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

Abstract

The invention relates to a heating system (1), comprising: an installation including a heating element (3), a power supply (5), and a pilot wire terminal (FP) arranged to control the heating element (3) by pilot wire, and an intermediate device (9) connected to the installation by a multi-conductor cable (15) for controlling and / or measuring the power consumption of the heating element (3). The multi-conductor cable (15) includes 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 interposing the intermediate device (9) within the installation. The multi-conductor cable (15) includes a single neutral conductor (N9) for connecting the intermediate device (9) to the power supply (5). The heating element (3) is connected by a neutral conductor (N3) directly to the power supply (5).[Fig. 2].

Description

Title of the invention: Control and measurement of the electrical consumption of a heating element with a pilot wire using a multi-conductor cable

[0001] 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.

[0002] 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.

[0003] To adapt to a user's needs, an electric radiator is equipped with an interface allowing the selection of an operating mode and a setpoint temperature. An electric radiator generally has at least four operating modes, named "comfort", "eco", "frost protection" and "off".

[0004] 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.

[0005] 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 the desired operating mode to be programmed in advance 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.

[0006] 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.

[0007] [Fig. 1] illustrates a typical wiring diagram of such a device. This figure shows an electric heater 3, a power supply 5, a programmer 7 and a device 9 for controlling and / or measuring the electrical consumption of the electric radiator 3. The electric radiator 3 is supplied with electrical energy by the electrical supply source 5 with a phase conductor (terminal "L") while a neutral conductor (terminal "N") allows the return of the electrical current to the electrical supply source 5. The programmer 7 is arranged to control the electric radiator 3 via a pilot wire (terminal "FP").

[0008] 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 this end, device 9 has not only an input phase terminal L1 and an output phase terminal L2 but also an input neutral terminal NI and an output neutral terminal N2. The input terminal L1 and the output terminal L2 are generally connected to each other via a shunt that allows the electrical consumption of the electric radiator 3 to be measured.

[0009] The neutral input terminal NI 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.

[0010] Furthermore, in the example of [Fig. 1], several single-conductor electrical cables, six in total, are used to connect the device 9 to the electric heater 3, the power supply 5, and the timer 7, resulting in a complex and bulky wiring configuration. These single-conductor electrical cables could be replaced by a multi-conductor electrical cable, but in such a cable, the conductors all have the same diameter cross-section, and such dimensions do not take into account the difference in electrical current from one conductor to another. Oversizing represents a waste of material, particularly copper, in the manufacture of such a multi-conductor electrical cable.

[0011] The present invention improves the situation.

[0012] In this respect, the present invention relates to a heating system, comprising: • a heating installation comprising a heating element arranged to emit heat, an electrical power supply arranged to supply the heating element with electrical energy via a phase conductor, and a pilot wire terminal arranged to control the heating element via a 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.

[0013] The multi-conductor cable comprises, 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 for electrically interposing the intermediate device between the heating element and, respectively, the pilot wire terminal and the power supply.

[0014] The multi-conductor cable further includes a single neutral conductor for connecting 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.

[0015] 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.

[0016] Advantageously, the single neutral conductor of the multi-conductor cable has a cross-section strictly less than 1.5 mm2.

[0017] Preferably, the single neutral conductor of the multi-conductor cable has a cross-section strictly less than 0.75 mm2.

[0018] 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, and the input phase conductor and the output phase conductor each have a cross-section greater than or equal to 1.5 mm2.

[0019] In one or more embodiments, each conductor of the multi-conductor cable comprises copper.

[0020] In one or more embodiments, the multi-conductor cable includes a thermoplastic insulation sheath.

[0021] 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 by a wire clamp.

[0022] 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.

[0023] In one or more embodiments, the intermediate device includes a relay arranged to selectively control the power supply to the heating element by electrical energy by opening and closing a switch between the input phase conductor and the output phase conductor.

[0024] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings on which:

[0025] [Fig-1] illustrates a prior art wiring diagram of a control device and / or measuring the electrical consumption of a heating element with several single-conductor electrical cables;

[0026] [Fig.2] illustrates a wiring diagram, according to the invention, of a control device and / or measuring the electrical consumption of a heating element using a multi-conductor electrical cable; and

[0027] [Fig.3] illustrates a cross-sectional view of the multi-conductor electrical cable of [Fig.2].

[0028] Fig. 2 illustrates a wiring diagram of a heating system 1.

[0029] The heating system 1 can be installed in any type of dwelling to To improve domestic thermal comfort. Heating system 1 is arranged to transfer thermal energy to the dwelling according to a centralized program.

[0030] 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.

[0031] 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 Joule effect.

[0032] It is known to 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 in the lower region and an opening in the upper region. Cold air enters the lower region and is heated by contact with the electric heating element. The hot air, being less dense than the cold air, rises in the upper region and exits the metal box, while the cold air is replenished in the lower region.

[0033] The 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 present.

[0034] As another example, the electric radiator can also be a storage radiator comprising a refractory material for storing heat generated by electrical resistance. Typically, the electric radiator stores heat during off-peak hours and then releases the accumulated heat during peak hours.

[0035] Furthermore, the heating element 3 is arranged to adapt to a user's needs. The heating element 3 includes, for example, an interface for selecting an operating mode and a setpoint temperature. Such an interface constitutes a thermostat. The heating element 3 generally has at least four operating modes, named "comfort", "eco", "frost protection", and "off".

[0036] In "comfort" mode, the heating element 3 attempts to raise the room temperature to the setpoint temperature. In "eco" mode, the heating element 3 lowers the setpoint temperature, generally by 3 to 4°C, compared to "comfort" mode. The "frost protection" mode prevents the room temperature from falling below a minimum temperature—generally around 7°C—in case of prolonged absence, to avoid any risk of freezing, particularly in the pipes. Finally, the "off" mode turns off the heating element 3, thus preventing it from attempting to adjust the room temperature.

[0037] Furthermore, the 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.

[0038] The power supply 5 is arranged to supply the heating element 3 with electrical energy via phase conductor.

[0039] 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 by a phase conductor to supply the heating element 3 with an electric current. There is only one phase conductor here, and this is therefore 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.

[0040] The phase conductor and the neutral conductor can be distinguished by their color. For example, according to the international standard IEC 60445:2021, the phase conductor is brown, black or gray while the neutral conductor is blue.

[0041] 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.

[0042] In Europe, in a low-voltage distribution network, the voltage thus oscillates at a frequency of 50 hertz (Hz) between a maximum peak voltage of 320 volts (V) and a The minimum peak voltage is -320 volts (V), resulting in a peak-to-peak voltage of 640 volts (V). This oscillation yields an effective voltage of 230 volts (V). The effective value of an alternating voltage is the same as the value of a direct current voltage that produces the same heat output in an identical electrical resistance. Traditionally, multimeters and power line testers display the effective voltage. The peak voltage is rarely measured.

[0043] The programmer 7 is arranged to control the heating element 3 by pilot wire.

[0044] Pilot wire technology allows centralized and time-slot-based management of Several heating elements can be used to save energy or to specifically target off-peak hours to reduce costs. In the example in [Fig. 2], only one heating element 3 is shown. However, the heating system 1 can include several heating elements, all controlled by the same programmer 7.

[0045] The heating element 3 and the programmer 7 each have a pilot wire terminal FP for connecting the programmer 7 and the heating element 3 via a pilot wire. The programmer 7 can send a control signal to the heating element 3 in the form of a low-intensity electrical signal flowing through the pilot wire. The current in the pilot wire is typically less than 0.1 ampere (A).

[0046] In the example described here, the programmer 7 is a wall box 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.

[0047] The user interface 11 is arranged to allow the user to configure the programmer 7. The user can use the user interface 11 to program the operation of the heating element 3 in advance for each time slot. Daily programming consists of selecting, for each time slot of the day, the appropriate operating mode for the heating element 3.

[0048] For example, it is common for a user to select "comfort" mode for the times when they are present and "eco" mode for the times when they are absent. In the event of a prolonged absence, the user can program "frost protection" mode for the corresponding period.

[0049] Typically, the 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.

[0050] The screen 13 is arranged to display information relating to the heating element 3 and the selected programming. For example, the screen 13 displays the current operating mode of the heating element 3, the setpoint temperature corresponding to the "comfort" mode, or the programming for upcoming time periods, whether for daily use or for a prolonged absence.

[0051] The heating element 3, the power supply 5 and the programmer 7 form a heating installation of the heating system 1.

[0052] The device 9 is arranged to control and / or measure the electrical consumption of the heating element 3. To do this, the device 9 is connected to the heating installation by a multi-conductor cable 15. More specifically, the device 9 is electrically interposed between the heating element 3 and the electrical power supply 5.

[0053] 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.

[0054] 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.

[0055] Solutions other than the use of a shunt are known for measuring the electrical consumption of a heating element.

[0056] 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.

[0057] Relay 19 is for example an electromechanical relay comprising an electromagnet whose electrical supply results in the mechanical opening or closing of the switch by means of a paddle.

[0058] Solutions other than the use of a relay are known for controlling the electrical consumption of a heating element. For example, a pilot wire device can transmit a setpoint via the pilot wire to the heating element 3 independently of the setpoint transmitted by the programmer 7 to control the electrical load.

[0059] In the example of [Fig. 2], the device 9 is arranged both to measure and to control the electrical consumption of the heating element 3. However, the device 9 may be arranged only to measure or control the electrical consumption of the heating element 3.

[0060] Contrary to the prior art wiring diagram illustrated in [Fig. 1], the device 9 is connected to the heating installation by the multi-conductor cable 15 and not by several single-conductor cables.

[0061] The multi-conductor cable 15 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.

[0062] Typically, each conductor of the multi-conductor cable 15 comprises copper. Furthermore, the multi-conductor cable 15 may be protected by a thermoplastic insulating sheath. Such an insulating sheath is typically made from thermoplastic materials, such as polyvinyl chloride (better known by its English acronym "PVC") or polyethylene.

[0063] Advantageously, the multi-conductor cable 15 comprises only the five conductors mentioned above and therefore does not include any additional conductor.

[0064] 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 of [Fig. 2], 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 terminal thereof.

[0065] Furthermore, the input phase conductor LI allows the power supply 5 to supply the device 9 with electrical energy.

[0066] The input pilot wire conductor FPI and the output pilot wire conductor FPO allow the device 9 to be electrically interposed between the programmer 7 and the heating element 3. The input pilot wire conductor FPI is connected to the pilot wire terminal of the programmer 7 while the output pilot wire conductor FPO is connected to the pilot wire terminal of the heating element 3. Here again, the junction between the input pilot wire conductor FPI and the output pilot wire conductor FPO is made at the device 9.

[0067] It should be noted that the input pilot wire conductor FPI and the output pilot wire conductor FPO are generally independent of each other. In other words, the command received by the device 9 on the input pilot wire conductor The FPI setting is not necessarily reproduced on the FPO output pilot wire conductor. Device 9 can therefore impose a different setting on the FPO output pilot wire 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 setting.

[0068] Consequently, the 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.

[0069] The neutral conductor N9 allows the device 9 to be connected to the power supply 5. As explained previously, the device 9 is supplied with electrical energy by phase conductor, in this case the input phase conductor LI, so that the neutral conductor N9 allows the return of the electrical current to the power supply 5.

[0070] Whereas two neutral conductors are connected to device 9 in the prior art wiring diagram illustrated in [Fig.1], it is observed that only one neutral conductor, here referenced N9, is connected to device 9 in the wiring diagram illustrated in [Fig.2].

[0071] Unlike the prior art wiring diagram, the heating element 3 is connected by 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 of the electrical 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 only for the phase conductor and not for the neutral conductor.

[0072] As explained previously, a multi-conductor cable can be used in the prior art to connect the device 9 to the heating installation. 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.

[0073] 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 called a terminal junction box, further simplifies the wiring. Indeed, only one neutral terminal is then required on the power supply 5.

[0074] Fig. 3 illustrates a cross-sectional view of the multi-conductor cable 15.

[0075] More particularly, [Fig.3] shows a cross-section 23 of the multi-conductor cable 15 corresponding to its intersection with a plane orthogonal to the local direction of the multi-conductor cable 15.

[0076] Fig. 3 highlights the fact that, in addition to saving one conductor, the wiring scheme of Fig. 2 allows for resizing of conductors to achieve further copper savings.

[0077] 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).

[0078] 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, since it corresponds to the power consumption of device 9 alone.

[0079] The wiring diagram of [Fig.2] 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.

[0080] The neutral conductor N9 advantageously has a cross-section strictly less than 1.5 mm². Preferably, the neutral conductor N9 has a cross-section strictly less than 0.75 mm². The cross-section of the neutral conductor N9 can even be reduced to 0.5 mm².

[0081] The input phase conductor LI and the output phase conductor LO are traversed by a high-intensity electric current. Indeed, the input phase conductor LI supplies electrical energy to the device 9 and the heating element 3, while the output phase conductor LO supplies electrical energy to the heating element 3. Typically, the input phase conductor LI and the output phase conductor LO each have a cross-sectional area greater than or equal to 1.5 mm².

[0082] As explained previously, the control signal transmitted by the programmer 7 to the heating element 3 is a low-intensity electrical signal circulating in the pilot wire. Typically, the FPI inlet pilot wire conductor and the FPO outlet pilot wire conductor each have a cross-section strictly less than 1.5 mm². Advantageously, the FPI inlet pilot wire conductor and the FPO outlet pilot wire conductor can each have a cross-section strictly less than 0.75 mm², and even 0.5 mm².

[0083] The multi-conductor cable 15 therefore includes conductors with a dimension adapted to the intensity of the electric current, which allows savings in material, in particular copper, unlike a standard multi-conductor cable which includes conductors of the same dimension.

Claims

Demands

1. 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 (PF) 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 (IPC) and an output pilot wire conductor (OPC), and, on the other hand, an input phase conductor (IPC) and an output phase conductor (IPC) 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).

2. Heating system (1) according to claim 1, characterized in that the single neutral conductor (N9) of the multiconductor cable (15) has a cross-section strictly smaller than that of the neutral conductor (N3) at the output of the heating element (3).

3. Heating system (1) according to claim 1 or 2, characterized in that the single neutral conductor (N9) of the multiconductor cable (15) has a cross-section strictly less than 1.5 mm2.

4. Heating system (1) according to claim 3, characterized in that the single neutral conductor (N9) of the multiconductor cable (15) has a cross-section strictly less than 0.75 mm2.

5. Heating system (1) according to any one of the preceding claims, characterized in that the inlet pilot wire conductor (IPW) and the outlet pilot wire conductor (OPW) each have a cross-section strictly less than 1.5 mm2, and the inlet phase conductor (IPW) and the outlet phase conductor (IPW) each have a cross-section greater than or equal to 1.5 mm2.

6. Heating system (1) according to any one of the preceding claims, characterized in that each conductor of the multiconductor cable (15) comprises copper.

7. Heating system (1) according to any one of the preceding claims, characterized in that the multi-conductor cable (15) comprises a thermoplastic insulation sheath.

8. 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).

9. 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.

10. 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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