Controlling and measuring the power consumption of a heating element with a pilot wire using a multicore cable

Abstract

The invention relates to a heating system (1) comprising: - an installation comprising a heating element (3), a power source (5) and a pilot wire terminal (FP) designed to control the heating element (3) by pilot wire, and - an intermediate device (9) connected to the installation by a multicore cable (15) with a view to controlling and / or measuring a power consumption of the heating element (3). The multicore cable (15) comprises an input pilot wire conductor (FPI), an output pilot wire conductor (FPO), an input phase conductor (LI) and an output phase conductor (LO) for electrically inserting the intermediate device (9) within the installation. The multicore cable (15) comprises a single neutral conductor (N9) for connecting the intermediate device (9) to the power source (5). The heating element (3) is connected directly to the power source (5) by a neutral conductor (N3).

Description

Control and measurement of the electrical consumption of a heating element with a pilot wire via a multi-conductor cable

[0001] This application incorporates by reference the content of French patent application FR 2 411 196 filed on October 16, 2024.

[0002] The field of the invention relates to the control and measurement of the electrical consumption of a heating element, for example an electric radiator, with pilot wire function.

[0003] The operation of an electric radiator is based on the principle of converting, by an electrical resistance, the electrical energy supplied by a power source into thermal energy.

[0004] To adapt to a user's needs, an electric radiator is equipped with an interface allowing the selection of an operating mode and a set temperature. An electric radiator generally has at least four operating modes, named "comfort", "eco", "frost protection" and "off".

[0005] In "comfort" mode, the electric radiator operates at the set temperature. In "eco" mode, the electric radiator lowers the set temperature, generally by 3 to 4°C, compared to "comfort" mode. In case of prolonged absence, the user can activate "frost protection" mode to maintain a minimum temperature to prevent any risk of freezing, particularly in the pipes. Finally, "off" mode prevents the electric radiator from emitting heat. An electric radiator may have two additional modes, called "comfort -1°C" and "comfort -2°C," in which the set temperature is lowered by 1 and 2°C respectively compared to "comfort" mode.

[0006] To avoid repeated interventions on the interface, or when the user has several electric radiators, it is advantageous to use a programmer installed at home and connected to each electric radiator by a pilot wire. The programmer allows you to program in advance the desired operating mode for each time period or for a prolonged absence. The interface of an electric radiator with a pilot wire function includes, for example, an "automatic" mode in which the electric radiator follows the signal transmitted by the programmer via the pilot wire.

[0007] In addition to the programmer, the user can install a control and / or measurement device for the electrical consumption of the electric radiator with pilot wire function.

[0008] This illustrates a typical wiring diagram for such a device. The figure shows an electric heater 3, a power supply 5, a timer 7, and a device 9 for controlling and / or measuring the power consumption of the electric heater 3. The electric heater 3 is supplied with electrical energy by the power supply 5 via a phase conductor (terminal "L"), while a neutral conductor (terminal "N") allows the return of electrical current to the power supply 5. The timer 7 is configured to control the electric heater 3 via a pilot wire (terminal "FP").

[0009] Device 9 is electrically interposed between the electric radiator 3 and the programmer 7, and therefore has a pilot wire input terminal FP1 and an output terminal FP2. Device 9 is also electrically interposed between the electric radiator 3 and the power supply 5. To achieve this, device 9 has not only an input phase terminal L1 and an output phase terminal L2, but also an input neutral terminal N1 and an output neutral terminal N2. The input terminal L1 and the output terminal L2 are generally connected to each other via a shunt, which allows the electrical consumption of the electric radiator 3 to be measured.

[0010] The neutral input terminal N1 and the neutral output terminal N2 of device 9 are intended to isolate the electric radiator 3 from the rest of the user's home electrical system. However, the electric radiator 3 is purely resistive, so it does not generate any noise that could disrupt the rest of the electrical system and is not sensitive to electromagnetic noise. Therefore, such isolation is unnecessary, and current wiring does not take these characteristics of the electric radiator into account.

[0011] Furthermore, in the example shown, several single-conductor electrical cables, six in total, are used to connect device 9 to the electric heater 3, the power supply 5, and the timer 7, resulting in a complex and bulky wiring system. These single-conductor electrical cables could be replaced by a multi-conductor electrical cable, but in such a cable, all the conductors have the same diameter, and these dimensions do not account for the difference in electrical current between conductors. Oversizing represents a waste of material, particularly copper, in the manufacture of such a multi-conductor electrical cable.

[0012] The present invention improves the situation.

[0013] In this respect, the present invention relates to a heating system, comprising: a heating installation including a heating element arranged to emit heat, an electrical power supply arranged to supply the heating element with electrical energy by phase conductor, and a pilot wire terminal arranged to control the heating element by pilot wire, and an intermediate device arranged to control and / or measure the electrical consumption of the heating element and connected to the installation by a multi-conductor cable.

[0014] The multi-conductor cable includes, on the one hand, an input pilot wire conductor and an output pilot wire conductor, and, on the other hand, an input phase conductor and an output phase conductor to electrically interpose the intermediate device between the heating element and, respectively, the pilot wire terminal and the power supply source.

[0015] The multi-conductor cable further includes a single neutral conductor to connect the intermediate device to the power supply; the multi-conductor cable includes at most five conductors, and the heating element is connected by a neutral conductor directly to the power supply.

[0016] In one or more embodiments, the single neutral conductor of the multi-conductor cable has a cross-section strictly smaller than that of the neutral conductor at the output of the heating element.

[0017] Advantageously, the single neutral conductor of the multi-conductor cable has a cross-section strictly less than 1.5 mm² 2 .

[0018] Preferably, the single neutral conductor of the multi-conductor cable has a cross-section strictly less than 0.75 mm² 2 .

[0019] In one or more embodiments, the input pilot wire conductor and the output pilot wire conductor each have a cross-section strictly less than 1.5 mm² 2 and the input phase conductor and the output phase conductor each have a cross-section greater than or equal to 1.5 mm 2 .

[0020] In one or more embodiments, each conductor of the multi-conductor cable comprises copper.

[0021] In one or more embodiments, the multi-conductor cable includes a thermoplastic insulation sheath.

[0022] In one or more embodiments, the single neutral conductor of the multi-conductor cable and the neutral conductor at the output of the heating element are connected to the power supply via a common neutral conductor. The neutral conductors may be connected together using a wire clamp.

[0023] In one or more embodiments, the intermediate device includes a shunt arranged to measure an electric current flowing between the input phase conductor and the output phase conductor supplying the heating element with electrical energy.

[0024] In one or more embodiments, the intermediate device includes a relay arranged to selectively control the supply of electrical energy to the heating element by opening and closing a switch between the input phase conductor and the output phase conductor.

[0025] Other features, details, and advantages will become apparent upon reading the detailed description below and analyzing the attached drawings, which illustrate this.

[0026] illustrates a wiring diagram, according to the prior art, of a device for controlling and / or measuring the electrical consumption of a heating element with several single-conductor electrical cables;

[0027] illustrates a wiring diagram, according to the invention, of a device for controlling and / or measuring the electrical consumption of a heating element with a multi-conductor electrical cable; and

[0028] illustrates a cross-sectional view of the multi-conductor electrical cable.

[0029] Laillustre un diagram de wiring du system de chauffage 1.

[0030] Heating system 1 can be installed in any type of dwelling to improve domestic thermal comfort. Heating system 1 is designed to transfer thermal energy to the dwelling according to a centralized program.

[0031] The heating system 1 includes a heating element 3, an electrical power supply 5 and a programmer 7. The heating system 1 also includes a device 9 for controlling and / or measuring the electrical consumption of the heating element 3.

[0032] The heating element 3 is arranged to emit heat. The heating element 3 is, for example, an electric radiator comprising an electrical resistance arranged to convert electrical energy into thermal energy by the Joule effect.

[0033] It is common knowledge among those skilled in the art that there are different types of electric radiators. Among the existing electric radiators, the most common is the electric convector. An electric convector takes the form of a metal box with an opening at the bottom and another at the top. Cold air enters the lower section and is heated by contact with the electric heating element. The warm air, being less dense than the cold air, rises in the upper section and exits the metal box, while the cold air is replenished in the lower section.

[0034] An electric radiator can also be a radiant heater, also called a radiant panel heater, in which an electrical resistance heats a plate or panel. The plate or panel emits thermal radiation, primarily in the infrared range, to transfer heat directly to the walls of a room or to the people inside.

[0035] As another example, an electric radiator can also be a storage heater containing a refractory material that stores the heat generated by the electrical resistance. Typically, the electric radiator stores heat during off-peak hours and then releases the accumulated heat during peak hours.

[0036] Furthermore, the heating element 3 is designed to adapt to a user's needs. For example, the heating element 3 includes an interface for selecting an operating mode and a setpoint temperature. This interface acts as a thermostat. The heating element 3 generally has at least four operating modes, named "comfort," "eco," "frost protection," and "off."

[0037] In "comfort" mode, heating element 3 attempts to raise the room temperature to the setpoint. In "eco" mode, heating element 3 lowers the setpoint temperature, generally by 3 to 4°C, compared to "comfort" mode. The "frost protection" mode, in case of prolonged absence, prevents the room temperature from falling below a minimum temperature – usually around 7°C – to avoid any risk of freezing, particularly in the pipes. Finally, the "off" mode turns off heating element 3, thus stopping any attempt to adjust the room temperature.

[0038] Furthermore, heating element 3 can have two additional modes, named "comfort -1°C" and "comfort -2°C", in which the setpoint temperature is lowered by 1 and 2°C respectively compared to the "comfort" mode.

[0039] The power supply 5 is arranged to supply the heating element 3 with electrical energy via phase conductor.

[0040] The heating element 3 and the power supply 5 each have a phase terminal L and a neutral terminal N. The respective phase terminals L allow the power supply 5 and the heating element 3 to be connected via a phase conductor to supply the heating element 3 with an electric current. Since there is only one phase conductor, this is a single-phase current. The respective neutral terminals N allow a neutral conductor to be connected between the power supply 5 and the heating element 3 to ensure the return of the electric current to the power supply 5.

[0041] The live conductor and the neutral conductor can be distinguished by their color. For example, according to the international standard IEC 60445:2021, the live conductor is brown, black or gray while the neutral conductor is blue.

[0042] The power supply 5 is typically an alternating current source. The voltage of the electric current supplied by the power supply 5 varies periodically between a positive value and a negative value.

[0043] In Europe, in a low-voltage distribution network, the voltage oscillates at a frequency of 50 hertz (Hz) between a maximum peak voltage of 320 volts (V) and a minimum peak voltage of -320 volts (V), resulting in a peak-to-peak voltage of 640 volts (V). This oscillation produces an effective voltage (RMS) of 230 volts (V). The RMS value of an alternating voltage corresponds to the value of a direct current (DC) voltage that produces the same heat output in an identical electrical resistance. Traditionally, multimeters and power network monitoring devices display the RMS voltage. The peak voltage is rarely measured.

[0044] Programmer 7 is arranged to control heating element 3 via pilot wire.

[0045] Pilot wire technology allows for centralized, time-based management of multiple heating elements to save energy or specifically target off-peak hours to reduce costs. In the example shown, only one heating element 3 is represented. However, the heating system 1 can include several heating elements, all controlled by the same programmer 7.

[0046] The heating element 3 and the controller 7 each have a pilot wire terminal FP, allowing the controller 7 and the heating element 3 to be connected via a pilot wire. The controller 7 can send a control signal to the heating element 3 in the form of a low-current electrical signal flowing through the pilot wire. The current in the pilot wire is typically less than 0.1 ampere (A).

[0047] In the example described here, the programmer 7 is a wall-mounted unit comprising a user interface 11 and a screen 13. The programmer 7 can be supplied with electrical power from the electrical distribution panel of the user's dwelling and be protected by a 2 amp (A) circuit breaker.

[0048] User interface 11 is designed to allow the user to configure programmer 7. The user can use user interface 11 to program the operation of heating element 3 in advance for each time slot. Daily programming consists of selecting the appropriate operating mode for heating element 3 for each time slot of the day.

[0049] For example, it is common for a user to select "comfort" mode for the times they are present and "eco" mode for the times they are absent. In case of a prolonged absence, the user can program "frost protection" mode for the corresponding period.

[0050] Typically, programmer 7 sends: an alternating electrical signal for "eco" mode, for example, a signal whose voltage varies periodically between 320 volts (V) and -320 volts (V); a positive alternating electrical signal for "off" mode, for example, a signal whose voltage varies periodically between 320 volts (V) and 0 volts (V); and a negative alternating electrical signal for "frost protection" mode, for example, a signal whose voltage varies periodically between -320 volts (V) and 0 volts (V). Finally, the absence of an electrical signal corresponds to "comfort" mode.

[0051] Screen 13 is designed to display information relating to heating element 3 and the selected programming. For example, screen 13 displays the current operating mode of heating element 3, the setpoint temperature corresponding to the "comfort" mode, or the programming for upcoming time periods, whether for daily use or for an extended absence.

[0052] The heating element 3, the power supply 5 and the programmer 7 form a heating installation of heating system 1.

[0053] Device 9 is arranged to control and / or measure the electrical consumption of the heating element 3. To do this, device 9 is connected to the heating installation by a multi-conductor cable 15. More specifically, device 9 is electrically interposed between the heating element 3 and the electrical supply source 5.

[0054] In order to measure the electrical consumption of the heating element 3, the device 9 includes for example a shunt 17. The shunt 17 is a resistor arranged to measure the electric current flowing in the phase conductor supplying the heating element 3 with electrical energy.

[0055] Generally, a voltmeter is connected in parallel to measure the voltage across the shunt 17 and deduce the current intensity by applying Ohm's law.

[0056] Solutions other than the use of a shunt are known for measuring the electrical consumption of a heating element.

[0057] In order to control the electrical consumption of the heating element 3, the device 9 includes, for example, a relay 19. The relay 19 is arranged to selectively control the supply of electrical energy to the heating element 3 by opening and closing a switch on the phase conductor supplying electrical energy to the heating element 3.

[0058] Relay 19, for example, is an electromechanical relay comprising an electromagnet whose electrical supply results in the mechanical opening or closing of the switch via a paddle.

[0059] Solutions other than using a relay are known for controlling the electrical consumption of a heating element. For example, a pilot wire device can transmit a command via the pilot wire to the heating element 3 independently of the command transmitted by the programmer 7 to control the electrical load.

[0060] In the example shown, device 9 is configured both to measure and control the electrical consumption of heating element 3. However, device 9 may be configured only to measure or control the electrical consumption of heating element 3.

[0061] Contrary to the prior art wiring diagram shown on the, device 9 is connected to the heating installation by the multi-conductor cable 15 and not by several single-conductor cables.

[0062] The 15 multi-conductor cable comprises five conductors, namely an input phase conductor LI, an output phase conductor LO, an input pilot wire conductor FPI, an output pilot wire conductor FPO and a single neutral conductor N9.

[0063] Typically, each conductor in a 15-core multi-conductor cable contains copper. Furthermore, the 15-core multi-conductor cable may be protected by a thermoplastic insulation sheath. Such an insulation sheath is typically made from thermoplastic materials, such as polyvinyl chloride (better known by its English acronym "PVC") or polyethylene.

[0064] Advantageously, the 15 multi-conductor cable includes only the five conductors mentioned above and therefore does not include any additional conductors.

[0065] The input phase conductor LI and the output phase conductor LO allow the device 9 to be electrically interposed between the power supply 5 and the heating element 3. The input phase conductor LI is connected to the phase terminal of the power supply 5, while the output phase conductor LO is connected to the phase terminal of the heating element 3. The junction between the input phase conductor LI and the output phase conductor LO is made at the device 9. In the example shown, the input phase conductor LI and the output phase conductor LO are connected via the relay switch 19. However, the input phase conductor LI and the output phase conductor LO can also be connected via the shunt 17, each then being connected to one of its terminals.

[0066] Furthermore, the input phase conductor LI allows the power supply source 5 to supply the device 9 with electrical energy.

[0067] The FPI input pilot wire conductor and the FPO output pilot wire conductor allow the device 9 to be electrically interposed between the programmer 7 and the heating element 3. The FPI input pilot wire conductor is connected to the pilot wire terminal of the programmer 7, while the FPO output pilot wire conductor is connected to the pilot wire terminal of the heating element 3. Again, the connection between the FPI input pilot wire conductor and the FPO output pilot wire conductor is made at the device 9.

[0068] It should be noted that the input pilot wire FPI and the output pilot wire FPO are generally independent of each other. In other words, the setpoint received by device 9 on the input pilot wire FPI is not necessarily replicated on the output pilot wire FPO. Device 9 can therefore impose a different setpoint on the output pilot wire FPO to the heating element 3 without taking into account the one received from the programmer 7. Of course, device 9 can also apply the same setpoint.

[0069] Therefore, device 9 is an intermediate device within the heating installation in that it is electrically interposed between the heating element 3 and, on the one hand, the power supply 5, and, on the other hand, the programmer 7.

[0070] The neutral conductor N9 allows the device 9 to be connected to the power supply source 5. As explained previously, the device 9 is supplied with electrical energy by phase conductor, in this case the input phase conductor LI, so the neutral conductor N9 allows the return of the electrical current to the power supply source 5.

[0071] Whereas two neutral conductors are connected to device 9 in the prior art wiring diagram shown on the, only one neutral conductor, here referenced N9, is connected to device 9 in the wiring diagram shown on the.

[0072] Unlike the prior art wiring diagram, the heating element 3 is connected via a neutral conductor N3 directly to the power supply 5. "Directly connected" here means that the neutral conductor N3 exiting the heating element 3, which allows the return current to the power supply 5, is not connected to, nor does it pass through, the device 9. The device 9 is therefore an intermediate device between the heating element 3 and the power supply 5, but only for the phase conductor and not for the neutral conductor.

[0073] As explained previously, a multi-conductor cable can be used in the prior art to connect device 9 to the heating system. Such a multi-conductor cable then comprises six conductors. In the wiring diagram proposed here, the multi-conductor cable 15 comprises only five conductors, thus simplifying the wiring and saving copper.

[0074] Furthermore, the neutral conductor N9 of the multi-conductor cable 15 and the neutral conductor N3 at the output of the heating element 3 can be connected to the power supply 5 via a common neutral conductor N5. The neutral conductors N9 and N3 are then connected together, for example, by a terminal block 21. The terminal block 21, also known as a connector, further simplifies the wiring. Indeed, only one neutral terminal is then required on the power supply 5.

[0075] Laillustre a cross-sectional view of the multi-conductor cable 15.

[0076] More specifically, lamontre a cross section 23 of the multiconductor cable 15 corresponding to its intersection with a plane orthogonal to the local direction of the multiconductor cable 15.

[0077] Lamet highlights the fact that, in addition to saving a conductor, the wiring scheme allows for resizing of conductors to achieve additional copper savings.

[0078] This resizing takes into account the intensity of the electric current flowing in each conductor of the multi-conductor cable 15. In the following description, a "high intensity" corresponds to a current of more than 16 amperes (A) while a "low intensity" corresponds to a current of less than 3 amperes (A).

[0079] The main difference concerns the single neutral conductor N9 at the output of device 9. In the prior art wiring diagram, the electric current flowing in the neutral conductor between device 9 and the power supply 5 is high. This high current corresponds to the sum of the low current required for the operation of device 9 and the high current required for the operation of the heating element 3. However, in the proposed wiring diagram, the neutral conductor N3 at the output of the heating element 3 is not connected to device 9. Consequently, the electric current flowing in the neutral conductor N9 between device 9 and the power supply 5 is low, as it corresponds to the power consumption of device 9 alone.

[0080] The wiring diagram allows the neutral conductor N9 to have a cross-section strictly smaller than that of the neutral conductor N3 at the output of the heating element 3.

[0081] The neutral conductor N9 advantageously has a cross-section strictly less than 1.5 mm² 2 Preferably, the neutral conductor N9 has a cross-section strictly less than 0.75 mm² 2 The cross-section of the neutral conductor N9 can even be reduced to 0.5 mm². 2 .

[0082] The input phase conductor LI and the output phase conductor LO carry a high-intensity electric current. This is because the input phase conductor LI supplies electrical power to device 9 and heating element 3, while the output phase conductor LO supplies electrical power to heating element 3. Typically, both the input phase conductor LI and the output phase conductor LO have a cross-sectional area greater than or equal to 1.5 mm². 2 .

[0083] As explained previously, the control signal transmitted by the programmer 7 to the heating element 3 is a low-intensity electrical signal traveling in the pilot wire. Typically, the input pilot wire conductor FPI and the output pilot wire conductor FPO each have a cross-section strictly less than 1.5 mm². 2Advantageously, the FPI input pilot wire conductor and the FPO output pilot wire conductor can each have a cross-section strictly less than 0.75 mm². 2 , and even at 0.5 mm 2 .

[0084] The 15 multi-conductor cable therefore includes conductors with a dimension adapted to the intensity of the electric current, which allows for savings in material, particularly copper, unlike a standard multi-conductor cable which includes conductors of the same dimension.

Claims

Heating system (1), comprising: a heating installation including a heating element (3) arranged to emit heat, an electrical power supply (5) arranged to supply said heating element (3) with electrical energy via a phase conductor, and a pilot wire terminal (FP) arranged to control said heating element (3) via a pilot wire, and an intermediate device (9) arranged to control and / or measure the electrical consumption of said heating element (3) and connected to said installation by a multi-conductor cable (15), said multi-conductor cable (15) comprising, on the one hand, an input pilot wire conductor (FPI) and an output pilot wire conductor (FPO), and, on the other hand, an input phase conductor (LI) and an output phase conductor (LO) for electrically interposing said intermediate device (9) between the heating element (3) and, respectively,the pilot wire terminal (FP) and the power supply (5), said heating system (1) being characterized in that the multi-conductor cable (15) further comprises a single neutral conductor (N9) for connecting said intermediate device (9) to the power supply (5), the multi-conductor cable (15) comprises at most five conductors, and said heating element (3) is connected by a neutral conductor (N3) directly to said power supply (5). Heating system (1) according to claim 1, characterized in that the single neutral conductor (N9) of the multi-conductor cable (15) has a cross-section strictly smaller than that of the neutral conductor (N3) at the output of the heating element (3). Heating system (1) according to claim 1 or 2, characterized in that the single neutral conductor (N9) of the multi-conductor cable (15) has a cross-section strictly less than 1.5 mm² 2 . Heating system (1) according to claim 3, characterized in that the single neutral conductor (N9) of the multi-conductor cable (15) has a cross-section strictly less than 0.75 mm² 2 . Heating system (1) according to any one of the preceding claims, characterized in that the inlet pilot wire conductor (IPC) and the outlet pilot wire conductor (OPC) each have a cross-section strictly less than 1.5 mm² 2 and the input phase conductor (LI) and the output phase conductor (LO) each have a cross-section greater than or equal to 1.5 mm 2 . Heating system (1) according to any one of the preceding claims, characterized in that each conductor of the multiconductor cable (15) comprises copper. Heating system (1) according to any one of the preceding claims, characterized in that the multi-conductor cable (15) comprises a thermoplastic insulation sheath. Heating system (1) according to any one of the preceding claims, characterized in that the single neutral conductor (N9) of the multiconductor cable (15) and the neutral conductor (N3) at the output of the heating element (3) are connected to the power supply (5) via a common neutral conductor (N5). Heating system (1) according to any one of the preceding claims, characterized in that the intermediate device (9) comprises a shunt (17) arranged to measure an electric current flowing between the input phase conductor (LI) and the output phase conductor (LO) supplying the heating element (3) with electrical energy. Heating system (1) according to any one of the preceding claims, characterized in that the intermediate device (9) comprises a relay (19) arranged to selectively control the supply of electrical energy to the heating element (3) by opening and closing a switch between the input phase conductor (LI) and the output phase conductor (LO).

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