of exceeding the threshold temperature for the timely detection of defects in contact connections, in which at least one TE will be applied to the UES in factory conditions during the manufacture of the device.

[0039] Terms, definitions and abbreviations used in the description of this utility model

[0040] The following terms, definitions and abbreviations used in the description of this utility model are intended for a better and more precise understanding of this utility model, but do not limit this utility model to the specified wording.

[0041] "Electrical connection device (ECD)" is a device for electrically connecting two or more conductors, comprising a conductive part, devices attached thereto for securing two or more conductors, such as buses, wires, cable lugs, etc. The device may be partially covered with insulating materials and / or contain auxiliary elements, in particular, an insulating part. The most common ECDs include, in particular, screw terminal blocks and spring terminal blocks; however, the claimed utility model is not limited to these types of ECDs. "Conductor" is an element of a cable product (a conductive core) intended for the passage of electric current (GOST 15845-80 "Cable products. Terms and definitions", 01.07.1981). In preferred embodiments of the utility model, the conductor may be understood as a metal, in particular a wire.

[0042] "Wire" is a cable product containing one or more twisted wires or one or more insulated cores, over which, depending on the installation and operating conditions, there may be a light non-metallic sheath, winding and / or braiding made of fibrous materials or wire, and not intended, as a rule, for laying in the ground (GOST 15845-80 "Cable products. Terms and definitions", 01.07.1981). For the purposes of this utility model, the term "wire" also includes uninsulated metal current-carrying wires (cores), one or more insulated cores twisted together and enclosed in a common sheath (cables).

[0043] According to GOST 14312-79 "Electrical Contacts. Terms and Definitions," a "contact connection" or "electrical connection" is defined as an electrical circuit contact intended solely for conducting electric current and not intended for switching the electrical circuit during the intended operation of the device.

[0044] “Contact resistance (contact connection)” according to GOST 14312-79 means the electrical resistance of the contact zone, determined by the effective contact area and equal to the ratio of the voltage drop across the contact junction to the current through this junction.

[0045] "Conductor fastening device" is a device for connecting (securing) conductors to a UES, which may be a screw, spring, or other clamp to ensure a detachable or permanent contact connection. This device ensures electrical contact between the conductor and the conductive part of the UES.

[0046] The term "self-diagnosis," in the context of the claimed utility model, refers to the ability of the UES to diagnose defects in contact connections without the use of additional devices. In the claimed utility model, the UES changes color when a defect occurs due to exceeding a threshold heating temperature, owing to the presence of at least one temperature-sensitive element within the UES. A "temperature-sensitive element (TSE)" includes a product designed to change appearance upon reaching a threshold temperature. The TSE may comprise one or more substances, as well as one or more different materials. Upon reaching the threshold temperature, the TSE may change color or transparency. In the latter case, the visual effect of the device's activation may be due to the color of the substrate located beneath the TSE.A change in the color or transparency of a thermoelectric element upon reaching a threshold temperature may occur due to a chemical reaction, the melting of one or more substances, other phase transitions, or more complex processes. The thermoelectric element may also additionally include solid or gaseous inclusions located within the thermosensitive component; support elements formed in the substrate and / or protective layer material; or an absorbent material onto which the thermosensitive component is applied.

[0047] The present utility model prefers the use of fuel elements whose operation is based on a change in appearance, in particular a change in transparency, upon melting one or more substances, preferably dispersed in a polymer binder. However, the utility model is not limited to the use of such components, and fuel elements may be constructed using a different operating principle.

[0048] A "thermal indicator" is a device that changes its appearance (specifically, color) when heated above one or more threshold temperatures. Typically, a thermal indicator consists of a base designed to secure the thermal indicator to the monitored surface, and one or more temperature-sensitive elements (TEs) located on the front of the base that change appearance when heated. In the case of the claimed utility model, the UES additionally functions as a thermal indicator due to the presence of the TEs on its surface. The following terms are defined using the term "thermal indicator." However, in the case of the claimed utility model, the UES or the part thereof containing the TEs performs the role of the thermal indicator.

[0049] Single-temperature temperature indicators include temperature indicators that have one or several temperature elements that are triggered when one threshold temperature is reached.

[0050] Multi-temperature temperature indicators include temperature indicators that have several heating elements that differ in their response temperature (threshold temperature).

[0051] The term "irreversible" defines thermal indicators that, after heating to the operating temperature, visually change their appearance, in particular their color, in such a way that after cooling below the operating temperature, their appearance does not return to a form that is visually indistinguishable from the original.

[0052] Threshold temperature is the minimum value of the heating temperature of a thermal indicator during the time required to achieve an equilibrium (unchanging over time) state, at which the appearance of the TE of a given thermal indicator changes.

[0053] The "color transition of a temperature-sensitive element" refers to the change in color of the temperature indicator upon activation of the TE. When describing the color transition, the color before activation is first indicated, followed by the color after activation. For example, a TE that is initially white (opaque) and after activation becomes transparent, revealing the color of the black base underneath, is said to have a white-to-black color transition. In some cases, either the TE or the base underneath may bear inscriptions indicating, for example, the numerical value of the TE's threshold temperature, or signal symbols. In this case, the color of the TE before or after activation refers to the color of the background on which such inscriptions or symbols are applied, or the color transition of the main surface of the TE.

[0054] A change in the appearance of a temperature indicator or TE that occurs solely as a result of heating to any of the possible temperature thresholds is called "activation." In the context of the description of this utility model, activation of a temperature indicator is preferably associated with an increase in transparency achieved by melting a substance or group of substances comprising the TE.

[0055] A change in the appearance of a temperature indicator, in particular the color and / or transparency of the TE, that occurs as a result of an external influence other than heating the temperature indicator above the corresponding temperature threshold values, is called a “false triggering of the temperature indicator.”

[0056] "Response speed" is the maximum time required for a temperature indicator or TE to transition from its initial state to its activated state after the TE has heated up to the response temperature, taking into account the specified accuracy of registering when the threshold temperature is exceeded. For the purposes of this utility model, the response speed of the TE is no more than 5 seconds, and typically no more than 2 seconds.

[0057] The term “accuracy of recording the excess of the threshold temperature” means the boundaries of the range of temperature values ​​that meet the following conditions (1) - (3): (1) until the threshold temperature is reached minus the value of the specified accuracy, the corresponding TE does not change its appearance (in particular, it remains opaque to at least part of the visible light), and the temperature indicator in this area does not change its appearance;

[0058] (2) when the threshold temperature is exceeded, taking into account the specified accuracy, the corresponding TE is triggered, in particular, with an increase in transparency achieved by melting one substance or a group of substances included in the TE, and the thermal indicators in this area acquire an appearance different from the original;

[0059] (3) In the case of using a fuel element in which the change in appearance upon reaching a threshold temperature is associated with an increase in transparency achieved by melting one substance or a group of substances included in the fuel element, the exact value of the phase transition temperature of the melting of the substance is within a specified range and is not further established. The accuracy of recording the excess of the threshold temperature defined by this utility model is preferably no more than 5 °C, most preferably no more than 2 °C.

[0060] The term "gas-filled hot-melt material" (GFTM) defines a material comprising a solid phase or phases, as well as a gas phase contained within the cavities of the solid phase. At least one of the solid phases of the GFTM, referred to as the "hot-melt phase," is capable of melting when heated to a threshold temperature. The gas phase is predominantly distributed uniformly throughout the GFTM, with most of the pores interconnected, allowing for the unimpeded distribution and release of gas during heating and / or melting of the material. The gas pressure within the pores may be less than atmospheric pressure, equal to atmospheric pressure, or greater than atmospheric pressure.

[0061] The solid phase of the thermal-sintering material may additionally include particles of a solid substance with a melting point above the threshold, the strength of which predominantly exceeds that of the thermal-sintering phase, polymers that completely or partially coat the thermal-sintering phase, and other inclusions. Such substances or inclusions are used to increase the mechanical strength of the thermal-sintering material.

[0062] The hot-melt phase contains the "active (main) substance of the thermal-melting fluid"—a substance, specifically an organic substance, that determines the melting point of the thermal-melting fluid (the threshold temperature for the operation of the fuel element). The mass content of the active substance in the thermal-melting fluid structure predominantly exceeds the content of other components of the thermal-melting fluid. The term also refers to a mixture of such substances. The term "organic substances" restricts the class of chemical substances that contain carbon atoms bonded to atoms of other chemical elements, with the exception of metal carbides, metal and ammonium carbonates, and carbon oxides.

[0063] The term "gas phase" by default refers to the gas-filled pores within the gas-filled thermocouple. The gas phase can be air, nitrogen, inert gases, or other substances in the gaseous state under the operating conditions of the thermocouple.

[0064] The term "gas phase fraction in a gas-filled slurry mixture" refers to the ratio of the pore volume within the gas-filled slurry mixture to the total volume of the gas-filled slurry mixture, or the ratio of the area of ​​gas-filled sections to the total area of ​​the gas-filled slurry mixture section in one of its cross-sections. For the purposes of this utility model, the gas phase fraction may be determined by one of the following methods.

[0065] The first method involves scanning electron microscopy of the surface of a section of the gas-filled slurry using software that calculates the total external surface area of ​​the sample's solid particles and their agglomerates in the section. The area of ​​gas-filled regions is calculated by subtracting the total surface area of ​​the solid particles and their agglomerates from the area of ​​the analyzed region. To determine the proportion of the gas phase, the resulting value for the area of ​​gas-filled regions is divided by the area of ​​the analyzed region. Measurements are performed on 5-7 sections of the gas-filled slurry, and the average value is calculated.

[0066] The second method is based on X-ray microtomography. Sample preparation is similar to the first method. A section of the gas-phase material of known volume is analyzed using a laboratory digital X-ray tomograph with software capable of calculating the percentage of gas in a given sample volume. Measurements are taken from 5-7 sections of the material, obtaining an average value for the gas phase content, expressed as a percentage.

[0067] Any method for determining the gas phase fraction can be applied to finished products containing gas-phase materials, such as temperature indicators. During sample preparation, a uniform section of the product is cut out and the protective layer is removed to ensure the integrity of the gas-phase material.

[0068] In the context of describing a gas-phase flow system, a "phase" refers to the homogeneous portion of the gas-phase flow system, separated from the remaining portions by a visible interface where some phase characteristics, such as density, composition, or optical properties, abruptly change. The collection of individual homogeneous portions of the system, each possessing identical properties, is considered a single phase.

[0069] The composition of the thermal melting material may additionally include particles of a solid substance with a melting point above the threshold, the strength of which predominantly exceeds the strength of the thermal melting phase, as well as other inclusions.

[0070] The term "GTPM structure" defines the spatial arrangement of solid particles and gas-filled pores in a GTPM sample. The GTPM structure determines its physical, optical, and mechanical properties. Upon reaching a threshold temperature, melting of at least one of the solid phases of the GTPM occurs. During the melting process, the GTPM structure changes, that is, the spatial arrangement of particles and / or volumes of individual phases of the material, their size, and shape. The destruction of the structure may include the following stages: melting of the GTPM particle surface, their compaction, reduction of the pore size within the GTPM and the gas-solid interface area, and particle fusion up to their complete fusion and the formation of a monolithic layer (melt) or a single phase. The process of GTPM structure destruction is accompanied by an irreversible decrease in the volume fraction of the gas phase within the GTPM. The proportion of the gas phase in the material obtained after the activation of the temperature indicator is less than in the initial state of the GTPM.

[0071] When describing a thermoplastic element, particularly one with a thermal-melting phase (TMP), the term "binder" refers to a material or substance, preferably a high-molecular-weight organic compound, that enables the adhesion of solid particles relative to one another. A solid thermal-melting phase binder, in particular, increases the strength of the heat-sensitive material and reduces its abrasion, and can also ensure the adhesion of the thermal-melting phase to the base or absorbent material.

[0072] By "hermetic protective layer" is meant a protective layer that is impermeable to air and water at atmospheric pressure and in the absence of mechanical impact, made without gaps or holes, and tightly connected to the base by welding or gluing in such a way that the joint is also impermeable to air and water at atmospheric pressure and in the absence of mechanical impact.

[0073] The term "absorbent material" refers to a material capable of receiving and retaining, by any means, a molten, hot-melt material, such as a molten active substance or a hot-melt phase. Retention may occur through wetting, adsorption, absorption, or penetration of the melt into pores or other internal cavities of the absorbent material. A special case of an absorbent material is a "sorbent material." Within the framework of this utility model, the absorbent material may be a "porous material," which is a solid material containing free space in the form of cavities, channels, or pores and characterized by a developed surface area. The main parameters of porous materials are porosity, pore size, pore size distribution, and specific surface area. For the purposes of the claimed utility model, the use of "microporous materials" containing pores with a diameter of less than 2 μm is preferred.

[0074] The term "sorption" should be understood in its most general sense as the absorption of various substances by a solid body. The absorbed substance is called a "sorbate," and the absorbing solid or liquid is called a "sorbent." Within the framework of this utility model, when describing TE, the sorbate is a melt of a heat-sensitive material, i.e., a liquid, and the sorbent is various solid absorbent materials. "Absorption" is preferred as a special case of sorption, resulting in the absorption of the sorbate by the entire volume of the sorbent, increasing the sorbent's mass with a slight increase in its volume and changes in its physical properties, particularly its strength.

[0075] The term "support element" or "support element (SE)", when describing a TE, in particular with a GTPM, defines an arbitrary element located in the region of a heat-sensitive material, which has a melting temperature greater than the response temperature of this heat-sensitive material, and which can take on most of the mechanical stress acting on the heat-sensitive material in the transverse direction, thereby preventing significant destruction of the structure of the heat-sensitive material.

[0076] The term “defect” indicates the non-compliance of the control object with the requirements established by the documentation, at least for one indicator.

[0077] The "defectivity factor" is the ratio of the measured temperature rise of the contact connection to the temperature rise measured on the entire section of the busbar or wire, located at a distance of at least 1 m from the contact connection.

[0078] "Excess temperature" is the excess of the measured temperature of the controlled object over the temperature of similar units of other phases located in the same conditions.

[0079] The term "fire-hazardous heating" refers to the heating of an electrical component to a temperature that poses a risk of ignition of one or more of the components' materials. The term "flexible" refers to materials that have the ability to change shape under external influences so that their functional properties remain unchanged upon returning to their original form.

[0080] The term "elasticity" refers to the ability of a material or product, when bent around a cylindrical surface, to conform to its shape without losing its functional properties.

[0081] The term “dielectric” means the property of a material to withstand an electrical voltage applied to it, while the minimum electric field strength at which the breakdown of the material occurs exceeds the electrical strength of air under normal conditions with a layer thickness of 1 cm, which is 3 kV / mm.

[0082] The essence of the utility model

[0083] The objective of this utility model is to create a device for electrically connecting conductors with the ability to irreversibly record the fact that at least one threshold temperature of contact connections has been exceeded.

[0084] The technical result of the claimed utility model consists in increasing fire safety and electrical safety during the operation of electrical equipment by providing an electrical connection of two or more conductors, with a self-diagnostic function, due to the possibility of irreversibly recording the fact of exceeding at least one threshold temperature.

[0085] The technical result is achieved by a device for electrical connection (DEC) of two or more conductors, including a metal conductive part, an insulating part, and at least two devices for securing conductors electrically connected to the conductive part, and at least one temperature-sensitive element (TE), designed with the possibility of an irreversible change in appearance when heated above a corresponding threshold temperature.

[0086] The importance of temperature monitoring of contact connections for improving the operational safety of electrical equipment was already discussed in the "Background Technology" section, where existing methods for solving this problem, including those using thermal indicators, were also discussed. Timely detection of contact connection defects through thermal monitoring in this area helps prevent emergency situations that could lead to equipment damage, fires, and conflagrations. Thermal indicators for two or more conductors are widely used to organize contact connections. They have proven themselves to be reliable and functional means of organizing conductive elements in electrical installations, panels, junction boxes, etc. The device according to this utility model combines the functions of a thermal indicator with the properties of irreversible temperature indicators to monitor the heating of contact connections.The use of irreversible indicators allows not only to detect, but also to record the fact of exceeding the threshold temperature throughout the entire service life.

[0087] The presence of the TE ensures self-diagnosis of the UES, namely, it allows, through continuous thermal monitoring, to visualize the presence of a defect in the contact connection.

[0088] In this device, the TE is applied to the surface of the UES elements in the factory during the UES manufacturing process, ensuring uniformity and high-quality application. If necessary, UES elements are manufactured with the ability to correctly position the temperature-sensitive elements, ensuring the required accuracy of heat detection and visible response during visual thermal monitoring. Thus, the UES is immediately installed in the electrical network with the ability to perform visual thermal indicator monitoring.

[0089] It's worth noting that installing a heat exchanger on a UES already connected to the power grid is unsafe, and in most cases impossible, due to a lack of space. When applying heat-sensitive paint, its layer will be uneven, and the paint itself may interact with the monitored surface and flow upon activation, potentially affecting the contacts themselves. Installing additional heat-sensitive devices, such as temperature-indicating stickers, will cause mechanical stress on the installed electrical connection and cause it to become loose. These factors will reduce the safety of electrical equipment operation and the quality of temperature-indicating monitoring.

[0090] The ability to use multiple TEs with different threshold temperatures allows not only to detect the presence of a defect but also to determine its progression (initial stage, emergency defect, fire hazard), as well as to determine the dynamics of the defect's development, to compare the heating temperatures of identical contact connections, components, or equipment assemblies, and to determine the excess temperature and defect rate. Thus, the entire set of features characterizing an electrical connection device for two or more conductors with a self-diagnostic function ensures the solution of the stated problem and the achievement of the specified technical result.

[0091] In preferred embodiments, the UES is designed with the possibility of electrically connecting wires and using in distribution boards with a voltage of up to 1000 V, which is due to the use of UES designs known from the prior art.

[0092] In specific cases, the largest linear dimension of the device does not exceed 10 cm. The linear dimension of the UES is one of the important parameters for the claimed solution, since, on the one hand, the UES must be compact, due to the small distance between the electrical equipment elements, and on the other hand, the UES according to this utility model must have a place (site) for placing the TE, accessible for visual monitoring of their operation.

[0093] In some embodiments, the conductor securing devices may be implemented as a screw connection, and the ED itself may be a screw terminal block (Fig. 3), a screw terminal, a neutral busbar (Fig. 1), or a screw clamp (Fig. 4). In other embodiments, the conductor securing devices are implemented as a spring connection, and the ED itself may be a spring terminal block (Fig. 2).

[0094] The insulating part may be, in particular, a DIN rail mount (Fig. 1), a housing (Fig. 2), a protective screen (Fig. 3a), or a TE. The insulating part improves the safety of use and maintenance of the UES.

[0095] The thermoelectric cells used in the device according to this utility model may differ in the operating principle of the temperature-sensitive component included within them. When selecting the type of temperature-sensitive component, the characteristics of each must be taken into account. Thermoelectric cells are known in the prior art to rely on a chemical reaction of their constituent substances, which begins upon reaching a certain temperature or upon melting. Prolonged exposure of thermoelectric cells based on a chemical reaction at a temperature slightly below the threshold value can lead to premature activation, since the degree of chemical reaction is determined not only by temperature but also by time. Therefore, such thermoelectric cells can be used in UES with a short service life, such as those used temporarily. There are thermoelectric cells based on the mechanical destruction of one of the temperature-sensitive components upon reaching a threshold temperature.As a rule, such TEs are large in size and can only be installed at large power plants.

[0096] The most common thermoelectric cells are those based on phase transition, primarily the melting of a heat-sensitive component, due to their high precision, response speed, and ability to maintain their original appearance indefinitely at temperatures slightly below the threshold. Prior art thermoelectric cells based on the phase transition of a heat-sensitive component can be classified by the operating principle that changes the device's appearance: a change in the transparency of the heat-sensitive component upon melting, dissolution of dyes in the melted heat-sensitive material, or absorption of the melted heat-sensitive component into a porous substrate.

[0097] FCs in which the change in appearance occurs due to the dissolution of a solid dye in a melt of a fusible substance usually have a short service life due to solid-phase diffusion of the dye.

[0098] The penetration of the molten component into the porous substrate, on the one hand, ensures a high contrast of the color transition, since the color of the substrate may differ from the original color of the solid hot-melt component, but on the other hand, the crystallization of the substance in the pores of the substrate upon cooling can lead to reversibility (returnability) of the color indication.

[0099] The use of TEs in a device whose operating principle is based on an irreversible increase in the transparency of a heat-sensitive component due to its melting has a number of advantages over the operating principles described above: high response accuracy due to the use of purified stable substances with a narrow melting point range; ensuring the irreversibility of response (even with a long-term exposure of the triggered TE at a temperature below the threshold); high opacity of the heat-sensitive layer, allowing the production of TEs of small thickness; visibility of the triggered device, ensured by the contrast of the color transition (e.g., white - black) in the case of using a polymer film of a certain color, in particular, black; the possibility of simplifying the assessment of the equipment condition during inspections due to the appearance of a special hazard sign or symbol (e.g., a flame sign, an exclamation mark, etc.) upon triggering of the TE.), located on the polymer film (if used) under a layer of hot-melt material; ensuring the ability to register local overheating due to the fact that only the area of ​​the TE that is heated above the threshold temperature is subject to melting, while the appearance of the remaining areas of the TE is preserved; high response speed due to the use of a thin layer of heat-sensitive component; long service life.

[0100] Based on this, the present utility model prefers the use of TEs whose heat-sensitive components operate based on a change in appearance due to melting, specifically a change in transparency. However, the utility model is not limited to the use of such components, and TEs can be constructed using components operating on different principles.

[0101] When thermosensitive elements (TEs) whose operation is based on a change in transparency are triggered, the color of the device portion or the film (if present) located underneath them is revealed. If the TEs are applied to the film, each TE may trigger the same color transition or different color transitions, depending on the coloring of the corresponding TE. It is preferable to color the film underneath all TEs black. In this case, all TEs are preferably white in their initial state, thus ensuring a visually observable white-to-black transition upon activation.

[0102] The use of this type of TE enables, among other things, the creation of a heat-sensitive material structure such that, in the case of localized heating, the TE's appearance changes only in the region where the threshold temperature was exceeded, while maintaining the original appearance of other unheated regions of the TE (Fig. XB). Furthermore, the boundary of the heated region is determined with high accuracy, typically within 1-2 mm. To further enhance this characteristic, it is preferable to use gas-filled hot-melt materials (GFTM), which will be discussed below.

[0103] The response time of at least one TE according to this utility model is no more than 5 seconds and is ensured by the TE's operating principle. This speed is necessary to detect short-term heating events caused by peak (emergency) loads or, for example, short-circuit currents. A response time of no more than 5 seconds, and preferably no more than 2 seconds, can be achieved, for example, by the TE's operating principle based on the melting of the TE's active substance.

[0104] The accuracy of recording the excess of the threshold temperature determined by this utility model is preferably no more than 5 °C, most preferably no more than 2 °C, which is also ensured, among other things, by the operating principle of the TE.

[0105] It is preferable to use fuel cells that ensure the original appearance of the temperature indicator remains unchanged when the device is cooled to 20°C and maintained at this temperature for at least one month, preferably one year or more. In preferred embodiments, the service life of the fuel cell is at least five years, preferably at least ten years, and most preferably at least 25 years.

[0106] Increasing the service life of fuel cells is an important parameter for their use in power plants. This is due to the fact that power plants have a relatively long service life (5-25 years), and therefore, it is necessary for the fuel cells to maintain their functional characteristics throughout the entire service life of the power plant.

[0107] When selecting a TE, it is necessary to consider the dielectric properties of the components it comprises. Preferably, the TE should have a dielectric strength of at least 5 kV / mm. Examples of materials with sufficient dielectric strength will be discussed in the section on the embodiment of the invention.

[0108] The area of ​​at least one TE is preferably at least 2 mm 2 , most preferably 4-25 mm 2 , to ensure the necessary visibility of the operation of the TE. The TE are preferably positioned in such a way as to ensure the possibility of comparing the temperature of different contact connections.

[0109] Below are various, but not limiting, options for the arrangement of the TE relative to the contact connections.

[0110] In the first case, the device comprises at least one TE placed at an equal distance from at least two conductor securing devices (Fig. 1). This TE arrangement enables thermal monitoring in the area of ​​at least two conductor securing devices using a single TE.

[0111] In the second case, the device contains at least two TEs with identical threshold temperatures, each of which is positioned near a corresponding conductor securing device (Fig. 2g). Thus, each TE is positioned to monitor the thermal state in the area of ​​the corresponding conductor securing device.

[0112] In the third case, the device comprises at least one group of TEs, including at least two TEs with different threshold temperatures, wherein at least one group of TEs is located at the same distance from at least two conductor securing devices (Fig. 2b). This arrangement of the group of TEs enables monitoring of the thermal state in the area of ​​at least two conductor securing devices and the ability to compare the highest temperatures of different contact connections.

[0113] In the fourth case, the device comprises at least two groups of TEs, each with a different threshold temperature, each positioned near a corresponding conductor securing device (Fig. 10). Thus, each group of TEs is positioned to monitor the thermal state in the area of ​​the corresponding conductor securing device and to compare the highest temperature of the various contact connections.

[0114] In special cases, the TE can be applied to the metal conductive part of the UES. In this case, the high thermal conductivity of the conductive part ensures rapid heating of the TE and increases the accuracy of threshold temperature detection due to reduced heat dissipation. Preferably, the TE can be located in a recess (Fig. 6) made on the metal conductive part. This arrangement of the TE offers several advantages: protection of the TE, in particular the heat-sensitive material, from mechanical damage and abrasion; prevention of dripping of the heat-sensitive material during melting (activation); increased TE response speed by reducing the thickness of the conductive part in the TE area and increasing the contact area of ​​the TE with the heated conductive part.

[0115] It should be noted that the location of the TE in a recess can be used when placing TE on other elements of the UES.

[0116] In one embodiment, at least one TE may be secured to a metal conductive part using a dielectric material, preferably an adhesive, in particular an adhesive based on acrylic, polyurethane, rubber, silicone, or PVC polymers, or preferably using a polymer film, preferably made of halogen-containing polymers, most preferably polyvinyl chloride. The principle for selecting a dielectric material will be discussed below.

[0117] The TE may have a layered structure comprising a permanently tacky adhesive layer, a dielectric material, and at least one temperature-sensitive material, preferably dispersed within the binder. The temperature-sensitive material comprises at least one substance or mixture of substances having a melting point near the TE's response temperature.

[0118] These implementation options are similar to using a sticker; however, since the TE placement is performed at the factory during the UES manufacturing process, the highest quality and most accurate placement is ensured. This improves the speed, accuracy, and reliability of TE operation. Factory application also allows for the use of films (substrates) of minimal thickness, which are impossible to apply during installation. Furthermore, factory application of the TE prevents loosening of the electrical connection when installing an additional indicator device on an already installed UES.

[0119] The UES can be designed with the possibility of being mounted on a DIN rail, in particular, it can have additional fastening elements made of insulating material (Fig. 1a).

[0120] In other embodiments, at least one TE may be applied to an insulating portion of the device, preferably the housing (Fig. 2b, d, 4b) or under a protective screen. This arrangement is particularly relevant in cases where the conductive elements of the resistive electronic device are housed within the housing. An example of such a device is a spring-loaded terminal.

[0121] In preferred embodiments, at least one resistive element is located no more than 10 mm, preferably no more than 5 mm, from at least one conductor securing device. This is because, when a contact defect occurs, heat is generated at the point of contact between the conductor and the resistive element, transferring it to the conductive part. The heat quickly dissipates as the distance from the heating point increases. Furthermore, the accuracy of overheating detection, in accordance with current regulations, should not exceed 10°C. The distance over which the device temperature decreases by 10°C can be roughly estimated based on Fourier's law of thermal conductivity and Newton-Richmann's law.

[0122] In accordance with Fourier's law of thermal conductivity, the heat flux removed through a unit area per unit time will be proportional to the thermal conductivity coefficient of the material and the temperature gradient: q = - X (ΔT l), (1) where X is the specific thermal conductivity coefficient, and AT is the change in temperature over the length A / .

[0123] We will assume that the same heat flow is dissipated into the environment in accordance with the Newton-Richmann law in direct proportion to the difference between the temperature of the device material and the ambient air temperature: q = a-(T- T 0К p), (2) where a is the heat transfer coefficient between the device and the environment (air), T is the temperature of the device, T окр - ambient temperature.

[0124] From these relationships, equating the two heat flows, we obtain the following relationship for the length:

[0125] M = XLT / [a- T- T окр )]. (3)

[0126] As a typical value of the heat transfer coefficient we take a equal to 3 W / (m 2 *K). We'll assume the thermal conductivity coefficient for the material of the device's conductive part to be 45.4 W / (m*K). We'll assume the ambient temperature to be 20°C and the temperature of the conductor mounting fixture to be 70°C. With these parameters, a temperature gradient of AT = 10°C will correspond to a length of D1 ~ 30 mm.

[0127] However, it is not always possible to place the TE on the conductive part or on the conductor fastening devices. When placing the TE on the insulating parts and housing of the UES, it is necessary to take into account the low thermal conductivity of the materials from which these parts are made. In this case, the thermal conductivity coefficient of the material of the dielectric part of the UES can be assumed to be 0.2 W / (m*K) (the average thermal conductivity coefficient for polymeric materials, composite materials, and ceramics). Then, with the same temperature difference between the contact fastening device and the surrounding environment, the value of A / will be approximately 13 mm. Based on averaging the UES parameters, their installation locations, the environments in which they are used, the range of recorded temperatures, etc., known to the authors based on conducted research and experience in this field of technology, the authors of the present utility model have experimentally established that, in order to ensure the accuracy of recording threshold temperature exceedances, it is preferable to place at least one TE at a distance of no more than 5 mm from at least one conductor securing device. When implementing multi-temperature thermal monitoring (several TEs with different threshold temperatures), it is preferable to place the TEs at the same distance from the conductor securing device or sequentially in order from lower to higher temperatures. In some embodiments, sequential placement of the TEs is possible; in this case, the distance between the boundaries of adjacent TEs preferably does not exceed 5 mm, most preferably does not exceed 3 mm.

[0128] In some embodiments, at least one TE may be coated with a protective layer or polymer varnish, transparent to at least some visible light, which further protects the TE's temperature-sensitive material from external environmental influences, humidity, UV radiation, and mechanical damage. The protective layer also further extends the device's service life and prevents the temperature-sensitive material from leaking when a threshold temperature is exceeded.

[0129] In preferred embodiments of the utility model, the dielectric material and / or protective layer are flexible and made of a thermoplastic polymer. Preferably, the dielectric material and / or protective layer contain halogen atoms, primarily chlorine atoms, and are polyvinyl chloride, most preferably cast polyvinyl chloride. The halogen-containing dielectric material and / or protective layer provide a dielectric strength of at least 5 kV / mm and are flame-resistant. Furthermore, halogen-containing materials exhibit good adhesion, which is an additional factor ensuring the safety of the claimed device.

[0130] In certain embodiments, information elements may be applied to the dielectric material and / or transparent protective layer, including information for marking electrical components or color-coded phases. Specifically, information elements applied to the front surface of the polymer film and / or transparent protective layer may include inscriptions containing color, alphabetic, numeric, or alphanumeric marking information. In one case, the information elements may contain information about the end-of-life date of the device.

[0131] The dielectric material and / or transparent protective layer may also be colored to comply with established electrical equipment marking standards. To increase the visibility of both the TE itself and its operation, and thus further enhance equipment safety, the dielectric material and / or transparent protective layer may have reflective or luminescent properties.

[0132] In specific cases, the UES may include at least one temperature-sensitive material capable of reversibly changing color upon reaching a corresponding threshold temperature (Fig. 9). For example, the dielectric material may be colored using a substance (dye) capable of reversibly changing color upon heating, or such a substance may be incorporated into at least one TE. The use of substances capable of reversibly changing color upon heating allows personnel to be informed of overheating events during inspection. Heating of the device during inspection indicates that the equipment is currently in emergency mode and may pose a source of increased danger. Furthermore, the activation of the primary TE, which irreversibly changes appearance upon exceeding the corresponding threshold temperature, informs personnel of overheating events and their maximum temperature that occurred BEFORE the inspection.Thus, the presence of a substance capable of reversibly changing color when heated further increases the safety of operation of both the declared device and the equipment as a whole.

[0133] In particular cases, at least one TE may have one or more properties aimed at enhancing the technical result, in particular:

[0134] The TE includes a gas-filled hot-melt material (GFTM), preferably, the proportion of the gas phase in which is at least 10 vol.%; contains an absorbent material; contains support elements; includes at least one solid organic substance with a molecular weight of less than 2 kDa; includes at least one solid organic substance containing a structural fragment C n H(2n+i), where n is greater than or equal to 5, and is preferably selected from the group consisting of fatty aliphatic acids containing structural fragments C nH(2n+i) with n greater than or equal to 12; salts of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 5; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C n H(2n+i) with n greater than or equal to 5; amides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 5; anhydrides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 10; fatty aliphatic alcohols containing structural fragments C п H(2n+1) with n greater than or equal to 14; fatty aliphatic amines containing structural fragments C n H(2n+i) with n greater than or equal to 17; nitriles of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 19.

[0135] Preferred, but not limiting, examples of solid organic matter are: palmitic acid, stearic acid, behenic acid, tetracosane, erucamide, stearic alcohol, cetyl alcohol, salts of saturated fatty carboxylic acids of rare earth metals, in particular lanthanum, yttrium, ytterbium, scandium.

[0136] The use of a thermal-melting material (TMP) ensures high device response accuracy and a long service life, and enables the use of minimal-thickness fuel cells while maintaining high opacity and a high luminance factor, irreversibly triggering at high speed and precision. These characteristics are achieved thanks to the TMP's unique structure, which includes, in addition to a solid phase or phases, at least one of which contains a hot-melt substance or a mixture thereof, voids filled with a gas phase. Until a threshold temperature is exceeded, the gas phase within the TMP is distributed predominantly uniformly. This creates multiple gas-solid interfaces at which light is refracted and reflected. This TMP structure makes it opaque to at least some visible light, while maintaining a thinner layer thickness than a similar substance without a gas phase.

[0137] The structure of the thermal-melting device also enables the recording of the boundary of thermal fields heating the surface of the test object by changing the appearance of only that portion of the thermal-melting device that was heated above the corresponding threshold temperatures, while maintaining the original appearance of the remaining portion. The hot-melting materials used in this utility model may contain a single active substance or a mixture of active substances. The active substance or mixture of active substances is preferably a solid organic substance or a mixture of such substances. The specific substance is selected such that upon reaching the corresponding threshold temperature in the range of no more than 5°C, preferably no more than 2°C, it melts, resulting in a visually observable change in the device's appearance.

[0138] In preferred embodiments of the utility model, at least one active (main) substance of the hot-melt material has a molecular weight of less than 2 kDa (2000 amu). FCs with a low-molecular-weight active substance of the hot-melt material have a narrow melting point range, which leads to increased accuracy in detecting threshold temperature exceedances. The use of low-molecular-weight substances as active substances is only possible in HTPMs, since in the absence of a gas phase within the hot-melt material, multiple crystallization centers may form during cooling of the FC with a low-molecular-weight hot-melt substance, leading to the formation of an opaque solid and the return of the FC to its original form, i.e., to the reversibility of its operation.

[0139] The use of active substances containing one or more aliphatic hydrocarbon chains is preferable due to the fact that such organic substances have a crystalline packing in which the elongated structural fragments of linear hydrocarbons are oriented parallel to each other, which ensures the formation of predominantly flat particles such as scales, plates or fibers (Kitaigorodskii A.I. Molecular Crystals: Monograph. Moscow: Nauka. 1971. 424 p. pp. 228-232). Such crystalline packing causes the anisotropy of the solid organic substance, as a result of which the properties of the material in the direction parallel to the surface of the base and the protective coating differ from the properties of the material in the direction perpendicular to the surface of the base and the protective coating.The anisotropy of the properties of a hot-melt material affects the strength of the material under bending and mechanical stress: applying stress in directions close to perpendicular to the base surface will not lead to damage to the material (Kitaigorodskii A.I. Organic crystal chemistry: monograph. Moscow: Publishing House of the Academy of Sciences of the USSR, 1955. 558 p. pp. 134-136).

[0140] Use of aliphatic compounds with C n H(2n+i), where n is greater than or equal to 5, is also preferable due to the fact that, due to its crystalline packing, the heat-sensitive material exhibits the ability to bend and stretch / compress without deformation and loss of functional properties due to layer-by-layer shear of particles.

[0141] The described shape and characteristics of the active substance particles are preferred, but do not limit the claimed utility model. They can also be achieved using substituted aromatic and heteroaromatic compounds. In this case, the substituents can be either long hydrocarbon fragments, which further facilitate the formation of planar-oriented particles, or heteroatomic substituents, which promote layered packing of molecules, in which bulky heteroatoms are located in the interlayer space (Bokiy, G.B. Crystal Chemistry: Monograph. 3rd revised and enlarged ed. Moscow: Nauka, 1971. 401 p. pp. 362-365).

[0142] However, it should be noted that the claimed utility model is not limited exclusively to the use of substances with a molecular weight of less than 2 kDa, which include one or more aliphatic hydrocarbon chains with a structural fragment C nH(2n+i), where n is greater than or equal to 5. In particular, the hot-melt material may include at least one solid polymeric organic substance, selected without limitation from polyethylene, phenolic and phenol-acetylene resins, waxes, paraffins and other substances that provide an increase in the transparency of the material upon reaching the threshold temperature and possessing the necessary properties.

[0143] In preferred embodiments, the volumetric gas content of the thermal fusible composite is at least 10%, most preferably at least 50%. Using a thermal fusible composite with this volumetric gas content allows for a significant reduction in the thickness of the hot-melt material layer to ensure adequate hiding power, compared to the thickness of a non-gas-filled material required to achieve the same hiding power. To prevent delamination of the thermal fusible composite during heating due to thermal expansion of the gas phase, it is preferable for the pressure within the thermal fusible composite to be below atmospheric pressure, and for most of the pores filled with the gas phase to be non-isolated, i.e., to communicate with one another.

[0144] The use of at least one gas-phase thermal sensor with the specified volumetric gas content increases the service life of the device and improves the reliability of overheating detection by preventing the aggregation of solid organic particles separated by the gas phase. This virtually eliminates the possibility of the temperature indicator's appearance returning to its original state when the triggered device is exposed to low temperatures and temperature fluctuations. Increasing the volumetric gas content in the gas-phase thermal sensor used reduces the apparent density of the gas-phase thermal sensor. This reduces the amount of heat required to melt the gas-phase thermal sensor and increases the response speed of the fuel element. In preferred embodiments of the invention, to ensure irreversibility of the fuel element's response, the volumetric gas content in the gas-phase thermal sensor during melting is reduced by at least a factor of two.

[0145] The temperature-sensitive material can be placed on an absorbent or microporous material. In this case, when the thermoelectric element is triggered, the molten thermo-melting material is absorbed or penetrated by the absorbent material. The use of an absorbent material prevents the melted thermo-sensitive layer from partially becoming opaque when the triggered thermoelectric element is subjected to mechanical stress, such as vibration.

[0146] In one embodiment of the utility model, a polymer film may be used as the dielectric material, comprising multiple support elements between which a hot-melt component of the TE is positioned. The TE may also contain multiple support elements located within the heat-sensitive material. This protects the TE from mechanical impacts (pressure, friction, increased pressure, etc.) by redistributing the load from the heat-sensitive material to the support elements.

[0147] Brief description of the drawings

[0148] The utility model will be better understood from the description, which is not limiting in nature and is given with reference to the accompanying drawings, which depict:

[0149] Fig. 1 - A variant of the implementation of the UES in the form of a neutral bus with fastening on a DIN rail, 1a - a general view of the device, 1b - a view of the UES from above, with the TE placed on the conductive part in the form of a single zone, 1c - a view of the UES from above, with the TE placed on the conductive part in the form of a single zone, when the TE is triggered in the area of ​​one contact connection.

[0150] Fig. 2 - A variant of the implementation of the UES in the form of a spring terminal block, 2a - a general view of the device, 2b - a view of the UES from below, with a group of TEs placed on the housing, wherein the TEs have different threshold temperatures, 2c - a view of the UES from below, with a group of TEs placed on the housing, when two TEs are triggered in the area of ​​all contact connections, 2g - a view of the UES from below, with TEs placed on the housing, wherein the TEs have the same threshold temperatures, 2d - a view of the UES from below, with TEs placed on the housing, when the TE is triggered in the area of ​​one contact connection.

[0151] Fig. 3 - A variant of the implementation of the UES in the form of a screw terminal block, 3a - a general view of the device, 36 - a view of the UES from above, with TE placed on the conductive parts, wherein on each serial electrical connection with conductors A, A', B, B', C, C', D, D' the number and location of TE is different.

[0152] Fig. 4 - A variant of the implementation of the UES in the form of a screw clamp, 4a - a general view of the device, 4b - a view of the device from above, with TEs placed on the insulating part, 4c - a view of the UES from above, with TEs placed in recesses on the insulating body, when the TEs are triggered in the area of ​​three contact connections that do not form a contact connection with each other.

[0153] Fig. 5 - Top view of a section of a screw terminal block in the area of ​​two devices for fastening conductors that form an electrical connection, with a TE made in the form of a single zone and located on the conductive part between the devices for fastening conductors. 5a - initial view of the device, 5b - view of the device after exceeding the threshold temperature in the area of ​​conductor A.

[0154] Fig. 6 - Side view of a section of a screw terminal block in the area of ​​two devices for fastening conductors that form an electrical connection, with a TE made in the form of a single zone and located in a recess on the conductive part between the devices for fastening conductors and covered on top with a protective layer.

[0155] Fig. 7 - Side view of a section of a screw terminal block in the area of ​​two devices for securing conductors that form an electrical connection with TEs located on the conductive part using a dielectric material and covered on top with a protective layer.

[0156] Fig. 8 - Top view of a screw terminal block in which, in the area of ​​each two devices for fastening conductors (A, A', B, B', C, C', D, D') forming an electrical connection, a group of TEs is located, having different threshold temperatures, and located on the conductive part between the devices for fastening conductors and covered on top with a protective layer. 8a - initial view of the device. 8b - view of the device after exceeding the highest threshold temperature in the area of ​​conductor A, and exceeding the first threshold temperature in the area of ​​conductor A'.

[0157] Fig. 9 - Top view of the neutral bus section in the area of ​​three devices for fastening conductors and TE near each contact connection, located on the conductive part, wherein the TE have the same threshold temperatures, as well as with a reversible temperature-sensitive material. 9a - initial view of the device. 9b - view of the device after exceeding the threshold temperature of the main (irreversible) TE and the reversible temperature-sensitive material. 9c - view of the triggered device after cooling to room temperature.

[0158] Fig. 10 - Top view of a section of the neutral busbar in the area of ​​three devices for securing conductors with three groups of TEs, each of which is located near the corresponding contact connection (A, B, C), located on the conductive part, wherein each group includes two TEs with different threshold temperatures. 10a - initial view of the device. 10b - view of the device after exceeding the maximum threshold temperature in the area of ​​conductor B, and exceeding the first threshold temperature in the area of ​​conductors A, C.

[0159] Detailed description of the drawings

[0160] In Fig. 1 the embodiment of UES 1 in the form of a bus with fastening on a DIN rail is shown. 1a - general view of the device, which shows the conductive part 2, holes for fastening (clamping) conductors 3, screws 4, threaded holes for screws 5, fastening on a DIN rail made of insulating material 6. 1b - top view of UES 1, with TE 7 placed on the conductive part 2 in the form of a single zone. In this case, the device is designed for single-temperature temperature indicator control. TE 7 is applied to the conductive part 2 using a dielectric material 8 with reflective properties. 1c - top view of UES 1, with TE 7 placed on the conductive part 2 in the form of a single zone, upon operation of TE 7 in the area of ​​one contact connection, due to the use of heat-sensitive materials, the action of which is based on the melting of the heat-sensitive component with a change in transparency.In this case, it is shown that the heat-sensitive material in its initial state is white in color, and when the threshold temperature is exceeded, the material melts, becoming transparent and revealing the color of the dielectric material 8, which in this area is colored black 9 and has information elements 10 showing the numerical value of the threshold temperature.

[0161] Fig. 2 shows an embodiment of the UES 1 in the form of a spring terminal block. 2a is a general view of the UES 1, which shows the insulating housing 11, the lever of the spring mechanism 12, the holes for fastening (clamping) the conductors 3. 2b is a bottom view of the UES 1, with a group of TE 7 placed on the housing 11, wherein the TE 7 have different threshold temperatures. In this case, the device is designed with the possibility of multi-temperature temperature indicator monitoring, namely monitoring the excess of three threshold temperatures. TE 7 is applied to the housing using a dielectric material 8, on which information elements 10 are also applied, showing the numerical value of the threshold temperature. 2c is a bottom view of the UES 1, with a group of TE 7 placed on the housing 11, upon the operation of two TE 7 in the area of ​​all contact connections.In this case, it is shown that the heat-sensitive materials are white in their initial state, and when the corresponding threshold temperature is exceeded, the material melts, becoming transparent and revealing the color of the dielectric material 8, which is painted black 9 in this area. 2g is a bottom view of the UES 1, with TEs 7 placed on the housing 1, wherein TEs 7 have the same threshold temperatures. TEs 7 are applied to the housing 11. 2d is a bottom view of the UES 1, with TEs 7 placed on the housing 11, when TE 7 is triggered in the area of ​​one contact connection. In this case, it is shown that the heat-sensitive materials are white in their initial state, and when the corresponding threshold temperature is exceeded, the material melts, becoming transparent and revealing the color of the housing; in this case, the housing is transparent, thereby revealing the color of the conductive part 2, located under the housing in this area.

[0162] Fig. 3 shows an embodiment of the UES 1 in the form of a screw terminal block. 3a is a general view of the UES 1, which shows the insulating housing 11, the conductive parts 2, the holes for fastening (clamping) the conductors 3, the screws 4, the protective screen 14. 3b is a top view of the UES 1, with the TE 7 placed on the conductive parts 2, wherein for each series electrical connection with conductors A, A', B, B', C, C', D, D' the number and location of the TE is different, the holes in the housing for fastening the UES 13 are also shown.

[0163] Fig. 4 shows an embodiment of the UES 1 in the form of a screw clamp. 4a is a general view of the UES 1, which shows the insulating housing 11, holes for fastening (clamping) conductors 3, screws 4, threaded holes for screws 5, holes in the housing for fastening the UES 13. 4b is a top view of the UES 1, with TEs 7 placed on the insulating housing 11, wherein the TEs 7 have the same threshold temperature. 4c is a top view of the UES 1, with TEs 7 placed on the insulating housing 11, when the TEs 7 are triggered in the area of ​​three contact connections (A, E', L), which do not form an electrical connection with each other. In this case, it is shown that the heat-sensitive materials are placed on the housing using a dielectric material (not shown), in the initial state they are white, and when the corresponding threshold temperature is exceeded, the material melts, becoming transparent and revealing the color of the dielectric material in this area.

[0164] Fig. 5 shows a top view of a section of screw terminal block 1 in the area of ​​two devices for fastening conductors, with the formation of an electrical connection between conductors A, A' and TE 7, executed in the form of a single zone and located on the conductive part 2. 5a is the initial view of the device. In this case, it is shown that the heat-sensitive material in the initial state is white. 5b is a view of the device after exceeding the threshold temperature in the area of ​​conductor A, that is, in the area of ​​one contact connection, due to the use of heat-sensitive materials, the action of which is based on the melting of the heat-sensitive component with a change in transparency. In this case, it is shown that when the threshold temperature is exceeded, the material in the area heated above the threshold temperature melts, becoming transparent and revealing the color of the material underneath it.The top of the TE is covered with a transparent protective layer 15, onto which information elements 10 are applied, showing the numerical value of the threshold temperature.

[0165] Fig. 6 shows a side view of a section of a screw terminal block 1 in the area of ​​two devices for fastening conductors that form an electrical connection, with a TE 7 made in the form of a single zone and located in a recess 16 on the conductive part 2 between the devices for fastening conductors and covered on top with a protective layer 15. In this case, the TE 7 includes an absorbent material 17 of black color and a heat-sensitive material 18, which in the initial state is white, and when melted, the heat-sensitive material melts and penetrates into the absorbent material, revealing its color.

[0166] Fig. 7 shows a side view of a section of a screw terminal block in the area of ​​two devices for fastening conductors that form an electrical connection, with TE 7 located on the conductive part 2 between the devices for fastening conductors and covered with a protective layer 15 on top. In this case, TE 7 have the same threshold temperatures. In this case, TE 7 includes a black dielectric material 8 and a heat-sensitive material 18, which in its initial state is white, and upon melting, the heat-sensitive material 18 melts and reveals the color of the dielectric material 8.

[0167] In Fig. 8 is shown a top view of a screw terminal block 1 with an insulating housing 11, in which in the area of ​​each two devices for fastening conductors (A, A', B, B', C, C', D, D'), forming an electrical connection, a group of TE 7 is located, having different threshold temperatures, located on the conductive part 2 between the devices for fastening conductors and covered from above with a protective layer 15. 8a is the initial view of the device. In this case, it is shown that the temperature-sensitive material in the initial state is white. 8b is a view of the device after exceeding the highest threshold temperature in the area of ​​conductor A, and exceeding the first threshold temperature in the area of ​​conductor A'. Thus, it is shown that due to the use of temperature-sensitive materials, the action of which is based on the melting of the temperature-sensitive component with a change in transparency, it is possible to compare the temperature of the greatest heating of various contact connections.In this case, it is shown that when the threshold temperature is exceeded, the material in the region heated above the threshold temperature melts, becoming transparent and revealing the color of the material beneath. The top of the FC is covered with a transparent protective layer 15, onto which information elements 10 are applied, displaying the numerical values ​​of the threshold temperatures.

[0168] Fig. 9 shows a top view of a section of the neutral bus in the area of ​​three devices for fastening conductors and TE 7 near each device, located on the conductive part 2, wherein TE 7 have the same threshold temperatures. TE 7 is applied to the conductive part 2 using a dielectric material 8, on which information elements 10 showing the numerical value of the threshold temperature are also applied. In this case, a reversible temperature-sensitive material 19 is applied to the sections of the dielectric material 8 free from the main TE 7. 9a is the initial view of the device. In this case, it is shown that the temperature-sensitive material of the main TE 7 in the initial state is white and the reversible temperature-sensitive material 19 in the initial state is green. 9b is a view of the device after the threshold temperature of the main (irreversible) TE 7 and the reversible temperature-sensitive material 19 is exceeded.In this case, it is shown that upon activation of the main TE 7, the color of the dielectric material 8 (painted black in this area, with an information element applied, showing the numerical values ​​of the threshold temperatures 10) appears, and upon activation of the reversible heat-sensitive material 19, the color of the dielectric material 8 (painted red in this area) appears. 9c - the appearance of the activated device after cooling to room temperature. In this case, it is shown that upon cooling, the appearance of the main TE 7 does not change, and the reversible heat-sensitive materials 19 return to their original appearance.

[0169] Fig. 10 shows a top view of a section of the neutral busbar in the area of ​​three devices for fastening conductors with three groups of TE 7, each of which is located near the corresponding contact connection (A, B, C), located on the conductive part 2, wherein each group includes two TE 7 with different threshold temperatures. 10a is the initial view of the device. 10b is a view of the device after exceeding the maximum threshold temperature in the area of ​​conductor B, and exceeding the first threshold temperature in the area of ​​conductors A, C. In this case, the provision of the possibility of comparing the temperature of the greatest heating of various contact connections is also shown.

[0170] Implementation of a utility model

[0171] General technology of manufacturing the device

[0172] Electrical connection devices (ECDs) for connecting two or more conductors can have various designs and structures. Specifically, ECDs can include screw terminal blocks, screw terminals, neutral busbars, screw clamps, terminal blocks, spring-loaded terminal blocks, or feed-through terminals. Therefore, their manufacturing processes and some characteristics will differ.

[0173] UES are often used for electrical connections of wires and can be used in distribution boards with voltage up to 1000 V.

[0174] Often, in places where the UES is installed, there are restrictions on the space for installing the UES; therefore, it is preferable that the largest linear dimension of the device does not exceed 10 cm.

[0175] It should be noted that existing UES do not provide space for the placement of TE, therefore, if necessary, the corresponding areas of the device elements can be increased, preferably for the placement of TE with an area of ​​at least 2 mm 2 , most preferably 4-25 mm 2 To ensure visible operation of the device. When using a single TE placed with the ability to thermally monitor multiple contact connections, the TE area can be increased proportionally to the number of conductors. However, the location (site) for the TE placement must be accessible for visual inspection of the TE operation after installation of the UES.

[0176] During device manufacturing, one or more recesses may be formed in the surface on which the TE will be located. Positioning the TE in a recess protects the TE, particularly the heat-sensitive material, from mechanical damage and abrasion; prevents the heat-sensitive material from flowing during melting (activation); and increases the TE's response speed by reducing the thickness of the resistive element in the TE area and increasing the contact area of ​​the TE with the heated conductive part. Preferably, the TE is positioned in a recess formed on the metal conductive part; however, recesses filled with TE may also be located on other elements of the resistive element. Generally, the resistive element includes a metal conductive part and at least two devices for securing the conductors.In addition, devices may, without limitation, include insulating elements that enhance the safety of use and maintenance of the UES, such as a housing and protective screen. The UES may also include elements for mounting on a DIN rail.

[0177] The metal conductive part must have high thermal and electrical conductivity; in particular, it can be made of copper, aluminum, or their alloys to ensure a reliable electrical connection between two or more conductors. In some cases, the metal conductive part may be tin-plated to prevent oxide film formation.

[0178] The conductor fastening devices shall provide electrical connection to the conductive part and may preferably be screw (bolt) or spring clamps.

[0179] Screw clamps securely connect conductors using bolts and washers that are secured in a threaded hole in the conductive part and clamp the conductor, ensuring a contact connection. Spring clamps use a flat leaf spring for securing the wires and a conductive busbar common to the conductor line.

[0180] For the insulating part of the UES, polymeric materials such as polyethylene and polypropylene are often used. However, in preferred embodiments, it is preferable to use halogen-containing polymeric materials, in particular chlorine-containing polymers, for example, vinyl chloride copolymers, namely: copolymer C-15 (copolymer of vinyl chloride and vinyl acetate), copolymer VHVD-40 (copolymer of vinyl chloride and vinylidene chloride), polyvinyl chloride (PVC), cast PVC, as well as polyvinylidene fluoride PVDF, fluoroplastic M-40, as well as polyesters with the addition of 6.5% hexabromocyclododecane or polyesters modified with 15% trichloroisopropyl phosphate.

[0181] Ceramic materials, primarily porcelain, can also be used. Porcelain tiles, terracotta, earthenware, and other ceramics can also be used in some applications. Composite materials, primarily textolite, can also be used. In certain cases, fiberglass, carbon fiber reinforced plastics, cermets, and other composite materials can be used.

[0182] The materials of the insulating part must have sufficient strength, fire resistance and have a dielectric strength of at least 3 kV / mm, preferably at least 5 kV / mm, and a thermal conductivity coefficient of at least 0.1 W / (m*K).

[0183] Location of temperature-sensitive elements on the UES

[0184] The TE may be applied, in particular, to the conductive part or to the insulating part. The preferred location is on the conductive part, preferably in a recess made therein.

[0185] Regardless of the location of the TE, it is preferable that the distance from the conductor attachment point to the nearest boundary of the TE does not exceed 10 mm, and preferably no more than 5 mm. The number of TEs is not upper-limited and depends on the practical task being accomplished using the specified device (equipment type, required step size for determining overheating temperature, surface area being tested for overheating, etc.).

[0186] In preferred embodiments, at least one group of TE is arranged in such a way as to provide the possibility of comparing the temperature of greatest heating of various contact connections (Fig. 10b).

[0187] In addition to a TE with an irreversible color transition, the device may include at least one temperature-sensitive material whose color transition is reversible upon reaching the appropriate threshold temperature. The reversible temperature-sensitive material may be incorporated into the at least one TE or may be applied directly to the UES.

[0188] The application of TE into specially created recesses on the surface of the UES elements was discussed earlier, in the section “General technology for manufacturing the device.”

[0189] When manufacturing the device, it is preferable to use a protective layer or polymer varnish that is transparent to at least some visible light. This layer protects the FC and the device itself from external environmental influences, humidity, UV radiation, and mechanical damage, thereby increasing the device's service life. The protective layer material is preferably selected from transparent elastic polymers, preferably halogen-containing polymers, in particular polyvinyl chloride, and most preferably cast polyvinyl chloride. Flexible elastic polymer films made of polyvinyl chloride, polyurethane, polyurea, and other polymers are preferred as protective layer materials.

[0190] The protective layer (if present) may have reflective or luminescent properties and may be colored to meet the requirements for marking cable phases, wiring harnesses, and other electrical equipment components. Information including threshold temperature values, the device's shelf life, and other data may be applied to its surface. In one embodiment, the inner surface of the protective layer may include multiple support elements (SEs), between which at least a portion of the temperature-sensitive material is located.

[0191] It is worth noting that the use of a protective layer also prevents the heat-sensitive material from flowing during the phase transition.

[0192] The TE may be a heat-sensitive composition applied directly to the surface of the UES element.

[0193] Also, the TE may include a dielectric material that is glued to the surface of the UES elements by means of an adhesive layer of constant tack, and at least one substance or mixture of substances having a melting temperature near the operating temperature of the TE.

[0194] In certain cases, the TE can be attached to a metal conductive part using a dielectric material. In this case, the dielectric material can be adhesives, particularly those based on acrylic, polyurethane, rubber, silicone, and PVC polymers. Polymer films can also serve as polymeric materials.

[0195] In all cases, it is preferable for the dielectric material to be elastic and flexible to enable adhesion to surfaces with complex geometries. Halogen-containing polymeric materials are preferably used as such materials, without limitation, in particular chlorine-containing polymers, such as vinyl chloride copolymers, namely: copolymer C-15 (copolymer of vinyl chloride and vinyl acetate), copolymer VHVD-40 (copolymer of vinyl chloride and vinylidene chloride), polyvinyl chloride (PVC), cast PVC, polyvinylidene fluoride PVDF, fluoroplastic M-40, as well as polyesters with the addition of 6.5% hexabromocyclododecane or polyesters modified with 15% trichloroisopropyl phosphate. Halogen-containing materials have low flammability. When selecting a dielectric material, its melting or decomposition temperature must be taken into account, which must be higher than the maximum response temperature of the thermal indicator.

[0196] It is also important to note that to further enhance operational safety, the TE device must have a dielectric strength of at least 5 kV / mm, which is facilitated by the use of a halogen-containing dielectric material. If the dielectric material is a polymer film or if the TE has a layered structure, the dielectric material can be back-coated with a permanent adhesive to ensure reliable adhesion to the surface of the UES elements. Adhesives based on acrylic, polyurethane, rubber, silicone, and PVC polymers can be used as permanent adhesives. The preferred adhesion of the adhesive layer to stainless steel, measured using the FINAT TM1 method after 24 hours, is at least 5 N / 25 mm.

[0197] To ensure the proper response speed of the TE, it is preferable to use a dielectric material with a thickness not exceeding 100 µm, most preferably not more than 50 µm.

[0198] In preferred embodiments, the dielectric material in the TE region is colored black to provide contrast in the color transition when the TE is triggered.

[0199] The dielectric material may have reflective or luminescent properties to increase the visibility of both the TE itself and the fact of its operation to improve the safety of equipment operation.

[0200] In certain cases, the surface of the dielectric material, or part of it, can be painted in accordance with the requirements for marking cable phases, installation wires, harnesses, and other electrical equipment components. The color of the dielectric material can be initially selected in accordance with GOST 28763-90, which establishes, among other things, color coding in electrical engineering. To enhance the contrast of the color transition, the dielectric material in the TE zone can be painted. Information, including threshold temperature values, the TE shelf life, and other data, can also be applied to the surface of the dielectric material.

[0201] In one embodiment, a dielectric material may be used that includes multiple support elements (SEs) between which at least a portion of the heat-sensitive material is located.

[0202] Manufacturing of temperature-sensitive elements

[0203] The claimed utility model may utilize various TEs whose operating principle is based on an irreversible change in appearance upon reaching a certain threshold temperature. It is preferable to use a single TE within a single UES; however, if necessary, TEs with different operating principles may be used. The preferred method is to use TEs whose temperature-sensitive components operate by changing their appearance upon melting, specifically by changing their transparency.

[0204] In certain cases, the change in appearance of at least one TE upon reaching the appropriate threshold temperature is associated with increased transparency, achieved by melting the substance or group of substances comprising the TE. When such TEs are activated, the color of the device portion or dielectric material (if any) located beneath them becomes apparent. If the TE is applied to a dielectric material (film), the activation of each TE may result in the same or different color transitions, depending on the color of the dielectric material beneath the respective TE. Preferably, the dielectric material beneath all TEs is colored black. In this case, all TEs are preferably white in their initial state, thereby ensuring a visually observable "white-to-black" transition upon activation.

[0205] At least one TE may include: a gas-filled hot-melt material (GFTM), preferably, the proportion of the gas phase in which is at least 10 vol.%; an absorbent material; support elements; at least one solid organic substance with a molecular weight of less than 2 kDa; at least one solid organic substance containing a structural fragment C n H(2n+i), where n is greater than or equal to 5, and is preferably selected from the group consisting of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 12; salts of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 5; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C n H(2n+i) with n greater than or equal to 5; amides of fatty aliphatic acids containing structural fragments C nH(2n+i) with n greater than or equal to 5; anhydrides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 10; fatty aliphatic alcohols containing structural fragments C n H(2n+i) with n greater than or equal to 14; fatty aliphatic amines containing structural fragments C n H(2n+i) with n greater than or equal to 17; nitriles of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 19.

[0206] In particular embodiments, the solid organic substance / a TE is, without limitation, selected from the group consisting of: yttrium caproate, yttrium behenate, yttrium undecanoate, yttrium laurate, yttrium tridecanelaurate, yttrium tridecanepentadecanate, yttrium tridecanoate, yttrium pentadecanoate, yttrium palmitate, ytterbium caprylate, lanthanum palmitate, lanthanum nonadecynate, lanthanum caproate, erbium undecanate, zinc nonadecanoate, zinc palmitate, zinc caproate, zinc myristicate, zinc stearate, cadmium laurate, cadmium laurinmyristate, lead caproate, lead stearate, lead laurate, lead laurinmyristate, stearate copper, calcium stearate, lithium stearate, stearic acid, lauric acid, docosanoic acid, eicosanoic acid, crotonic acid, arachidic acid, myristic acid, palmitic acid, adipic acid, octanoic acid, capric acid, tricosanic acid, tetratriacontanoic acid, 2,3-dimethylnonanoic acid, brassidic acid,2-methyl-2-dodecenoic acid, eleostearic acid, behenolic acid, behenic acid, oleamide, stearamide, lauramide, erucylamide, capric amide, myristic amide, caprylic amide, palmitic anilide, salicylic anilide, beta-naphthylamide caproic acid, enanthic phenylhydrazide, hexylamide, octacosylamide, N-methylheptacosylamide, salicylamide, hexadecanol, ecucamide, 1-docosonol, trilaurin, tricose amine, dioctadecylamine, H>4-dimethyloctylamine, dioctylphosphinic acid, tritriacontane, tetracosane, stearyl alcohol, cetyl alcohol, chloride stearic anhydride, palmitic anhydride, stearic and acetic anhydride, lauric anhydride or mixtures thereof with a melting point that differs from the threshold temperature by no more than 5 °C.,

[0207] When using a gas-fuel mixture (GPM) in at least one fuel cell, it is preferable that upon reaching the appropriate threshold temperature, the volume fraction of gas within the GPM decreases by at least a factor of two. This ensures that the change in transparency of the GPM is irreversible when the appropriate threshold temperature is exceeded.

[0208] The use of at least one fuel cell, including a gas-filled thermocouple (GFT) with a gas content of at least 10% by volume, also extends the service life of the fuel cell and improves the reliability of overheating detection by preventing the aggregation of solid organic matter through the gas phase. Furthermore, the higher the gas content in the GFT, the higher the initial refractive index, the more pronounced the change in appearance due to a significant reduction in refractive index when the corresponding threshold temperature is exceeded, and the greater the separation of the gas and other phases after the GFT is triggered. This eliminates the possibility of the GFT returning to its original gas-filled state when the triggered fuel cell is exposed to low temperatures and temperature fluctuations.When using a heat-sensitive material whose action is based on the melting of the active substance, and especially a thermally sensitive material (HTSM), the TE changes appearance only in the area heated above the corresponding threshold temperature, while maintaining the original appearance of other areas of the TE whose temperature did not exceed the corresponding threshold temperature. This allows for comparison of the temperatures of contact joints when a single TE thermally controls multiple contact joints.

[0209] The process of manufacturing a fuel cell including a gas turbine engine is described in detail in a number of the authors' patents, in particular, in patent RU 2800396 C1, published on July 21, 2023, and can be used to create a fuel cell for the claimed utility model.

[0210] To produce at least one HTPM, the solid organic substance is ground in a ball mill to a particle size of 2-3 µm. A liquid phase consisting of water or an organic solvent with a boiling point below 180°C is added, and the resulting suspension is mixed, preferably with periodic dispersion of the mixture under air access until the mixture reaches a constant density. The liquid phase is preferably water or an organic solvent in which the solubility of the solid organic substance of the HTPM does not exceed 100 g / kg.

[0211] In preferred embodiments of the utility model, the liquid phase is added in an amount of at least 50 wt.%, most preferably from 50 wt.% to 90 wt.%.

[0212] The difference in density between the liquid phase and the solid organic matter is preferably less than 0.2 g / cm 3. For this purpose, the liquid phase can be selected without limitation from the group consisting of isopropanol, water, methanol, 1-propanol, isobutanol, ethylene glycol monomethyl ether, 1-butanol, acetonitrile, acetic acid, hexane, heptane, octane, nonane, 1,1,1-trifluoroethanol, 1, 1,1, 3,3,3-hexafluoroisopropanol, [, 1-dimethylformamide, toluene, xylene, ethanol, butyl acetate, acetone and mixtures thereof. The resulting suspension or paste is applied to the selected part of the device or to the film (if any) and / or the protective layer (if any) and / or the absorbent material (if any) and dried under the action of dry air, temperature or vacuum.

[0213] This method enables the production of a gas-phase thermal media (GPM) comprising a solid organic substance, preferably in the form of particles with uniformly distributed gas-filled voids. Depending on the nature of the solid organic substance, the resulting particles may preferably be grains, crystals, fibers, flakes, or conglomerates thereof. In certain cases, at least one GPM additionally comprises a polymeric binder that is transparent to at least some visible light. In some embodiments, the binder ensures adhesion of the GPM to a selected portion of the device, a film (if present), or an absorbent material (if present). In this case, the ground solid organic substance is suspended in a solution of a binder that is transparent to at least some visible light in a solvent with a boiling point below 150°C.In preferred embodiments of the utility model, to ensure the glazing effect of the solid organic substance, the binder is present in the resulting GTPM in an amount of 1-30 wt.%.

[0214] The transparent polymer binder may be selected without limitation from the group consisting of phenol-formaldehyde resin, butyl methacrylate resin, melamine-formaldehyde resin, polyvinyl butyral, polybutyl methacrylate, polyisobutyl methacrylate, polybutyl acrylate, phenoxy resin, polystyrene-acrylic emulsion, polyolefin, polystyrene, polyacrylate, polyethersulfone, polyethylene, polypropylene, polystyrene, polyvinylidene fluoride, polytetrafluoroethylene, polyethersulfone, polyisoprene, polypropylene, polybutadiene, polyisobutylene, polyvinyl acetate, polymethacrylate, ethyl cellulose, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polycaprolactone, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resins, polyvinylidene fluoride, polyester, polyester resins, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, nitrocellulose, carboxymethyl cellulose, gelatin, agar-agar, casein, gum arabic, polyvinyl alcohol, polyethylene oxide or mixtures thereof,but not limited to them.,

[0215] At least one TE is selected in such a way that upon reaching the corresponding threshold temperature in the range of no more than 5 °C, preferably no more than 2 °C, the response speed is no more than 5 seconds, preferably no more than 2 seconds.

[0216] In various embodiments, the TE is selected in such a way that the threshold temperatures can be selected from a range of 50 to 210 °C. In this case, the numerical values ​​of the threshold temperatures of the TE can be selected, in particular, from the group of 50 °C, 55 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C, 190 °C, 200 °C, 210 °C.

[0217] For a device containing three different TEs (TE1, TE2, TE3), the threshold temperatures may be 50 °C, 55 °C, 60 °C, or 50 °C, 60 °C, 70 °C, or 50 °C, 70 °C, 80 °C, or 60 °C, 70 °C, 80 °C, or 60 °C, 80 °C, 100 °C, or 60 °C, 90 °C, 110 °C, or 70 °C, 80 °C, 90 °C, or 70 °C, 90 °C, 110 °C, or 70 °C, 100 °C, 120 °C, or 70 °C, 110 °C, 130 °C, or 80 °C, 90 °C, 100 °C, or 80 °C, 120 °C, 140 °C, or 80 °C, 120 °C, 150 °C, or 90 °C, 100 °C, 110 °C, or 90 °C, 110 °C, 130 °C, or 100 °C, 120 °C, 140 °C.

[0218] For a device containing four different TE (TE1, TE2, TE3, TED), the threshold temperatures may be 50 °C, 55 °C, 60 °C, 70 °C, or 50 °C, 60 °C, 70 °C, 80 °C, or 50 °C, 70 °C, 90 °C, 110 °C, or 60 °C, 70 °C, 80 °C, 90 °C, or 60 °C, 70 °C, 80 °C, 100 °C, or 60 °C, 80 °C, 90 °C, 110 °C, or 70 °C, 80 °C, 90 °C, 100 °C, or 70 °C, 90 °C, 100 °C, 120 °C, or 70 °C, 90 °C, 110 °C, 130 °C, or 80 °C, 90 °C, 100 °C, 110 °C, or 80 °C, 100 °C, 120 °C, 140 °C, or 80 °C, 100 °C, 120 °C, 150 °C.

[0219] In specific implementation cases of the utility model, one or more TEs may contain supporting elements uniformly distributed within the heat-sensitive material, which are added to it during its manufacture. Supporting elements may be made of a material with a melting point higher than the TE's response temperature. Polymeric materials, particularly halogen-containing polymers such as polyvinyl chloride and cast polyvinyl chloride, as well as glass, ceramics, metals, non-metals, and products based on them, such as meshes, fibers, microspheres, woven or non-woven materials possessing the above-mentioned characteristics, can be used as supporting elements.

[0220] In specific implementation cases of the utility model, one or more TEs may include an absorbent material (AM) that absorbs the molten hot-melt material during its activation. The use of an AM provides additional enhancement of the technical result due to the irreversibility of the TE's activation. Furthermore, the AM can perform the functions of the TE described above.

[0221] In certain cases, the EM is made of porous or absorbent materials, preferably microporous materials. EM may be selected without limitation from paper, microcellulose, wool, silk, felt, cotton, linen, molecular sieves, zeolites, silica gel, aerosil, microspheres, and ceramics. Microporous materials with a pore diameter of no more than 2 µm are most preferred. The EM may be colored. In this case, the color of the EM will appear upon activation. Alternatively, the EM may become transparent upon absorption of a melt (silica gel, aerosil). In this case, upon activation of the TE, the color of the device element in the area where the TE is applied or the color of the base will appear.

[0222] Applying Temperature-Sensitive Elements: To manufacture a device in which the thermoelement is applied directly to the surface of a part of the device, the area where the thermoelement should not be located is covered with a protective polymer film. The thermoelement is applied using a selected method, depending on the type of thermosensitive material used. The film is then removed, and the process is repeated for applying the remaining thermoelements (if more than one thermoelement is used). The shape and size of the thermoelements may be the same or different, depending on the device requirements.

[0223] After applying all the TEs, in some embodiments of the utility model, the device, at least in the area of ​​the TE, is covered with a protective layer that is transparent to at least part of the visible light.

[0224] When using a dielectric material or absorbent material, it is preferable to first apply at least one temperature-sensitive material to these materials, and then, in the second step, place the resulting TE on the surface of the UES, particularly using a permanently tacky adhesive layer. However, the reverse sequence can also be used. The protective layer can be applied either before or after the TE is placed on the surface of the UES.

[0225] How a temperature indicator works

[0226] The device, according to the claimed utility model, operates as follows. Wires are inserted into the conductor mounting holes using a conductor securing device. In their initial state, all FCs are the same color, predominantly white.

[0227] Then the operating voltage is connected to the contacts of the terminal block. Until the moment the entire surface of the device or individual conductor fastening units are heated to the threshold value of the lowest temperature TE (Ti), the original appearance of the device is preserved. When one individual conductor fastening unit is heated above the threshold temperature of the lowest temperature TE (Ti), an irreversible change in the appearance of this TE or its part occurs in the area of ​​this contact connection. At the same time, other TEs with threshold temperatures Tg . Tp > Tb. A further increase in the temperature of one individual conductor fastening unit, on which a fragment of the thermal indicator is located, to a temperature Tg . Tp leads to sequential irreversible operation of the corresponding TEs (or their part) with threshold temperatures Tg . Tp. Moreover, if the maximum temperature of one individual conductor fastening unit is lower than at least one of the threshold temperatures T п, the corresponding TEs will retain their original appearance. Upon subsequent cooling, the surfaces of the areas with the activated TEs retain their appearance, preventing the entire temperature indicator from returning to its original state. This ensures the ability to visually record temperature exceeding the threshold, both at the moment of overheating and after a long period of time.

[0228] Thus, the UES according to the claimed utility model can be used to monitor the temperature of conductor connection assemblies. Visual inspection of such terminal blocks can reliably and accurately record the occurrence of elevated temperatures in all or any individual electrical connections, improving the safety of electrical equipment operation by simplifying the interpretation of temperature indicator monitoring results without compromising their informative value.

[0229] Below are presented preferred embodiments of the claimed utility model, which are illustrative and in no way limit the scope of the requested legal protection.

[0230] Example 1.

[0231] Manufacturing the UES. A busbar is manufactured (similar to Fig. 1) with 14 conductor-mounting devices. The conductive portion of the busbar is 97 mm long and 10 mm wide. The conductor-mounting devices are positioned closer to one side, thereby allowing the TE to be positioned along the mounting points of all conductors (similar to Fig. 16).

[0232] Preparation of a heat-sensitive material. Eicosanoic acid, with a phase transition temperature of 70°C, is used as the heat-sensitive material. A mixture of methanol and ethylene glycol methyl ether (50 / 50 vol%) is used as the liquid phase. 100 g of the solid organic substance is ground to a particle size of 2-3 µm. 200 g of the liquid phase is added and mixed, ensuring periodic dispersion of the mixture with access to air, until the mixture reaches a constant density. The resulting suspension is applied immediately after preparation.

[0233] Manufacturing of the thermoelectric cell. The dielectric material is a 4 x 93 mm, 0.05 mm thick, reflective PVC film coated on the back with permanent adhesive. The area to be coated with the temperature-sensitive material is painted black using solvent dyes, and information elements displaying the threshold temperature are added. The resulting blank is placed on the prepared area of ​​the conductive part, 1 mm from the edge of the screw head.

[0234] A suspension of heat-sensitive material is applied to the front surface of the dielectric material using silk-screen printing in five layers. After each layer is applied, it is dried for 24 hours at room temperature. The resulting TE is initially white, with an average thickness of 0.075 mm.

[0235] The length of the resulting heat-sensitive zone is 89 mm, the width is 2 mm, the total area is 178 mm 2 The distance from the edge of the screw head to the heat-sensitive zone is 2 mm.

[0236] On top of the TE, a smooth, transparent, colorless protective layer made of 0.025 mm thick PVC is applied. The dielectric material and the protective layer are bonded using the adhesive properties of the adhesive composition under a reduced pressure of 26.7 kPa (200 mm Hg).

[0237] The bus is equipped with a DIN rail mount made of insulating polymer material.

[0238] Triggering of the TE UES.

[0239] The resulting resistivity is checked for conductor attachment reliability. Next, the conductive surface locally in the area of ​​the contact connection of one of the conductors is heated in a controlled manner at a rate of 5°C / min to a temperature of 70°C with a specified accuracy. Heating is stopped, and the activation of the TE in the area of ​​this contact connection is visually recorded by a change in appearance, specifically by an increase in the transparency of the heat-sensitive material and the appearance of the dielectric material (similar to Fig. XB). The time it takes for the TE appearance to change is 0.9 seconds. After the device cools to room temperature, visually confirm that the TE does not return to its original appearance.

[0240] Example 2.

[0241] Manufacturing of the UES. A spring-loaded terminal block (similar to Fig. 2b) is manufactured, featuring three spring-loaded fixtures for securing the conductors. The housing is 30 mm long and 25 mm wide.

[0242] Preparation of a heat-sensitive material. The following substances are used to prepare the heat-sensitive material: dioctylphosphinic acid with a phase transition temperature of 80°C, didecylphosphinic acid with a phase transition temperature of 90°C, and lanthanum nonadecynate with a phase transition temperature of 110°C. Acetonitrile is used as the liquid phase. A 100-gram solid organic substance is ground to a particle size of 2-3 µm. 200 grams of the liquid phase are added and mixed, ensuring periodic dispersion of the mixture with access to air, until the mixture has a constant density. The resulting suspension is applied immediately after preparation.

[0243] Manufacturing of the TE. Three pieces of black M-40 fluoroplastic film, 25 mm by 5 mm in size and 0.07 mm thick, coated on the back with permanent adhesive, are used as the dielectric material. Information elements displaying the numerical values ​​of the threshold temperatures are applied to the area where the temperature-sensitive materials will be applied using solvent dyes. The resulting blank is placed on the housing of the spring terminal block.

[0244] A suspension of the first temperature-sensitive material is applied to the front surface of the first dielectric fragment using silk-screen printing in five layers. After each layer is applied, it is dried for 24 hours at room temperature. The process is repeated for the second and third temperature-sensitive materials, placing them on the corresponding film fragments. The resulting thermoelectric cells are initially white, and their average thickness is 0.075 mm.

[0245] The length of the obtained temperature-sensitive zones is 25 mm, the width is 5 mm, the total area is 125 mm 2 The distance from the conductor securing device to each heat-sensitive zone is 5 mm.

[0246] Triggering of the TE UES.

[0247] The resulting resistivity is checked for the reliability of the conductor attachment. Next, the conductive surface in the area of ​​the contact connection of all three conductors is heated in a controlled manner at a rate of 5°C / min to a temperature of 90°C with a specified accuracy. Heating is stopped, and the activation of the corresponding zones of the TE located in the area of ​​these contact connections is visually recorded by a change in appearance, specifically by an increase in the transparency of the heat-sensitive material and the appearance of the color of the dielectric material (similar to Fig. 2c). The original appearance of the TE, which has the maximum threshold temperature, is maintained. The time required for the change in appearance of the TE is 0.7-0.9 seconds. After the device cools to room temperature, visually confirm that the TE does not return to its original appearance.

[0248] Example 3. Manufacturing a UES. A spring terminal block (similar to Fig. 2g) is manufactured with three spring-loaded conductor securing devices. The terminal block body is 30 mm long and 25 mm wide. On the terminal block body, adjacent to each conductor securing device, recesses measuring 7 x 20 mm and 1 mm deep are machined at a distance of 2 mm.

[0249] Preparation of a heat-sensitive material. Yttrium behenate, with a phase transition temperature of 90°C, is used as the heat-sensitive material, and ethylene glycol monomethyl ether is used as the liquid phase. 100 g of the solid organic substance is ground to a particle size of 2-3 µm. 200 g of the liquid phase is added, and the mixture is mixed, ensuring periodic dispersion with access to air, until a constant density is achieved. The resulting suspension is applied immediately after preparation.

[0250] Manufacturing of the TE. Information elements displaying the numerical value of the threshold temperature are applied to the recesses using solvent dyes. A suspension of temperature-sensitive material is then applied in four layers. After each layer is applied, the TE is dried for 24 hours at room temperature. The resulting TE is coated with a colorless protective layer made of 0.025 mm thick PVC, bonding the protective layer to the socket body using the adhesive properties of the adhesive layer located on the back of the protective layer.

[0251] The obtained FCs in their initial state are white in color, their average thickness is 0.52 mm.

[0252] The size of each TE zone corresponds to the size of the recesses and is 7*20 mm, the total area of ​​each zone is 140 mm 2 The distance from the conductor fastening device to the heat-sensitive zone is 2 mm.

[0253] Triggering of the TE UES.

[0254] The resulting resistivity is checked for conductor attachment reliability. Next, the conductive surface in the area of ​​the contact joint of one of the conductors is heated in a controlled manner at a rate of 5°C / min to a temperature of 90°C with a specified accuracy. Heating is stopped, and the activation of the corresponding zone of the TE located in the area of ​​this contact joint is visually recorded by a change in appearance, specifically by an increase in the transparency of the heat-sensitive material and the appearance of the color of the dielectric material (similar to Fig. 2d). The original appearance of the other TEs, the contact joints near which were not heated to the threshold temperature, is maintained. The time required for the TE appearance to change is 0.7-0.9 seconds. After the device cools to room temperature, visually confirm that the TE does not return to its original appearance.

[0255] Example 4.

[0256] Manufacturing the UES. A screw terminal block (similar to Fig. 5a) is manufactured, featuring two screw-type fastening devices for securing the conductors. The distance between the fastening devices is 15 mm to allow the TE to be positioned as a single zone adjacent to the conductor fastening devices.

[0257] Preparation of a heat-sensitive material. Palmitic acid, which has a phase transition temperature of 60°C, is used as the heat-sensitive material, and a 3% polycarbonate solution in isopropanol is used as the liquid phase. 100 g of the solid organic material is ground to a particle size of 2-3 µm. 200 g of the liquid phase is added and mixed, ensuring periodic dispersion of the mixture with access to air, until the mixture reaches a constant density. The resulting suspension is applied immediately after preparation.

[0258] Manufacturing of the thermoelectric cell. A suspension of the temperature-sensitive material is applied in three layers to a 100-micron-thick felt backing made of absorbent material using silk-screen printing. After each layer is applied, it is dried for 24 hours at room temperature. The resulting thermoelectric cell is secured to the conductive portion of a screw terminal block between the conductor clamping devices.

[0259] The TE zone has dimensions of 9 mm, width 5 mm, the total area of ​​each zone is 45 mm 2 The distance from the edge of the screw heads to the heat-sensitive zone is 3 mm.

[0260] Triggering of the TE UES.

[0261] The resulting resistivity is checked for the reliability of the conductor attachment. Next, the conductive surface locally in the area of ​​the contact joint of one of the conductors is heated in a controlled manner at a rate of 5°C / min to a temperature of 60°C with a specified accuracy. Heating is stopped, and the activation of the corresponding zone of the TE located in the area of ​​this contact joint is visually recorded by a change in appearance, namely, an increase in the transparency of the heat-sensitive material (similar to Fig. 5b). In this case, the original appearance of the zone of the TE where the contact joint near it was not heated to the threshold temperature is predominantly preserved. The time required for the change in the TE's appearance to occur is 0.7 seconds. After the device cools to room temperature, it is visually recorded that the TE's original appearance does not return.

[0262] Example 5.

[0263] Manufacturing of the UES. A busbar is manufactured with 14 conductor securing devices. The conductive portion is 97 mm long and 10 mm wide. The conductor securing devices are positioned closer to one side, thereby allowing the TE to be positioned along the securing devices for all conductors (a partial image of this busbar is shown in Fig. 9a). The conductor securing devices are covered with a protective shield.

[0264] Manufacturing of the TE. A 5 x 3 mm area of ​​the protective shield near each conductor connection is coated with Tempilaq reversible, pigmented green thermal paint with a color change temperature of 30°C. A chemical compound with a response temperature of 90°C is used as the irreversible heat-sensitive material. The resulting TE is initially white, and its average thickness is 0.06 mm.

[0265] The size of the zone with reversible thermal composition is 5*3 mm, the total area is 15 mm 2 The size of the zone with irreversible composition is 4.5 * 2.5 mm, the total area is 11.25 mm 2 The distance from the edge of the screw head to the heat-sensitive zone is 3 mm. The top of the thermoelectric element is coated with a smooth, transparent, colorless protective varnish 0.015 mm thick.

[0266] Triggering of the TE UES.

[0267] The resulting resistivity is checked for the reliability of the conductor attachment. Next, the conductive surface locally in the area of ​​the contact connection of the three conductors is heated in a controlled manner at a rate of 5°C / min to a temperature of 90°C with the specified accuracy. Heating is stopped, and the activation of the corresponding zones of the TE located in the area of ​​these contact connections is visually recorded by a change in appearance, specifically, a color change from white to black. The time it takes for the TE to change appearance is 2.7 seconds. After the device cools to room temperature, it is visually recorded that the TE does not return to its original appearance. The conductive surface is then heated in a controlled manner at a rate of 5°C / min to a temperature of 115°C with the specified accuracy, and the activation of the thermal paint is recorded by a color change from green to red (Fig. 9b).After cooling the device to room temperature, the preservation of the black color of the triggered zones with irreversible heat-sensitive materials and the return of the color of the reversible thermal paint to its original green color were visually recorded (Fig. 9c).

[0268] Example 6.

[0269] Manufacturing of the UES. A busbar is manufactured with 14 conductor-mounting devices. The conductive portion of the busbar is 97 mm long and 10 mm wide. The conductor-mounting devices are positioned closer to one side, thereby allowing the TE to be positioned along the mounting points of all conductors (this busbar is partially shown in Fig. 10a).

[0270] Preparation of a heat-sensitive material. Stearic acid, with a phase transition temperature of 70°C, and dotriacontan-1-ol, with a phase transition temperature of 90°C, are used as the substances for the preparation of heat-sensitive materials. A mixture of ethanol and water (50 / 50 vol%) is used as the liquid phase. A solid organic substance weighing 100 g is ground to a particle size of 2-3 µm. 200 g of the liquid phase is added and mixed, ensuring periodic dispersion of the mixture with access to air, until the mixture reaches a constant density. The resulting suspension is used for application immediately after preparation.

[0271] FC manufacturing. The conductive area near each conductor connection is coated with black solvent-based dyes, indicating the threshold temperature. Suspensions of temperature-sensitive materials are then applied sequentially in four layers. After each layer, the cells are dried for 24 hours at room temperature. The resulting FCs are initially white, and their average thickness is 0.08 mm.

[0272] The size of each zone with irreversible composition is 2*1 mm, the total area is 2 mm 2 The distance from the edge of the screw head to the heat-sensitive zone is 1 mm.

[0273] Triggering of the TE UES.

[0274] The resulting resistivity is checked for the reliability of the conductor attachment. Next, the conductive surface locally in the area of ​​the contact joint of the three conductors is heated at a controlled rate of 5°C / min to a temperature of 70°C with a specified accuracy. Heating is stopped, and the activation of the corresponding zones of the TE located in the area of ​​these contact joints is visually recorded by a change in appearance, specifically a color change from white to black. The time it takes for the TE appearance to change is 2.7 seconds. After the device cools to room temperature, it is visually recorded that the TE does not return to its original appearance.The conductive surface locally in the area of ​​the contact connection of one of the conductors was then heated in a controlled manner at a rate of 5°C / min to a temperature of 90°C with a specified accuracy. The activation of the corresponding TE zone located in the area of ​​this contact connection was recorded by a change in appearance, specifically, a color change from white to black (Fig. 106). After cooling the device to room temperature, the black color of the activated zones with irreversible TE was visually observed.

[0275] Example 7.

[0276] Manufacturing of the UES. A busbar is manufactured with 12 conductor fastening devices, the conductive portion of which is 97 mm long and 10 mm wide. The conductor fastening devices are positioned closer to one side, thereby allowing the TE to be placed close to the conductor fastening devices (similar to Fig. 4a, b).

[0277] Preparation of a heat-sensitive material. The heat-sensitive material is prepared using dotriacontan-1-ol, which has a phase transition temperature of 90°C. A mixture of ethanol and water (50 / 50 vol%) is used as the liquid phase. 100 g of the solid organic substance is ground to a particle size of 2-3 µm. 200 g of the liquid phase is added and mixed, ensuring periodic dispersion of the mixture with access to air, until the mixture reaches a constant density. The resulting suspension is applied immediately after preparation.

[0278] Manufacturing of the TEs. The conductive area near each conductor connection is coated with black solvent-based dyes, indicating the threshold temperature. A suspension of temperature-sensitive materials is then applied in four layers. After each layer, the TEs are dried for 24 hours at room temperature. The resulting TEs are initially white, and their average thickness is 0.08 mm.

[0279] The size of each zone with irreversible composition is 2*1.5 mm, the total area is 3 mm 2 The distance from the edge of the screw head to the heat-sensitive zone is 0.8 mm.

[0280] Triggering of the TE UES.

[0281] The resulting resistivity is checked for the reliability of the conductor attachment. Next, the conductive surface locally in the area of ​​the contact connection of the three conductors is heated in a controlled manner at a rate of 5°C / min to a temperature of 90°C with a specified accuracy. Heating is stopped, and the activation of the corresponding TE zones located in the area of ​​these contact connections is visually recorded by a change in appearance, specifically a color change from white to black. The time it takes for the TE to change appearance is 1.2 seconds. After the device cools to room temperature, it is visually recorded that the TE does not return to its original appearance (similar to Fig. 4c). After the device cools to room temperature, the activated zones with irreversible TEs retain their black color.

Claims

Formula 1. A device for electrical connection (DEC) of two or more conductors, comprising a metal conductive part, an insulating part, and at least two devices for securing conductors electrically connected to the conductive part, characterized in that the DEC contains at least one temperature-sensitive element (TE) designed with the possibility of an irreversible change in appearance when heated above a corresponding threshold temperature.

2. The device according to item 1, configured to electrically connect wires.

3. The device according to item 1, designed with the possibility of use in distribution boards with voltage up to 1000 V.

4. The device according to claim 1, in which the TE has a layered structure including an adhesive layer of constant tack, a dielectric material, at least one substance or mixture of substances having a melting temperature near the operating temperature of the TE.

5. The device according to claim 1, in which at least one TE is designed with the possibility of changing its appearance when the device is heated, preferably when at least one contact connection of the device is heated, above a threshold temperature for no more than 5 seconds, and the accuracy of recording the excess of the threshold temperature is at least ±5 °C, preferably at least ±2 °C.

6. The device according to item 1, in which the TE has a dielectric strength of at least 5 kV / mm.

7. The device according to claim 1, wherein the service life of the fuel element is at least 5 years, preferably at least 10 years, most preferably at least 25 years.

8. The device according to claim 1, in which at least one TE is protected from external influences by a polymer varnish or protective film, preferably transparent to at least part of the visible light, preferably made from halogen-containing polymers, most preferably from polyvinyl chloride.

9. The device according to claim 1, in which the area of ​​at least one TE is at least 2 mm 2 , preferably 4-25 mm 2 , and the minimum distance from the edge of the TE to at least one device for fixing conductors does not exceed 5 mm.

10. The device according to claim 1, wherein the color of the TE in the initial state is predominantly white, and the color after operation is predominantly black.

11. The device according to claim 1, in which at least one TE is applied to the metal conductive part and, preferably, is located in a recess made on the metal conductive part.

12. The device according to claim 1, in which at least one TE is fixed to the metal conductive part using a dielectric material, preferably an adhesive, in particular an adhesive based on acrylic, polyurethane, rubber, silicone, PVC polymers, or using a dielectric material, preferably made from halogen-containing polymers, most preferably from polyvinyl chloride.

13. The device according to item 1, designed with the possibility of being secured to a DIN rail.

14. The device according to claim 1, in which the TE is applied to the insulating part of the device, preferably to the housing or protective screen.

15. The device according to item 1, in which the devices for fastening the conductors are made in the form of a screw connection, and the UES itself is a screw terminal block, a screw terminal, a neutral busbar, or a screw clamp.

16. The device according to item 1, in which the devices for fastening the conductors are made in the form of a spring connection, and the UES itself is a spring terminal block.

17. The device according to item 1, containing a fuel element according to one of the options: - at least one TE placed at the same distance from at least two devices for fixing conductors; - at least two TEs with the same threshold temperatures, each of which is placed near a corresponding device for securing the conductors; - at least one group of TEs, including at least two TEs with different threshold temperatures, wherein at least one group of TEs is located at the same distance from at least two devices for securing conductors; - at least two groups of TEs, including at least two TEs with different threshold temperatures, each of which is placed near a corresponding device for securing conductors.

18. The device according to claim 1, including at least one temperature-sensitive material designed to reversibly change color upon reaching a corresponding threshold temperature.

19. The device according to claim 1, characterized in that at least one TE has at least one property selected from the group of properties (1) - (5): (1) includes a gas-filled hot-melt material (GFTM), preferably, the proportion of the gas phase in which is at least 10 vol.%; (2) contains absorbent material; (3) contains supporting elements; (4) includes at least one solid organic substance with a molecular weight of less than 2 kDa; (5) includes at least one solid organic substance containing a structural fragment C n H(2n+i), where n is greater than or equal to 5, and is preferably selected from the group consisting of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 12; salts of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 5; alkanes containing at least 20 carbon atoms; dialkylphosphinic acids containing structural fragments C n H(2n+i) with n greater than or equal to 5; amides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 5; anhydrides of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 10; fatty aliphatic alcohols containing structural fragments C n H(2n+i) with n greater than or equal to 14; fatty aliphatic amines containing structural fragments C nH(2n+i) with n greater than or equal to 17; nitriles of fatty aliphatic acids containing structural fragments C n H(2n+i) with n greater than or equal to 19.

Images