JP2015200462A - floor heating control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floor heating control device capable of distinguishing and specifying contact welding of relays, and insulation failure of a floor heater in occurrence of abnormality.SOLUTION: A floor heating control device 10 for controlling energization of a floor heater 101, includes a power source terminal 11 to which AC power is input from a single-phase three-line AC power source 100, a heater terminal 12 connected to the floor heater 101, and relays 21, 22 disposed on power lines LN1, LN2 connecting the power source terminal 11 and the heater terminal 12. The floor heating control device 10 includes a control portion 30 for keeping the relays 21, 22 in ON state by outputting ON signals to the relays 21, 22, and a detection sensor 32 for detecting electric current flowing in a detection line LN4.

Description

  The present invention relates to a floor heating control device.

  Conventionally, a floor heating control device that controls energization of a floor heating heater is known. For example, Patent Document 1 describes that a heater driving device used in an electric heater such as an electric cooking heater includes a relay and a detection unit that detects contact welding of the relay.

Japanese Patent Laid-Open No. 04-002078

  Here, in a floor heating control apparatus having a relay for switching on / off of energization of the floor heating heater, an abnormality such as contact welding of the relay or insulation failure of the floor heating heater may occur. In this case, the floor heating control device may want to specify whether the abnormality is relay contact welding or insulation failure of the floor heating heater.

  The object of the present invention has been made in view of the above-described circumstances, and is to provide a floor heating control device that can distinguish and identify relay contact welding and insulation failure of a floor heating heater when an abnormality occurs. is there.

  A floor heating control apparatus that achieves the above object controls energization of a floor heating heater, and is connected to a power supply terminal to which AC power is input from a single-phase three-wire AC power source and the floor heating heater. A heater terminal, a first power line and a second power line connecting the power supply terminal and the heater terminal, a first relay provided on the first power line, and a first relay provided on the second power line A connection line connecting two relays, a portion closer to the power supply terminal than the first relay in the first power line, and a portion closer to the power supply terminal than the second relay in the second power line; Two diodes provided on a line and connected in opposite directions to each other, a portion of the connection line connecting the two diodes, and the heater end more than the second relay in the second power line By detecting an ON signal to each of the relays, a detection line for connecting a close portion, a resistance provided on the detection line, a detection sensor for detecting a current flowing through the detection line, and each of the relays. A control unit that turns on a relay, and the control unit, based on the frequency of the current detected by the detection sensor in a situation where the ON signal is not output to each relay, It is determined whether insulation of a floor heater is defective or at least one contact weld of each relay.

  According to such a configuration, there is a high possibility that an abnormality has occurred when a current is detected by the detection sensor in a situation where the control unit does not output an ON signal to each relay. When the frequency of the current detected by the detection sensor is twice the frequency of the AC power, the abnormality is likely to be an insulation failure of the floor heater, while the frequency of the current detected by the detection sensor Is the same as the frequency of the AC power, it is highly possible that the abnormality is at least one contact weld of each relay. Thereby, based on the frequency of the current detected by the detection sensor, it is possible to distinguish and specify the insulation failure of the floor heater and at least one contact welding of each relay.

  The situation where no ON signal is output to each relay means, for example, the situation where an OFF signal is output to each relay to turn off each relay, or when each relay is a contact In this situation, no signal is output to each relay.

  About the said floor heating control apparatus, it is good to provide the switching element provided on the said detection line. According to this configuration, when the determination by the control unit is performed, the determination can be suitably performed by turning on the switching element. On the other hand, when the above determination is not performed, the voltage applied to the floor heating heater can be reduced by turning off the switching element. Thereby, the electric corrosion of a floor heater can be suppressed.

  In the floor heating control device, the detection sensor is a photocoupler having a light emitting element provided on the detection line, and the floor heating control device includes a shunt resistor connected in parallel to the light emitting element. It is good to have. According to such a configuration, the current flowing through the light emitting element is defined by the resistance value of the shunt resistor. Thereby, by adjusting the resistance value of the shunt resistor, the threshold current of the detection line that emits light from the light emitting element can be adjusted, and through this, detection variation of detection sensors and detection errors can be suppressed.

  According to the present invention, when an abnormality occurs, it is possible to distinguish and identify the relay contact welding and the insulation failure of the floor heater.

The circuit diagram which shows the electric constitution of a floor heating control apparatus. The circuit diagram which shows the flow of an electric current when the insulation failure of a floor heater has generate | occur | produced. (A) is a wave form diagram which shows a detection signal in case contact welding has occurred in the 2nd relay, and (b) is a waveform which shows a detection signal in case contact welding has occurred in the 1st relay. It is a figure, (c) is a wave form diagram which shows a detection signal when the insulation defect of the floor heating heater has generate | occur | produced. The flowchart which shows an abnormality monitoring process. (A) is a timing chart which shows the state of a switching element, (b) is a timing chart which shows the state of a 1st relay, (c) is a timing chart which shows the state of a 2nd relay. The circuit diagram which shows the floor heating control apparatus of another example.

Hereinafter, an embodiment of the floor heating control device will be described.
As shown in FIG. 1, the floor heating control device 10 electrically connects a single-phase three-wire AC power supply 100 and a floor heating heater 101. The floor heating control device 10 performs energization control of AC power to the floor heating heater 101.

  The floor heating control device 10 is connected to an AC power source 100, and a power source terminal 11 to which AC power is input from the AC power source 100, a heater terminal 12 connected to the floor heating heater 101, and a power source terminal 11 Two power lines LN1 and LN2 connecting the heater terminal 12 are provided.

  The floor heating control device 10 includes two relays 21 and 22 provided on two power lines LN1 and LN2. The first relay 21 is provided on the first power line LN1, and the second relay 22 is provided on the second power line LN2.

  Each of the relays 21 and 22 has an a contact. Specifically, each of the relays 21 and 22 is in an off state when no on signal is input, and is on when an on signal is input. When each of the relays 21 and 22 is in the on state, the AC power of the AC power supply 100 is transmitted to the floor heating heater 101 via the power lines LN1 and LN2, and the floor heating heater 101 is energized and heated. On the other hand, when each of the relays 21 and 22 is in the off state, the transmission of the AC power is interrupted, and the floor heating heater 101 is not energized.

  The floor heating control device 10 includes a control unit 30 that performs on / off control of the relays 21 and 22. When there is an energization start instruction by operating an operation panel (not shown) provided in the floor heating control device 10 or the like, the control unit 30 outputs an ON signal to each of the relays 21 and 22. Then, the relays 21 and 22 are turned on. On the other hand, when there is an energization stop instruction by operating the operation panel or the like, the control unit 30 outputs each of the relays 21 and 22 to an off state by outputting an off signal to the relays 21 and 22. .

  Here, since each of the relays 21 and 22 is a contact, each of the relays 21 and 22 is in a state where neither an on signal nor an off signal is input to the relays 21 and 22 (floating state). Is turned off. That is, the situation where no ON signal is input to each relay 21, 22 means that the OFF signal is input to each relay 21, 22 and the signal is input to each relay 21, 22. Including no situation.

In addition, the floor heating control apparatus 10 has the display part 31, and the control part 30 controls the display part 31 so that a desired display is performed as needed.
As shown in FIG. 1, the floor heater 101 is connected to the ground via an insulation resistor 102. Note that the capacitor 103 provided in parallel with the insulation resistor 102 is a stray capacitor that can naturally occur because the insulated floor heater 101 is laid on the ground.

  Here, in the configuration in which the relays 21 and 22 are provided as described above, contact welding may occur in the relays 21 and 22. In addition, insulation failure may occur in the floor heating heater 101. The poor insulation of the floor heater 101 means that the resistance value of the insulation resistance 102 becomes lower than a predetermined leakage threshold due to deterioration of the insulation resistance 102 or the like. In this case, even if each of the relays 21 and 22 is in an off state, a leakage current flows.

  On the other hand, the floor heating control device 10 of the present embodiment has a configuration for distinguishing and specifying the contact welding of the relays 21 and 22 and the insulation failure of the floor heating heater 101. The configuration will be described below.

  As shown in FIG. 1, the floor heating control device 10 includes a portion closer to the power supply terminal 11 than the first relay 21 in the first power line LN1 and a portion closer to the power supply terminal 11 than the second relay 22 in the second power line LN2. Is provided with a connection line LN3. On the connection line LN3, two diodes D1 and D2 connected in opposite directions are provided. Specifically, the anodes of the diodes D1 and D2 are connected to the power lines LN1 and LN2. The cathodes of the diodes D1 and D2 are connected to each other.

  The floor heating control device 10 includes a detection line LN4 that connects a portion of the connection line LN3 connecting the diodes D1 and D2 and a portion of the second power line LN2 closer to the heater terminal 12 than the second relay 22. ing. On the detection line LN4, a switching element SW, a resistor R1, and a detection sensor 32 that detects a current flowing through the detection line LN4 are provided.

  The switching element SW is normally off, for example, and is switched from an off state to an on state when an on signal is input. The specific configuration of the switching element SW is arbitrary such as a photocoupler, a relay, a transistor, or a MOSFET.

  The detection sensor 32 is, for example, a photocoupler, and includes a light emitting diode 32a as a light emitting element and a phototransistor 32b as a light receiving element. The light emitting diode 32a is provided on the detection line LN4 with the direction from the connection line LN3 toward the second power line LN2 as the forward direction. The phototransistor 32b is, for example, an npn type. The emitter terminal of the phototransistor 32b is connected to the ground, and the collector terminal is connected to the control power source 33 provided in the floor heating control device 10 and connected to the control unit 30 via the pull-up resistor R2. Yes. A signal from the collector terminal toward the control unit 30 is a detection signal of the detection sensor 32.

  Moreover, as shown in FIG. 1, the floor heating control apparatus 10 includes a shunt resistor R3 connected in parallel to the light emitting diode 32a. The resistance value of the shunt resistor R3 is set such that, for example, the light emitting diode 32a emits light when the current flowing through the detection line LN4 (specifically, the switching element SW or the resistor R1) exceeds a predetermined threshold current. ing.

  According to such a configuration, when a current equal to or higher than the threshold current does not flow through the detection line LN4, the detection signal is an HI signal. On the other hand, when a current greater than or equal to the threshold current flows through the detection line LN4, the light emitting diode 32a emits light, and the phototransistor 32b is turned on. As a result, the detection signal becomes a LOW signal. Thereby, the control part 30 can grasp | ascertain whether the electric current more than a threshold current is flowing into the detection line LN4.

  Here, the relationship between the waveform of the detection signal (the waveform of the current flowing through the detection line LN4) and the contact welding of the relays 21 and 22 and the insulation failure of the floor heater 101 will be described. For convenience of explanation, the switching element SW is turned on.

  First, the case where contact welding has occurred will be described. As shown by the one-dot chain line in FIG. 1, if the second relay 22 has contact welding, and the first relay 21 does not have contact welding (hereinafter simply referred to as (A)), A current flows through the path of the first diode D 1 → the switching element SW → the resistor R 1 → the light emitting diode 32 a → the second relay 22. Thereby, as shown to Fig.3 (a), a detection signal becomes a pulse waveform of the same frequency as the frequency f0 of the alternating current power input from the alternating current power supply 100. FIG.

  In addition, as shown by the two-dot chain line in FIG. 1, contact welding has occurred in the first relay 21 and contact welding has not occurred in the second relay 22 (hereinafter simply referred to as (B)). The current flows through the path of the second diode D 2 → the switching element SW → the resistor R 1 → the light emitting diode 32 a → the floor heating heater 101 → the first relay 21. Thereby, as shown in FIG. 3B, the detection signal becomes a pulse waveform having the same frequency as the frequency f0 of the AC power input from the AC power supply 100.

The detection signal in the case of (A) and the detection signal in the case of (B) are shifted in phase by π.
Next, the case where the insulation failure of the floor heater 101 has occurred will be described. As shown in FIG. 2, when an insulation failure occurs in the floor heating heater 101, the current flows through the path of the first diode D 1 → the switching element SW → the resistance R 1 → the light emitting diode 32 a → the floor heating heater 101 → the insulation resistance 102. Flowing. Furthermore, a current flows through a path of the second diode D 2 → the switching element SW → the resistor R 1 → the light emitting diode 32 a → the floor heating heater 101 → the insulation resistance 102. As a result, as shown in FIG. 3C, the detection signal becomes a pulse waveform having a frequency twice the frequency f0 of the AC power input from the AC power supply 100. That is, the frequency f of the detection signal is different between when the insulation failure of the floor heater 101 occurs and when the contact welding of the relays 21 and 22 occurs.

  The control unit 30 determines whether or not an abnormality has occurred based on the detection signal of the detection sensor 32 at the time of power-on, before the start of energization of the floor heating heater 101, and after the end of energization of the floor heating heater 101, and If an abnormality has occurred, an abnormality monitoring process for identifying the cause is executed. The abnormality monitoring process will be described below.

  As shown in FIG. 4, first, in step S101, the control unit 30 outputs the ON signal to the switching element SW, thereby switching the switching element SW from the OFF state to the ON state.

  Thereafter, in step S <b> 102, the control unit 30 outputs an off signal to each of the relays 21 and 22. In subsequent step S103, the control unit 30 determines whether or not a current equal to or greater than the threshold current flows through the detection line LN4 based on the detection signal of the detection sensor 32. The process in step S103 corresponds to an abnormality determination process for determining whether an abnormality has occurred.

  Here, an OFF signal is output to each of the relays 21 and 22 under the condition that the contact welding of each of the relays 21 and 22 has not occurred and the insulation failure of the floor heater 101 has not occurred. In this case, no current is detected by the detection sensor 32. Therefore, when no current is detected in step S103 (when the detection signal is always a HI signal), no abnormality has occurred. In this case, in step S104, the control unit 30 switches the switching element SW from the on state to the off state, and ends the abnormality monitoring process.

  In the abnormality monitoring process executed before the energization of the floor heating heater 101 is started, after the energization of the floor heating heater 101 is started, in detail, after an ON signal is output to each of the relays 21 and 22. The process of step S104 is executed.

  On the other hand, in the case where a current is detected by the detection sensor 32 in spite of outputting an OFF signal to each of the relays 21 and 22 (when the detection signal has a periodic pulse waveform), each relay There is a high possibility that contact welding has occurred in at least one of 21 and 22, or that an insulation failure of the floor heater 101 has occurred. In this case, the control unit 30 proceeds to step S105 and grasps the frequency f of the detection signal as the frequency of the current detected by the detection sensor 32.

  In subsequent step S106, the control unit 30 determines whether or not the frequency f of the detection signal is twice the frequency f0 of the AC power input from the AC power supply 100. The frequency f0 of AC power may be stored in a predetermined storage area of the control unit 30 as a known value (for example, 50 Hz or 60 Hz), or may be measured.

  As already described, the frequency f of the detection signal may vary depending on the cause of the abnormality. For this reason, if attention is paid to the fact that the cause of the abnormality can be specified based on the frequency f of the detection signal, it can be said that the process of step S106 is an abnormality factor specifying process for specifying the cause of the abnormality.

  When the frequency f of the detection signal is twice the frequency f0 of the AC power, there is a high possibility that the floor heater 101 is poorly insulated. Therefore, when the frequency f of the detection signal is twice the frequency f0 of the AC power, the control unit 30 executes an insulation failure handling process corresponding to the insulation failure of the floor heating heater 101 in step S107. This abnormality monitoring process is terminated. In the insulation failure handling process, for example, the control unit 30 switches the switching element SW from the on state to the off state. And the control part 30 controls the display part 31 so that the display to the effect that the insulation failure of the floor heating heater 101 has occurred is performed, or outputs an ON signal to each of the relays 21 and 22. Or ban.

  On the other hand, when the frequency f of the detection signal is the same as the frequency f0 of the AC power, there is a high possibility that contact welding has occurred in at least one of the relays 21 and 22. For this reason, when the frequency f of the detection signal is the same as the frequency f0 of the AC power, the control unit 30 executes a contact welding corresponding process corresponding to the contact welding in step S108, thereby performing the abnormality monitoring process. Exit. In the contact welding handling process, for example, the control unit 30 switches the switching element SW from the on state to the off state. And the control part 30 controls the display part 31 so that the display to the effect that the contact welding has generate | occur | produced in at least one of each relay 21 and 22 is performed, or it is ON signal with respect to each relay 21 and 22 Is prohibited.

  That is, the switching element SW switches from the off state to the on state when the abnormality determination process is executed. When it is determined that there is no abnormality in the abnormality determination process, the switching element SW is switched from the on state to the off state when the abnormality determination process ends, while it is determined that there is an abnormality in the abnormality determination process. In such a case, the on-state is switched to the off-state after execution of the abnormality factor specifying process in step S106.

Next, the operation of this embodiment will be described.
When a current is detected by the detection sensor 32 in a situation where an off signal is input to each of the relays 21 and 22, it is determined that an abnormality has occurred. Then, based on the frequency f of the detection signal output from the detection sensor 32, it is determined whether the abnormality is welding of at least one of the relays 21 and 22 or an insulation failure of the floor heater 101.

Next, the timing at which abnormality determination is performed and the on / off states of the switching element SW and the relays 21 and 22 will be described.
As shown in FIG. 5, power is turned on at timing t0. Thereafter, as shown in FIG. 5A, the switching element SW is switched from the OFF state to the ON state at the timing t1, and the abnormality determination process in step S103 is performed at the timing t2. And when it determines with there being no abnormality in the said abnormality determination process, switching element SW switches from an ON state to an OFF state at the timing of t3.

  Thereafter, when an energization start instruction is given, as shown in FIG. 5A, the switching element SW is turned on at the timing t4, and the abnormality determination process is executed at the timing t5. If it is determined in the abnormality determination process that there is no abnormality, as shown in FIGS. 5B and 5C, the relays 21 and 22 are turned off at the timing t6. Switch to the on state. Thereafter, the switching element SW is switched from the on state to the off state (see FIG. 5A).

  When an energization stop instruction is given at the timing t7, as shown in FIGS. 5B and 5C, the relays 21 and 22 are switched from the on state to the off state. Then, as shown in FIG. 5A, the switching element SW is switched from the off state to the on state. Thereafter, the abnormality determination process is executed at the timing of t8, and when it is determined that there is no abnormality in the abnormality determination process, the switching element SW is switched from the ON state to the OFF state at the timing of t9. That is, the switching element SW is turned on when the abnormality determination process is performed, while the switching element SW is in a standby period from when the power is turned on until the energization of the floor heating heater 101 is started, or during the energization period of the floor heating heater 101. Some are off.

According to the embodiment described above in detail, the following effects are obtained.
(1) The floor heating control device 10 includes a power supply terminal 11 to which AC power is input from a single-phase three-wire AC power supply 100, a heater terminal 12 connected to the floor heating heater 101, a power supply terminal 11 and a heater terminal. 12 are provided with two power lines LN1 and LN2. On the two power lines LN1 and LN2, relays 21 and 22 for switching on / off of energization of the floor heating heater 101 are provided.

  In such a configuration, the floor heating control device 10 is provided on the connection line LN3 and the connection line LN3 that connect portions closer to the power supply terminal 11 than the relays 21 and 22 in the power lines LN1 and LN2, and are connected in directions opposite to each other. The two diodes D1, D2 are provided. And the floor heating control apparatus 10 is provided with the detection line LN4 which connects the connection part of each diode D1, D2 in the connection line LN3, and the part nearer to the heater terminal 12 than the 2nd relay 22 in the 2nd power line LN2. Yes. The floor heating control device 10 includes a resistor R1 provided on the detection line LN4 and a detection sensor 32 that detects a current flowing through the detection line LN4. And the floor heating control apparatus 10 is provided with the control part 30 which makes each said relay 21 and 22 ON state by outputting an ON signal with respect to each relay 21 and 22. FIG. The control unit 30 insulates the floor heating heater 101 based on the frequency f of the detection signal, which is the frequency of the current detected by the detection sensor 32, in the situation where the ON signal is not output to each of the relays 21 and 22. An abnormal factor specifying process (the process of step S106) for determining whether the relay is defective or at least one contact weld of each of the relays 21 and 22 is executed. Accordingly, when an abnormality occurs, it is possible to distinguish and specify the insulation failure of the floor heater 101 and the contact welding of at least one of the relays 21 and 22, so that the subsequent measures such as replacement of parts are preferably performed. It can be carried out.

  (2) Specifically, the control unit 30 determines whether an abnormality has occurred based on the detection result of the detection sensor 32 in a situation where no ON signal is output to each of the relays 21 and 22. The abnormality determination process to be performed (the process of step S103) is executed. In the abnormality determination process, the control unit 30 determines that an abnormality has occurred when a current is detected by the detection sensor 32. In this case, the control unit 30 grasps the frequency f of the detection signal and, when the frequency f is twice the frequency f0 of the AC power, determines that the abnormality is an insulation failure of the floor heating heater 101. When the frequency f of the detection signal is the same as the frequency f0 of the AC power, it is determined that the abnormality is at least one contact welding of the relays 21 and 22. Thereby, the presence or absence of abnormality and the cause of the abnormality can be specified.

  (3) The floor heating control device 10 includes a switching element SW provided on the detection line LN4. As a result, when the abnormality determination process or the abnormality factor identification process is executed, the switching element SW is turned on. On the other hand, when the abnormality determination process or the abnormality factor identification process is not executed, the switching element SW is turned off. By doing so, the electric corrosion of the floor heater 101 can be suppressed.

  More specifically, if there is no switching element SW or the switching element SW is always on, a voltage is applied to the floor heating heater 101 even if each of the relays 21 and 22 is off. For this reason, the floor heater 101 is easily eroded.

  On the other hand, when the switching element SW is in the OFF state, a voltage is applied to the switching element SW, so that the voltage applied to the floor heating heater 101 is reduced. Thereby, the electric corrosion of the floor heating heater 101 can be suppressed.

  (4) The detection sensor 32 is a photocoupler having a light emitting diode 32a provided on the detection line LN4, and the floor heating control device 10 includes a shunt resistor R3 connected in parallel to the light emitting diode 32a. ing. Thereby, the current flowing through the light emitting diode 32a is defined by the resistance value of the shunt resistor R3. Therefore, by adjusting the resistance value of the shunt resistor R3, the threshold current of the detection line LN4 that emits light from the light emitting diode 32a can be adjusted. Therefore, it is possible to suppress the detection variation of the detection sensor 32 and the erroneous detection.

In addition, you may change the said embodiment as follows.
As shown in FIG. 6, the floor heating control device 10 is closer to the heater terminal 12 than the first relay 21 in the first power line LN1 and closer to the heater terminal 12 than the second relay 22 in the second power line LN2. A second connection line LN5 that connects the parts, and a third diode D3, a resistor R4, and a second detection sensor 40 provided on the second connection line LN5 may be provided. In this case, the control unit 30 determines whether one of the relays 21 and 22 is welded or both of the relays 21 and 22 are welded based on the detection results of the detection sensors 32 and 40. Also good.

  The detection line LN4 is connected to the second power line LN2, but is not limited thereto, and may be connected to a portion closer to the heater terminal 12 than the first relay 21 in the first power line LN1.

  The control unit 30 may be configured to determine whether the contact of the first relay 21 or the contact of the second relay 22 is welded based on the phase of the current detected by the detection sensor 32. In this case, for example, the floor heating control device 10 includes a detection circuit that detects a zero-cross signal that is in phase with the detection signal when contact welding has occurred in the second relay 22, and the control unit 30 includes the zero-cross signal. It is good to be able to grasp. When the detection signal output from the detection sensor 32 and the zero cross signal are in phase, the control unit 30 determines that the contact of the second relay 22 is welded. If the phase of the detection signal and the zero cross signal is shifted by π), it is determined that the contact of the first relay 21 is welded. If the zero cross signal can be detected, the specific configuration of the detection circuit is arbitrary.

(Circle) the control part 30 may determine whether the frequency f of a detection signal is the same as the frequency f0 of alternating current power as a process of step S106.
The switching element SW may be omitted or the shunt resistor R3 may be omitted.

  ○ The execution timing of the abnormality monitoring process is not limited to when the power is turned on or before and after the floor heater 101 is energized. For example, the abnormality monitoring process is periodically executed during a standby period (for example, the period from the timing t3 to the timing t4). May be.

The specific configuration of the detection sensor 32 is arbitrary as long as the current flowing through the detection line LN4 can be detected.
The period during which the switching element SW is in an off state is arbitrary. For example, the switching element SW may be in an off state only during a standby period, or the energization period of the floor heating heater 101 (the period from the timing t6 to the timing t7) ) May be turned off only during.

Next, a preferable example that can be grasped from the embodiment and another example will be described below.
(A) The control unit includes an abnormality determination unit that determines that an abnormality has occurred when a current is detected by the detection sensor in a situation where an ON signal is not output to each relay, and the abnormality determination When it is determined that an abnormality has occurred by the part, it is determined whether the abnormality is an insulation failure of the floor heating heater or at least one contact welding of each relay based on the frequency of the current detected by the detection sensor Good.

  (B) The switching element is switched from the OFF state to the ON state when the determination by the abnormality determination unit is performed, whether the determination by the abnormality determination unit, or the insulation failure of the floor heater or the contact welding of at least one of the relays When the determination is completed, the on state may be switched to the off state.

  (C) The control unit may determine whether the contact welding of the first relay or the contact welding of the second relay is based on the phase of the current detected by the detection sensor.

  DESCRIPTION OF SYMBOLS 10 ... Floor heating control apparatus, 11 ... Power supply terminal, 12 ... Heater terminal, 21, 22 ... Relay, 30 ... Control part, 32, 40 ... Detection sensor, 32a ... Light emitting diode, 32b ... Phototransistor, 100 ... Single phase 3 Linear AC power source, 101 ... floor heating heater, 102 ... insulation resistance, D1, D2 ... diode, LN1, LN2 ... power line, LN3 ... connection line, LN4 ... detection line, SW ... switching element, R1 ... resistance, R3 ... Shunt resistance.

Claims (3)

A floor heating control device for controlling energization of a floor heating heater,
A power supply terminal to which AC power is input from a single-phase three-wire AC power supply;
A heater terminal connected to the floor heating heater;
A first power line and a second power line connecting the power supply terminal and the heater terminal;
A first relay provided on the first power line; and a second relay provided on the second power line;
A connection line connecting a portion closer to the power supply terminal than the first relay in the first power line and a portion closer to the power supply terminal than the second relay in the second power line;
Two diodes provided on the connection line and connected in opposite directions;
A detection line that connects a portion of the connection line connecting the two diodes and a portion of the second power line closer to the heater terminal than the second relay;
A resistor provided on the detection line;
A detection sensor for detecting a current flowing in the detection line;
A controller that turns each relay on by outputting an ON signal to each relay;
With
In the situation where the ON signal is not output to each of the relays, the control unit determines whether the floor heating heater has an insulation failure based on the frequency of the current detected by the detection sensor, or at least each of the relays. A floor heating control device that determines whether one of the contacts is welded.   The floor heating control device according to claim 1, further comprising a switching element provided on the detection line. The detection sensor is a photocoupler having a light emitting element provided on the detection line,
The floor heating control device according to claim 1, wherein the floor heating control device includes a shunt resistor connected in parallel to the light emitting element.