electrical connection unit

Abstract

An electrical connection unit 100 for a refrigeration system includes a container 110 defining an interior for housing electrical circuitry, the container 110 having an exterior port 112 configured to couple with an external connector 190; a closure 120 movable relative to the container 110 between a closed configuration preventing access to the interior and an open configuration allowing access to the interior. The closure 120 has a locking portion 122 defining a connector opening 120 for receiving the connector 190, the closure 120 configured such that the closure 120 is prevented from being moved to the open configuration by interlocking engagement of the connector 190 with the closure 120. Related methods of coupling and decoupling the connector with the electrical connection unit are also disclosed.

Description

Technical Field

[0001] The present invention relates to an electrical connection unit for use with a power distribution system, and more particularly, but not exclusively, to an electrical connection unit configured to supply electrical power to a transport refrigeration system (TRU), the electrical connection unit including internal components that need to be accessed during installation, repair, reconfiguration and / or maintenance. Background Technology

[0002] A transport refrigeration unit (TRU) is known to include multiple loads and receive and / or distribute power from multiple power sources. The electrical system of a transport refrigeration unit is an example of an electrical system involving connections between one or more power sources and one or more loads.

[0003] For example, access to components of an electrical system may be required during manufacturing, commissioning, installation, and maintenance. For instance, during installation and / or maintenance, access may be necessary to reconfigure or replace components.

[0004] It is well known that electrical systems use hazardous voltage power supplies. Hazardous voltage can be defined as a voltage that would pose a significant health risk if a human operator (or animal) approaches or comes into contact with a circuit that conducts a hazardous voltage. The significant health risks posed by hazardous voltage may stem from the risk of electric shock or electrocution, and / or from the risk of arc flashes and / or arc impacts.

[0005] It is intended to prevent human operators (or other organisms, such as animals) from approaching or coming into contact with hazardous voltages or circuits during installation, repair, reconfiguration and / or maintenance.

[0006] For this purpose, it is known to use sensors and / or switches as part of a safety system. Such systems typically use mechanical switches or various types of electrical sensors to determine whether the interior of an electrical connection unit is being accessed by an operator. Examples of electrical sensors used for this purpose include induction coil switches and optical sensors. If it is determined that the interior of the electrical connection unit is being accessed by an operator, the safety system can disable or de-energize the hazardous voltage circuitry contained within the electrical connection unit. Summary of the Invention

[0007] According to a first aspect, an electrical connection unit for a refrigeration system is provided, the electrical connection unit comprising: a container defining an interior for housing circuitry, the container having an external port configured for engagement with an external connector; and a closure movable relative to the container between a closed configuration preventing access to the interior and an open configuration allowing access to the interior, wherein the closure has a locking portion defining a connector opening for receiving a connector; wherein the container and the closure are configured such that, when the closure is in the closed configuration, the connector opening aligns with the port to allow the connector to engage with the port through the connector opening to interlock with the closure; thereby, the interlocking engagement of the connector and the closure prevents the closure from being moved to the open configuration.

[0008] The interior of the container can be configured to contain or may contain hazardous circuitry.

[0009] The closure can move relative to the container between a closed position corresponding to a closed configuration and one or more open positions corresponding to an open configuration. The closure can have multiple possible open positions relative to the container, and in the open positions, the closure is configured to be in an open configuration relative to the container.

[0010] When the port is included in the container, the port may be connected to or can be connected to a dangerous voltage circuit.

[0011] The container and the closure can cooperate to limit a limited travel of the closure relative to the container between a closed configuration and an open configuration of the closure; wherein the closure and the container are configured such that, during the travel other than in the closed configuration, a locking portion of the closure at least partially covers the port to prevent the connector from engaging with the port when the closure is in the open configuration.

[0012] The closure can be attached to the container via a hinge.

[0013] The locking part can be configured to overlap one side of the container when in the closed configuration; and / or wherein the locking part depends on the cover of the closure in the form of a flange.

[0014] The port may be provided with a housing configured to prevent the electrical contacts in the port from being exposed.

[0015] The container may include a hazardous voltage interlock circuit that is electrically connected to the port and configured to selectively energize or de-energize the hazardous voltage circuit.

[0016] The dangerous voltage interlock circuit can be configured such that when an electrical control signal is provided to the dangerous voltage interlock circuit, the dangerous voltage circuit is energized by turning on the electrical or electronic switch (such as a transistor, relay, thyristor, contactor, etc.) of the dangerous voltage circuit.

[0017] The dangerous voltage interlock circuit can be configured to energize or de-energize the dangerous voltage circuit by sending a signal to the dangerous voltage source to connect it to the electrical connection unit or isolate it from the electrical connection unit, depending on the connection status of the external connector.

[0018] The hazardous voltage interlock circuit may also include a discharge circuit configured to completely discharge any remaining stored charge in the hazardous voltage circuit when the circuit is de-energized. The discharge circuit may be an active discharge circuit or a passive discharge circuit.

[0019] Dangerous voltage interlock circuits can be part of non-dangerous voltage circuits.

[0020] The port may be equipped with a sensing device configured to de-energize dangerous voltage circuits when an external connector is not connected to the port.

[0021] The electrical connection unit may include two external ports, each configured to connect to an external connector, wherein, for each port: a locking portion of a corresponding closure defines a connector opening for receiving the corresponding connector; the container and the closure are configured such that, when the closure is in the closed position, the corresponding connector opening aligns with the port to allow the corresponding connector to engage with the port through the connector opening for interlocking with the closure; thereby, the interlocking engagement of the connector and the closure prevents the closure from being moved to an open configuration. Each port and the associated locking portion may have any of the features described above with respect to the first aspect of the invention. The locking portion may be located on the opposite side of the container.

[0022] According to a second aspect, an assembly is provided comprising an electrical connection unit according to the first aspect, and a connector configured to engage with an external port or at least one of the external ports. The electrical connection unit may have any of the features described above with respect to the first aspect. The connector and the corresponding connector opening may have corresponding cross-sectional profiles.

[0023] According to a third aspect, a refrigeration system is provided, which includes an electrical connection unit according to the first aspect or a component according to the second aspect.

[0024] According to a fourth aspect, a method is provided, the method comprising: when the closure is in a closed position, engaging or disengaging a connector to a port in the electrical connection unit according to the first aspect if the electrical connection unit includes only one external port, or engaging or disengaging a connector to one of the ports in the electrical connection unit according to the first aspect if the electrical connection unit includes two external ports. Attached Figure Description

[0025] The invention will now be described by way of example only, with reference to the accompanying drawings, in which:

[0026] Figure 1A-1C A perspective view of the first exemplary electrical connection unit is shown;

[0027] Figure 2 A side view of an exemplary electrical connection unit in the closed position is shown;

[0028] Figure 3 A side view of an exemplary electrical connection unit in the open position is shown;

[0029] Figure 4 A side view of an exemplary electrical connection unit in multiple open positions is shown;

[0030] Figures 5A-5C A perspective view of the second exemplary electrical connection unit is shown;

[0031] Figures 6A-6B An exemplary dangerous voltage circuit is shown in both the energized and de-energized states;

[0032] Figure 7A This is a flowchart of a method for connecting a connector to the port of an electrical connection unit; and

[0033] Figure 7B This is a flowchart of a method for disconnecting the connector from the port of the electrical connection unit. Detailed Implementation

[0034] Figure 1A , 1B Figures 1C and 1C each show an electrical connection unit 100 and an external connector 190. The electrical connection unit 100 includes a container 110 and a closure 120. In this example, the container 110 is in the form of a rectangular pentagonal box with an open side (the container 110 may also be referred to as a housing), and the closure 120 is in the form of a cover or door configured to close the open side of the container 110, but different configurations may be possible in other examples. The container 110 defines an interior for housing circuitry (such as hazardous voltage circuitry) and is provided with an external port 112 configured to engage with the external connector 190. The term "external" is used to indicate that the port 112 (and the connector 190) is located outside the interior of the container for external connection to the connector 190. It should be understood that the port 112 is configured for internal connection with the contained circuitry.

[0035] The closure 120 is movable relative to the container 110 between a closed position (i.e., a closed configuration) that prevents access to the interior and multiple open positions that allow access to the container 110. For example, the closed configuration can be defined as engaging the closure with the container to provide Level 3 protection against solid foreign objects according to IEC standard 60529 (EN 60529) (i.e., IP3X). The open configuration can be defined as disengaging the closure from the container so that Level 3 protection against solid foreign objects according to IEC standard 60529 is no longer maintained; for example, the closure and container in the open configuration can provide any lower level (e.g., Level 2 or Level 1) or no level (Level 0) protection against solid foreign object ingress according to IEC standard 60529 (EN 60529). When the closure is in any open position, it is in the open configuration relative to the container 110. The closure 120 is movable relative to the container 110 throughout its entire stroke relative to the container. As will be described in detail below, the closure 120 can be moved from the closed position to the open position only when the external connector 190 is not connected to the external port 112 of the container 110.

[0036] Figure 1A A perspective view shows the electrical connection unit 100 in the closed position (closed configuration) and the external connector 190 separated from the external port 112. The closure has a locking portion 122 configured to interlock with the connector 190 when it is engaged with the port 112. In this particular example, the locking portion 122 hangs from the cover of the closure in the form of a flange generally parallel to the side of the container, but in other examples the locking portion may take other forms, for example, based on the port location. The locking portion 122 defines a connector opening 124 for receiving the connector 190 passing through it to connect and disconnect from the port 112. The container 110 and the closure 120 are configured such that when in the closed position (closed configuration), the connector 190 is engaged with the port 112. Figure 1A In the closed position, connector opening 124 is aligned with port 112, allowing connector 190 to engage with port 112 through connector opening 124 for interlocking with closure 120. For example, the port may define a connecting axis along which the connector is received, and when closure 120 is in the closed position, the connecting axis may extend through connector opening 124.

[0037] Figure 1BA perspective view of the electrical connection unit 100 in the closed position (closed configuration) is shown, wherein the external connector 190 is connected to the external port 112 of the container 110 via the connector opening 124 of the locking portion 122 of the closure 120. An interlocking engagement between the connector 190 and the locking portion 122 of the closure 120 prevents movement of the closure 120 from the closed position to the open position. The interlocking engagement keeps the closure 120 in the closed position (closed configuration) relative to the container 110.

[0038] Figure 1C A perspective view of the electrical connection unit 100 in the open position (open configuration) is shown. The external connector 190 is separated from the external port 112 of the container 110. With the connector 190 separated from the port 112, the closure can be opened relative to the container 110 from... Figure 1A The configuration shown is turned off. Figure 1C The open configuration shown allows for free movement. The closure 120 is not prevented from... Figure 1C The open position shown is moved to another open position among multiple open positions, and is not prevented from being moved to the closed position.

[0039] External port 112 is directly connected to or can be connected to circuitry located inside container 110. As will be discussed in further detail below, when external connector 190 is connected to external port 112, the circuit is energized. When energized, current flows through the circuit, posing a risk of electric shock if an operator approaches or touches the energized circuit. Furthermore, there is a risk of arc flash or arc impact in the presence of an operator associated with the circuit. On the other hand, when external connector 190 is not connected to external port 112, the circuit is de-energized. When de-energized, no current flows through the circuit, therefore posing no risk of electric shock to the operator.

[0040] The electrical connection unit 100 features a safety system that ensures access to the interior of the container is permitted only when the external connector 190 is disconnected from the external port 112 and subsequently moved from a closed position to an open position. Therefore, the electrical connection unit 100 reduces the likelihood of an operator approaching or contacting energized circuitry during, for example, installation, reconfiguration, repair, and / or maintenance. This significantly reduces the risk of electric shock to the operator. Furthermore, it significantly reduces the risk of arc flashes and / or arc impacts in the presence of an operator.

[0041] The interlocking engagement of the external connector 190 with the locking portion 122 of the enclosure 120 provides a reliable safety system based on mechanical interlocking, which is less susceptible to many of the possible failure modes of other previously conceived safety systems.

[0042] One possible failure mode associated with the previously conceived safety system is providing false negative results. For example, when the sensor is obstructed in some way, such as by the rest of the closure, the operator's arm, the operator's hand, or a tool carried by the operator, and the closure is actually in the open position, using a sensor (such as a proximity sensor or a light sensor) to determine whether the container's closure is in the open position and thus de-energize the circuit can easily generate a signal indicating that the closure is in the closed position.

[0043] Another possible failure mode associated with the previously conceived safety system is the failure of a single sensor. For example, a sensor used as part of the safety system may fail and / or may operate under conditions outside its rated operating conditions, such as operating in very warm or very cold weather. In another example, a single sensor may fail over time due to corrosion or wear.

[0044] Another possible failure mode related to the previously conceived safety system is a partial power supply failure. The active sensors used to determine whether the container's closure is in the closed position also require power. Therefore, a partial power supply failure to the active sensors can cause the safety system, including the active sensors, to malfunction.

[0045] Another possible failure mode associated with the previously conceived safety system is intermittent failure. Sensors used as part of the safety system may be intermittently triggered by vibration and / or shock loads applied during the transport of the electrical connection unit. This could cause any and all components powered by the circuitry contained within the electrical connection unit to shut down. Furthermore, this could lead to further technical problems. For example, if the electrical connection unit is formed as part of a transport refrigerated unit (TRU), the TRU may shut down under unsafe conditions. Additionally or alternatively, a series of intermittent shutdowns could lead to premature damage to the cargo carried by the TRU.

[0046] The electrical connection unit according to this disclosure can provide a relatively simple safety system that does not require a large number of components to function. This electrical connection unit also provides a safety system with a relatively simple manufacturing and assembly process. Furthermore, this electrical connection unit can provide a safety system with a more intuitive operator interface (requiring simple and intuitive connector disengagement for access to the internal components), which assures the operator that the circuitry contained within the electrical connection unit is de-energized.

[0047] exist Figure 1A , 1BIn the example shown in 1C, the closure 120 is shown connected to the container 110 via a hinge 130. The hinge 130 provides a connection between the container 110 and the closure 120, allowing the closure 120 to pivot relative to the container 110 between a closed position and multiple open positions. In this example, the closure extends from the hinge side (of the closure and the container) over the opening side of the container, wherein at the hinge side, the closure 120 is pivotally coupled to the lip side (of the closure and the container). In this particular example, the closure 120 is coupled to a hinged mount located at the midpoint along the hinge side of the closure 110, but in other examples, the hinged connection may be made elsewhere, for example, at the edge of the hinge side defining the opening side of the container. Although in this example the closure and the container are hinged, it should be understood that the closure 120 may be connected to the container 110 by various mechanisms, including a sliding connection. While perhaps impractical, a non-permanent connection can be made between the closure 120 and the container 110. For example, the closure 120 can be held on the container 110 by interlocking a connector with a locking element, and / or by a separate clamp or fastener that is removably applied to hold the closure 120 in a closed configuration.

[0048] exist Figure 1A , 1B In the example shown in 1C, the locking portion 122 is configured to overlap one side of the container 110 when in the closed position. The locking portion 122 hangs from the cap of the closure 120 in the form of a flange, which is generally parallel to the wall of the container 110 having the port 112 (“port wall”), and the locking portion 122 is laterally offset from the port wall such that it does not engage with the port 112 when the locking portion 122 moves relative to the container. The cap of the closure 120 is the portion of the closure that covers the opening of the container 110 when in the closed position. Therefore, there is a lateral gap between the port wall of the container and the locking portion, and the port 112 extends from the corresponding wall less than the separation gap. This allows the port 112 to protrude from the side of the container 110 (from the “port wall”) without impeding the movement of the closure 120 relative to the container 110 throughout its travel.

[0049] In other examples, the locking portion can be configured differently from the cover of the closure. As just one example, the port (i.e., the container has an opening and a panel forming one side of the container) can be provided on a panel adjacent to the opening of the container, and the locking portion can be substantially continuous with and adjacent to the cover of the closure.

[0050] Figure 2A side view of the electrical connection unit 100 in the closed position is shown, wherein the external connector 190 is coupled to the external port 112 via the connector opening 124 of the locking part 122. In this example, the connector opening 124 and the external connector 190 have corresponding cross-sectional profiles. When the external connector 190 is inserted through the connector opening 124 to engage with the external port 112 of the container 110, the corresponding cross-sectional profiles of the connector opening 124 and the external connector 190 define a clearance fit between them.

[0051] When the electrical connection unit 100 is in the closed configuration, the corresponding cross-sectional profiles of the connector opening 124 and the external connector 190, and optionally the limited gap between them, restrict the movement of the closure 120. This, in addition to preventing access to the interior of the container, also allows the closure to remain in the closed configuration to provide a seal between the closure 120 and the container 110, which protects the interior of the container from environmental conditions.

[0052] Interlocking can also occur when the cross-sectional profiles do not directly correspond. However, when the profiles of the connector and the connector opening correspond in at least a portion of their cross-sectional profiles, the locking portion can be configured to engage (i.e., abut) on the side of the connector opening in an interlocking manner over a larger area. This can reduce contact forces and wear on the connector and / or connector opening. Furthermore, corresponding cross-sectional profiles can facilitate proper alignment of the connector and port.

[0053] Figure 3 A side view of the electrical connection unit 100 in its extreme open position or maximum permissible open position is shown. The term "extreme" is used herein to mean that the corresponding open position is the limit position of the closure 120's travel relative to the container 110, or in other words, the boundary position of the closure 120's travel relative to the container 110. The extreme position can be defined by abutting a portion of the closure 120 against a portion of the container used to limit further travel. In this example, the closure 120 is provided with a closure stop 128, and the container 110 is provided with a container stop 118, the closure stop 128 and the container stop 118 engaging with each other through abutment contact, thereby preventing further movement of the closure from the closed position. Figure 3 In the example shown, the container stop 118 is the external port 112, but it should be understood that the container stop 118 may take an alternative form (e.g., the container stop may be provided by another part of the container or a part attached to the container).

[0054] In this example, the closure stop 128 is provided in the form of a shoulder that extends from the locking portion to at least partially span the separation gap between the port wall and the locking portion. Assuming a hinged connection between the closure and the container, the closure stop 128 is positioned relative to the locking portion such that when the closure 120 is in the closed configuration, the closure stop 128 is located at a small angle relative to the hinge along a rotational path from the closed position to the open position, wherein the closure stop 128 abuts the port 112 to define a limit open position. In this example, the closure stop 128 is located at the edge of the locking portion, the edge of which is aligned with the edge of the container between the port wall and the hinge side; however, it should be understood that other forms and positions are also possible.

[0055] The corresponding stop cooperates to limit the limited travel of the closure 120 relative to the container 110, which corresponds to the movement of the closure 120 relative to the container 110 between the closed position and the plurality of open positions passed through, as well as reaching the limit open position.

[0056] Figure 4 A side view of the electrical connection unit 100 in multiple open positions throughout the travel of the closure 120 relative to the container 110 is shown. In each open position, the locking part 122 at least partially covers the port 112, preventing the connector from passing through the connector opening 124 to engage with the port 112. To allow the connector to pass through the connector opening 124 to engage with the port 112, the closure 120 must be moved to a closed position. This prevents the connector from being engaged with the port 112 when the closure 120 is not in the closed position.

[0057] Therefore, when external connector 190 is connected to external port 112, access to the interior of the container is prevented because the container must be in the closed position for the connection to be established. (See below for reference.) Figure 6A -7 In more detail, access to the interior of container 110 is permitted only when the circuitry within container 110 is de-energized. Furthermore, when the closure 120 is open and an operator may be exposed to the circuitry, an attempt by the operator to connect connector 190 to port 112 is prohibited, as such an attempt would otherwise constitute a potential safety hazard to the electrical connection unit caused by the operator.

[0058] If the external connector 190 carries a hazardous voltage and its port is connected to a hazardous voltage circuit contained within the container 110, access to the interior of the container is permitted only when the hazardous voltage carried by the external connector 190 is completely removed from the electrical connection unit 100. Compared to previously conceived safety systems using lid sensors, this sensor can be used to de-energize the circuitry contained within the container 110 when the closure 120 is in the open position, but the hazardous voltage source may still physically exist within the container 110, even though the hazardous voltage source has been disconnected from the circuitry within the container 110. However, in such a system, the risk of an operator potentially coming into contact with the hazardous voltage source still exists. The electrical connection unit according to this disclosure can be used to ensure that the hazardous voltage source is not physically present within the container 110 when the closure 120 is in the open position. Therefore, the risk of an operator coming into contact with the hazardous voltage source is eliminated.

[0059] Port 112 may be provided with a housing 114, which is configured to prevent the electrical contacts in port 112 from being exposed. Port 112 and housing 114 may be configured to provide a level of protection against the intrusion of foreign objects and / or water. Port 112 and housing 114 may be configured to provide at least IP11B protection according to IEC standard 60529 (EN 60529), but preferably, IP22B protection, and particularly IP43B protection.

[0060] Similarly, the external connector 190 can be configured (e.g., it can be constructed or shaped to) prevent the electrical contacts in the external connector 190 from being exposed. The external connector 190 can provide a level of protection against the intrusion of foreign matter and / or water. The external connector 190 can provide at least an IP11B protection rating according to IEC standard 60529 (EN 60529), but preferably, an IP22B protection rating, and particularly an IP43B protection rating. Additionally, the external connector 190 can be configured (e.g., constructed or shaped to) suppress arc flashes and / or arc impacts originating from the electrical contacts in the external connector 190.

[0061] Figure 5A , 5B Figures 5C and 5C respectively illustrate a second exemplary electrical connection unit 100', a first external connector 190, and a second external connector 191, wherein the electrical connection unit 100 includes a container 110 and a closure 120. The container 110 is provided with a first external port 112 configured to connect to the first external connector 190, and a second external port 113 configured to connect to the second external connector 191.

[0062] The container 110, the closure 120, each port, and each associated locking part may have any of the features described above with respect to the first exemplary electrical connection unit 100. The closure 120 of the electrical connection unit 100 can only be moved from the closed position to the open position when neither of the two external connectors is connected to the corresponding external port.

[0063] like Figure 5A , 5B As shown in example 5C, the first locking part 122 and the second locking part 123 can be provided on opposite sides of the container 110. This makes the electrical connection unit 100 more resistant to prying actions applied to the closure 120 by an operator when the electrical unit 100 is in the closed position.

[0064] Figure 6A An exemplary hazardous voltage circuit 600 in a powered state is shown. Figure 6B The same exemplary hazardous voltage circuit 600 in a de-energized state is shown. Hazardous voltage circuit 600 may form at least a portion of the circuit disposed within the container 110 of the electrical connection units 100, 100' as described above with respect to Figures 1-5; however, those skilled in the art will understand that the circuit disposed within the container 110 may include many different components or elements. Therefore, it should be understood that the circuit shown and described herein... Figure 6A and 6B The exemplary dangerous voltage circuit 600 is for the purpose of explaining the safety features of the electrical connection unit 100.

[0065] In the following disclosure, the hazardous voltage circuit 600 will be described with reference to the first exemplary electrical connection unit 100 of Figures 1-5.

[0066] Figure 6A and 6B The hazardous voltage circuit 600 shown includes a hazardous voltage source 602 and an electrical load 604, wherein the hazardous voltage source 602 may be, for example, a source of shore power (such as a mains electrical outlet), and the electrical load 604 may be, for example, one or more components of a transport refrigeration unit (e.g., a compressor, pump, etc.). Therefore, the hazardous voltage source 602 supplies power to the load 604.

[0067] A hazardous voltage is a voltage that poses a significant risk to human health if a human operator approaches or comes into contact with a circuit that conducts a hazardous voltage. The significant health risks posed by hazardous voltages may stem from the risk of electric shock or electrocution, and / or from the risk of arc flashes and / or arc impacts. Hazardous voltage can be defined as a direct current (DC) voltage equal to or greater than 60 V, and / or an alternating current (AC) voltage equal to or greater than 30 V RMS. Hazardous voltage can also be defined as a voltage classified as Class B or higher according to ISO 6469-3.

[0068] The hazardous voltage circuit 600 in the illustrated example also includes a fuse 606 and / or a residual current device 608 (also commonly referred to as a ground fault circuit interrupter, equipment leakage current interrupter, or leakage current detection interrupter). The fuse 606 is configured to trip when the current flowing through the fuse 606 exceeds a threshold current, thereby disconnecting or interrupting the current path between the source 602 and the load 604, thus de-energizing the hazardous voltage circuit 600. The residual current device 608 is configured to trip or interrupt the current path between the source 602 and the load 604 when a leakage current exceeding a leakage current threshold is detected, thereby de-energizing the hazardous voltage circuit 600. The hazardous voltage circuit 600 may include multiple fuses, residual current devices, and / or routing devices to control the delivery of power to one or more electrical loads.

[0069] The hazardous voltage circuit 600 can be enabled by connecting the external connector 190 to the external port 112 of the electrical connection unit 100, and disabled by disconnecting the external connector 190 from the external port 112. The external port may be provided with a sensing device configured to energize the hazardous voltage circuit when the external connector is connected to the external port. In one example, when the external connector 190 is connected to the external port 112 to close a mechanical switch (e.g., a push-to-close switch), a physical feature of the external connector 190 (e.g., a protrusion) engages with a complementary physical feature of the external port 112 (e.g., a lever or other mechanical engagement structure) to allow current to flow in the hazardous voltage circuit 600, thereby energizing the hazardous voltage circuit 600. In another example, external port 112 is provided with a proximity sensor and / or a contact sensor, which are configured to turn off the switch (e.g., an electrical switch, electronic switch, or mechanical switch) of the hazardous voltage circuit 600 when external connector 190 is connected to external port 112, so that current can flow in the hazardous voltage circuit 600, thereby energizing the hazardous voltage circuit 600.

[0070] Optionally, the external connector 190 may carry an electrical control signal provided to the hazardous voltage interlock circuit. The electrical control signal may be a non-hazardous voltage. The external connector 190 may also carry a non-hazardous voltage provided to a non-hazardous voltage circuit. The hazardous voltage interlock circuit is configured to allow current to flow in the hazardous voltage circuit 600 when the electrical control signal is provided to it, for example, by activating an electrical or electronic switch (such as a transistor, relay, thyristor, etc.) of the hazardous voltage circuit 600. Therefore, when the external connector 190 is connected to the external port 112, the hazardous voltage circuit 600 is energized, allowing current to flow in the hazardous voltage circuit 600, and when the external connector is disconnected from the external port, the hazardous voltage circuit is de-energized, preventing current from flowing in the hazardous voltage circuit 600.

[0071] The hazardous voltage interlock circuit may also be equipped with a hazardous voltage interlock circuit monitor. This monitor can be configured to compare the current supplied to the hazardous voltage interlock circuit with the current received from the hazardous voltage interlock circuit via external connector 190. The monitor is configured to de-energize the hazardous voltage circuit 600 in response to the difference between the individual currents exceeding a threshold.

[0072] After preventing current from flowing into the hazardous voltage circuit during a power outage, the stored charge can remain in any capacitive element within the hazardous voltage circuit. The hazardous voltage interlock circuit may also include a discharge circuit configured to completely discharge any remaining stored charge in the hazardous voltage circuit when the circuit is de-energized. The discharge circuit can be an active or passive discharge circuit.

[0073] External connectors can be hazardous voltage connectors carrying hazardous voltage power, or they can be non-hazardous voltage connectors carrying non-hazardous voltage control signals and / or non-hazardous voltage power. Hazardous voltage interlock circuits can form part of a non-hazardous voltage circuit that supplies non-hazardous voltage from a non-hazardous voltage source to a non-hazardous voltage load.

[0074] If the external connector carries a hazardous voltage, the external connector 190 and external port 112 can be configured to ensure that, during the disconnection of the connector from the port, the hazardous voltage interlock circuit removes the electrical control signal by physically disconnecting the electrical contacts before the hazardous voltage circuit 600 removes the hazardous voltage by physically disconnecting the electrical contacts. Therefore, the hazardous voltage interlock circuit ensures that the hazardous voltage circuit 600 is de-energized before removing the hazardous voltage by physically disconnecting the electrical contacts. This reduces the risk of arcing and / or arcing between the electrical contacts during the disconnection of the connector from the port.

[0075] Mechanical or electrical / electronic switches that are actuated or controlled based on the connection status between the external connector and the external port. Figure 6A This is represented by switch 690. When an external connector is connected to an external port, switch 690 is in the closed state (e.g., ...). Figure 6A As shown), and because there is a current path from source 602 to load 604 through closed switch 690, dangerous voltage circuit 600 is energized.

[0076] Additionally or optionally, the hazardous voltage interlock circuit can be configured to energize or de-energize the hazardous voltage circuit 600 by sending a signal to the hazardous voltage source 602 to connect it to or isolate it from the electrical connection unit 100' based on the connection status of the external connector. In this case, the connection status of the hazardous voltage source 602 is indicated by the switch 690. As described above, when the external connector is connected to the external port, the connection switch 690 is in the closed state (e.g., when the external connector is connected to the external port). Figure 6A As shown), and because there is a current path from source 602 to load 604 through closed switch 690, dangerous voltage circuit 600 is energized.

[0077] When the external connector is not connected to the external port, the connection switch 690 is in the open state (e.g., Figure 6B As shown, since there is no current path from source 602 to load 604, the dangerous voltage circuit 600 is de-energized.

[0078] Figure 7A A method for coupling a connector to a port of an electrical connection unit 100 according to any of the foregoing examples is illustrated. The method includes, at 701, optionally moving the closure 120 of the container 110 to a closed position if the closure 120 is not already in the closed position. Then, with the closure 120 in the closed position, at 702, coupling an external connector 190 to an external port 112 of the container 110 through a connector opening 124 of a locking portion 122 of the closure 120.

[0079] Figure 7B A method for disconnecting a connector from the port of an electrical connection unit is illustrated. The method includes, at 703, disconnecting the external connector 190 from the external port 112 of the container 110 through the connector opening 124 of the locking portion 122 of the closure 120. Optionally, then at 704, the closure 120 can be moved from a closed position to an open position.

Claims

1. An electrical connection unit for a refrigeration system, the electrical connection unit comprising: A container, the container defining an interior for housing circuitry, the container having an external port configured to connect to an external connector; A closure member, the closure member being movable relative to the container between a closed configuration preventing access to the interior and an open configuration allowing access to the interior. The closure has a locking portion that defines a connector opening for receiving the external connector. The container and the closure are configured such that, when the closure is in the closed configuration, the connector opening is aligned with the external port to allow the external connector to engage with the external port through the connector opening for interlocking with the closure. Thus, the interlocking engagement between the external connector and the closure prevents the closure from moving into the open configuration. The container and the closure cooperate to limit a limited travel distance of the closure relative to the container between the closed configuration and the open configuration of the closure; The closure and the container are configured such that, throughout the entire travel except in the closed configuration, the locking portion of the closure at least partially covers the external port to prevent the external connector from engaging with the external port when the closure is in the open configuration.

2. The electrical connection unit according to claim 1, wherein, The closure is connected to the container via a hinge.

3. The electrical connection unit according to claim 1, wherein, The locking portion is configured to overlap one side of the container when in a closed configuration; and / or wherein the locking portion hangs from the lid of the closure in the form of a flange.

4. The electrical connection unit according to any one of claims 1 to 3, wherein, The external port is provided with a housing configured to prevent the electrical contacts in the external port from being exposed.

5. The electrical connection unit according to any one of claims 1 to 3, wherein, The container includes a hazardous voltage interlock circuit that is electrically connected to the external port and configured to selectively energize or de-energize the hazardous voltage circuit.

6. The electrical connection unit according to claim 5, wherein, The dangerous voltage interlock circuit forms part of the non-dangerous voltage circuit.

7. The electrical connection unit according to any one of claims 1 to 3, wherein, The external port is equipped with a sensing device configured to de-energize the dangerous voltage circuit when the external connector is not connected to the external port.

8. The electrical connection unit according to any one of claims 1 to 3, wherein the electrical connection unit includes two external ports, each external port being configured to connect to an external connector, wherein, For each external port: The closure has a corresponding locking part that defines a connector opening for receiving a corresponding external connector; The container and the closure are configured such that when the closure is in the closed configuration, the corresponding external connector opening is aligned with the external port to allow the corresponding external connector to be connected to the external port through the connector opening for interlocking with the closure. Thus, the interlocking engagement between the external connector and the closure prevents the closure from moving into the open configuration.

9. The electrical connection unit according to claim 8, wherein, The locking part is located on the opposite side of the container.

10. A component comprising an electrical connection unit according to any one of claims 1 to 9 and a connector configured to be coupled to the external port or to at least one of the external ports.

11. The component of claim 10, wherein, The connector and the corresponding connector opening have corresponding cross-sectional profiles.

12. A refrigeration system comprising an electrical connection unit according to any one of claims 1-9 or a component according to any one of claims 10-11.

13. A method, the method comprising: The connector is connected or disconnected from an external port in the electrical connection unit according to any one of claims 1 to 7 or an external port in the electrical connection unit according to claim 8 or 9 when the enclosure is in the closed configuration.

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