JPH1183056A - Load switchgear for embedding-type electric heating facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load switchgear for a flush electric heating facility which does not let the electric heater of the flush electric heating facility generate heat in case that the contact of a load switch fuses. SOLUTION: This load switchgear possesses a load switch 13 which is interposed between an electric heater 2 being buried together with a temperature detector 3 in concrete floor 1 and a power source, a temperature fuse 14 which is connected in series to the contacts 13a and 13b installed at this switch 13d, an indirect heater 15 for fusion which is arranged near the fuse 14, a contact open/close condition detecting circuit 16 and a fusion detecting circuit 17 which detect the fusion of the contacts 13a and 13b, and a fuse fusion circuit 18 which is connected to the output end of the detecting circuit 17 and allows the current application to the indirect heater 15, according to the output signal from the circuit 17 at the time of having detected the fusion. As a result, the heat generation of the electric heater 2 is stopped by fusing the temperature fuse 14 when it has electrically detected the fusion of the contacts 13a and 13b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floor heating system for heating a floor with an electric heater embedded in a concrete floor of, for example, a gymnasium or a public hall. The present invention relates to an embedded heating facility which is used as a snow melting facility such as a road surface which melts snow by providing an electric heater embedded in a cast-in balcony or the like, and more particularly to the heating facility for supplying electricity to and disconnecting electricity from the electric heater. The present invention relates to a load switchgear provided in a vehicle.

[0002]

2. Description of the Related Art An ordinary electric floor heating system applied as a heating system for a general house detects the temperature of the floor heated by an electric heater embedded in the floor with a temperature detector and detects the temperature. In addition to controlling the amount of electricity supplied to the electric heater by the electric temperature control device based on the obtained temperature information, a large number of bimetals are attached in series to the electric heater similarly to an electric carpet or the like. Usually, about 12 bimetals are used per tatami mat. When an electric kotatsu or cushion is placed on the floor due to their use and the temperature of the part becomes abnormally high, the bimetal contact at the corresponding point that detects that temperature is opened and the power to the electric heater is cut off. In such a way that the abnormally high temperature condition does not continue.

On the other hand, in an embedded electric heating system in which an electric heater is embedded in a concrete floor portion of a gymnasium or a public hall, a road floor portion, or the like to perform floor heating or snow melting on a road surface, the heating area is large. Since the surface temperature is also low, it is uneconomical to provide multiple thermostats that operate independently of the temperature controller to address local overheating. In addition, for example, in a concrete embedded electric floor heating facility, a heat capacity of a heated portion such as a floor in which an electric heater is embedded is large, and local overheating is unlikely to occur. Therefore, a thermostat is not conventionally used.

[0004] Under such circumstances, in a conventional embedded type heating equipment provided with an electric heater embedded in a concrete floor or the like, the temperature of a heated portion such as the concrete floor is managed based on temperature information detected by a temperature detector. It is done with a temperature control device.

By the way, the control current capacity that the temperature control device can handle is fixed. On the other hand, the area to be heated such as the concrete floor where the electric heater is embedded is large,
The control current capacity may be exceeded. In such a case, a load switching device having a large load current capacity is added and used in combination with a temperature control device.

That is, the load switching device includes a load switch interposed between the electric heater and the power supply, and opens and closes the heater circuit by the load switch based on a control signal output from the temperature control device. Electric power is supplied to and cut off from the electric heater. The load switch, which opens and closes its contacts by an electromagnetic solenoid, holds the contacts in a closed state without exciting the electromagnetic solenoid when the temperature of the heated part is lower than the set temperature set by the temperature control device, When the temperature of the heated portion is higher than the set temperature, the electromagnetic solenoid is excited to open the contact.

[0007] When a load switchgear having a large load current capacity is added to an existing embedded electric heating equipment, it is not necessary to perform a large-scale work on the equipment itself, and moreover, as described above, a large number of equipments are required. Without providing the thermostat, the load switching device can be operated by the control signal of the temperature control device, and power can be supplied to and cut off from the electric heater embedded in the portion to be heated such as the concrete floor.

[0008]

Since a large load current of 100 V or 200 V flows through the load switching device, the contact of the load switch that opens and closes this current path generates an arc with the switching. This may cause the contacts to be welded. However, conventionally, no countermeasures have been taken against such welding of the contacts, so that the welding makes temperature control impossible. In such a case, for example, in a floor heating system, the temperature of the concrete floor is excessively increased by the electric heater that continues to generate heat, and the surface temperature of the finishing material on the floor unnecessarily increases, which causes discomfort to a person on the floor. In addition to the above, there is a problem that the insulation performance of the insulation coating of the electric heater is deteriorated, and the electric power is increased due to unnecessary power consumption of the electric heater.

Accordingly, a first problem to be solved by the present invention is to provide a load switch for an embedded electric heating facility that prevents the electric heater of the embedded electric heating facility from generating heat when the contacts of the load switch are welded. To get the equipment.

In the prior art, if the contacts of the load switch are welded as described above, there is no way to know that the contacts are welded, so it is difficult to employ quick countermeasures for failure of the load switch. In particular, in the case where a plurality of embedded electric heating facilities are provided side by side according to the size of the portion to be heated, it cannot be easily known which load switch of which load switching device has failed.

Accordingly, a second object of the present invention is to provide an embedded electric heating system capable of easily notifying the failure due to welding of the contacts of the load switch while solving the first problem. To obtain a load switchgear.

[0012]

In order to solve the above-mentioned first problem, an invention according to a first aspect of the present invention is to interpose an electric heater between a power supply and an electric heater which is embedded in a portion to be heated together with a temperature detector. Load switch, a temperature fuse connected in series to a contact included in the switch, a fusing indirect heater disposed near the fuse, and detecting welding of the contact of the load switch. Welding detection means, and fuse blowing means connected to an output end of the welding detection means and allowing current to the indirectly heated heater according to a fusing detection signal output from the welding detection means when the welding is detected. It is provided.

According to the first aspect of the present invention, when the contact of the load switch is welded, the welding detecting means detects the welding and supplies an output signal (fusing detection signal) to the fuse blowing means. Then, energization of the indirectly heated heater is permitted by the fusing means, and the heater generates heat. The heat fuses the thermal fuse in series with the contact. When the contact of the load switch is welded in this way, the thermal fuse is blown based on the detection, so that the power to the electric heater embedded in the heated portion is supplied through the load switch of the present invention. Can be forcibly released.

[0014] In order to solve the second problem, the invention according to claim 2 according to claim 1 is characterized in that display means is connected to an output end of the welding detection means, and the welding is performed when the welding is detected. The display means has a display element that keeps a display state until the power is turned off after the display operation is started in response to the fusing detection signal output from the detection means.

Since the second aspect of the present invention is dependent on the first aspect of the present invention, in addition to the operation of the first aspect, the display means receives a fusing detection signal output from the welding detecting means to open and close the load. Display that the contacts of the
Since the electric display element for performing this display keeps the display state until the power is turned off after the start of the display operation, it is possible to easily notify the failure of the load switch including the welding of the contacts.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As an example of the embedded electric heating apparatus, the concrete embedded electric floor heating equipment shown in FIG. 1 is provided in parallel with one or two or more as shown in FIG. In addition, the code | symbol A has shown the electric floor heating equipment installed in the near side in FIG. 1, and B has shown the other electric floor heating equipment installed adjacent to the said equipment A and the back side in FIG.

The two facilities A and B both having the same structure
Is an electric heater 2 embedded in a concrete floor 1
And a temperature detector 3 similarly embedded, and an operation panel 4 mounted above the floor 1, for example, on a wall rising from the floor 1. The concrete floor 1 as a floor heating load, that is, a heated portion, has a heat insulating material 6 laid on concrete 5 and a first mortar 7 for holding down on the heat insulating material 6.
And a second mortar 8 for finishing is further laid on the first mortar 7, and a finishing material 9 is laid on the second mortar 8.

The electric heater 2 and the temperature detector 3 are embedded between the first and second mortars 7 and 8. As the electric heater 2, a resistance heating wire formed by covering a heating wire for generating resistance heating with an insulating coating is used, which is provided in a meandering shape so as to be located over substantially the entire area of the arrangement as shown in FIG. Have been. Floor heating is performed by radiant heat radiated by the heat generated by the electric heater 2, and the heater circuit is not provided with a bimetal that detects local overheating and opens the heater circuit.

The operation panel 4 individually provided in each of the floor heating facilities A and B has an operation surface on the front surface, and is provided with various operation elements and display windows (not shown). The heating temperature of the electric heater 2 is arbitrarily set via a child. Each of these operation panels 4 includes an electric temperature control device 11 and a load switching device 12
Is built-in.

As shown in FIG. 2, in the temperature control device 11, the temperature specified by the operator is set as a threshold value, and the temperature information of the concrete floor 1 detected by the temperature detector 3 is stored. Supplied. This control device 11
Outputs a control signal for causing the electric heater 2 to generate heat when the temperature value related to the supplied temperature information is equal to or lower than the threshold value (in other words, when the temperature of the concrete floor 1 is equal to or lower than the set temperature), The temperature value according to the supplied temperature information exceeds the threshold value (in other words, the concrete floor 1
If the temperature exceeds the set temperature), the electric heater 2
The control signal for stopping the heat generation is output. The control signal includes, but is not limited to, an AC voltage signal using the power supply voltage as it is, or, for example, 1V to 4V.
An 8 V DC voltage signal or the like can be used.

The load switchgear 12 has a large floor heating area,
Therefore, when the usage amount of the electric heater 2 embedded therein is large and exceeds the control current capacity of the temperature control device 11, the electric heater 2 is added to the operation unit 4. As shown in FIG. 2, the load switchgear 12 includes a load switch 13, a temperature fuse 14, an indirect heater 15, a contact open / closed state detection circuit 16, a welding detection circuit 17, and a fuse welding circuit 18
And a display circuit 19 as display means.

The load switch 13 comprises an electromagnetic solenoid and a relay circuit having normally closed contacts 13a and 13b which are opened when the solenoid is excited. The load switch 13 has its contacts 13 a and 13 b connected to the electric heaters 2 and 1.
It is interposed between a power supply of 00 V and 200 V, and is provided to carry out power supply to the heater circuit and disconnection by opening and closing the power supply. The load switch 13 is connected to the temperature control device 1.
In the case where the control signal supplied from the control device 11 is a control signal for causing the electric heater 2 to generate heat, the electromagnetic solenoid is de-energized (OFF) and the contacts 13a and 13b are closed. If the control signal supplied from the control device 11 is a control signal for stopping the heat generation of the electric heater 2, the electromagnetic solenoid is excited (ON) to open the contacts 13a and 13b. Has become.

The thermal fuse 14 is provided in series with one contact, for example, the contact 13a. Indirect heat heater 1
5 uses a resistor, which is connected to the thermal fuse 14.
Is disposed in the vicinity of. The heater 15 may be provided in contact with the temperature fuse 14 or may be arranged close to a state where heat conduction is good.

The contact open / close state detecting circuit 16 connects one of the pair of input terminals to one end of the electric heater 2 and one contact 13a.
And the other input end is connected between the other end of the electric heater 2 and the other contact 13b. The detection circuit 16 is a circuit that detects whether the contacts 13a and 13b are in a closed state or an open state. For example, a voltage reading unit that reads a voltage between C and D in FIG. And a voltage determining unit for determining the voltage between C and D to detect the voltage between the contacts C and D.
13b to determine the open / closed state. That is, the voltage between C and D is zero when the contacts 13a and 13b are open, while the voltage between C and D is equal to the power supply voltage when the contacts 13a and 13b are closed. The contact points 13a and 13b are determined by reading and determining the voltage level.
Can be determined.

The welding detecting circuit 17 which forms the welding detecting means 20 in cooperation with the detecting circuit 16 comprises a two-input AND circuit, and a detection signal output from the detecting circuit 16 is supplied to one input terminal. The control signal output from the temperature controller 11 is supplied to the other input terminal. The condition for satisfying the AND condition of the welding detection circuit 17 is as follows. When the detection circuit 16 detects the closed state of the contacts 13a and 13b, the detection signal supplied from the circuit 16 and the electric heater 2 supplied from the temperature control device 11 It is established when the control signal for stopping the heat generation coincides with the control signal. Thereby, it is determined that the contacts 13a and 13b are welded. This welding determination is based on the contact closed state in the normal switching operation of the load switch 13 by the contacts 13a and 13b.
Of the contact 13 in a normal state so as not to be mistaken for welding.
The condition is set when the AND condition continues to be satisfied for a time longer than the contact closing time of the contacts a and 13b. For this purpose, the welding detection circuit 17 has a timer circuit for measuring a preset time limit from the time when the AND condition is satisfied, and when the AND condition continues to be satisfied after the time limit has elapsed, welding is performed. A detection signal is output.

A fuse blowing circuit 18 and a display circuit 19 are connected to the output terminal of the welding detecting means 20, in other words, to the output terminal of the welding detecting circuit 17, respectively. The fuse blowing circuit 18 has a normally open switching element 18a that always keeps the open state, and supplies a fusing detection signal output from the fusing detection circuit 17 when the fusing detection circuit 17 detects the fusing. During this operation, the switching element 18a is closed. The switching element 18a and the indirect heater 15 are connected in series, and are connected to the power supply line. Therefore, when the switching element 18a is closed, a current flows to the indirect heater 15.

The display circuit 19 includes an electric display element 19a such as a light emitting diode, and the light emitting state thereof can be visually recognized through a display window on the front of the operation panel 4. The display circuit 19 performs a display operation of the display element 19a by supplying a welding detection signal output from the welding detection circuit 17 when the welding detection circuit 17 detects the welding, and furthermore, a display state until the power is turned off. Is to be held. For this purpose, for example, a self-holding circuit is provided as a memory function unit that keeps supplying power to the display element 19a. As a display operation of the display element 19a, lighting or blinking of a light emitting diode or the like, or extinguishing of a light emitting diode or the like which is in a lighting state during normal use can be adopted.

In the normal operation of the side-by-side concrete embedded electric floor heating facilities A and B, when the concrete floor 1 is lower than a predetermined temperature, the concrete floor 1 is supplied from a temperature detector 3 for detecting the temperature. The temperature control device 11 outputs a control signal for keeping the contacts 13a and 13b of the load switch 13 of the load switch device 12 in a closed state in accordance with the detected temperature information. Thereby, the heat generation of the electric heater 2 is continued, the radiant heat is applied from inside the concrete floor portion 1, and the floor heating is continued. In this case, the contact opening / closing state detection circuit 16 detects that the contacts 13a and 13b are in the closed state, and supplies a detection signal to the welding detection circuit 17. At this time, the temperature control device 11 still supplies the contact 13a, Since the control signal for closing 13b is output, the AND condition is not satisfied in the welding detection circuit 17, and the fuse blowing circuit 18 and the display circuit 19 do not operate.

When the temperature detector 3 detects that the concrete floor 1 has reached a predetermined temperature by continuing the floor heating, the temperature control device 11 receives the temperature detection signal and opens the contacts 13a and 13b. Since the control signal is output, the contacts 13a and 13b of the load switch 13 are opened, and the heat generation of the electric heater 2 is stopped. In this case, the contact opening / closing state detection circuit 16 detects the open state of the contacts 13a and 13b and supplies the detection signal to the welding detection circuit 17, so that the temperature control device 11 still operates the contacts 13a and 13b.
Despite the output of the control signal for opening 3b, the welding detection circuit 17 to which the output signal of the contact opening / closing state detection circuit 17 and the control signal of the temperature control circuit 11 are supplied may satisfy the AND condition. Absent.

However, the contact 13 of the load switch 13
When a and 13b are welded by a spark or the like, the temperature of the concrete
1 outputs a control signal to open the contacts 13a and 13b, while the contact open / closed state detection circuit 17 detects that the contacts 13a and 13b are closed.
An AND condition is satisfied in the welding detection circuit 17 to which signals from these are supplied. That is, the welding detection means 20 of the load switching device 12 determines that the contacts 13 a and 13 b have been welded, and supplies a fusing detection signal to the fuse blowing circuit 18 and the display circuit 19 from the output terminal of the welding detection circuit 17.

As a result, in the fuse blowing circuit 18, the switching element 18a is changed from the open state to the closed state to enable the energization of the indirect heater 15, so that the heater 15 generates heat and is connected in series with the contact 13a. The connected thermal fuse 14 is blown. Therefore, the load switch 13
Power supply to the electric heater 2 is cut off through
Since the temperature of the concrete floor 1 rises more than necessary after the power is cut off, it does not cause any discomfort to the people on the floor 1 or cause deterioration of the insulation coating of the electric heater 2 and the electric power. The heater 2 does not generate heat unnecessarily to increase the electricity cost.

In conjunction with such an operation, in the display circuit 19 to which the fusing detection signal is supplied, the display element 19a is displayed based on the supply. , 13b
Can be notified that welding has occurred. Therefore, recovery measures can be taken promptly based on the visual recognition.

Further, such a display operation is performed by the floor heating equipment A or B having the contacts 13a and 13b where the welding has occurred.
And the display is continued until the power is turned off. Therefore, at least one of the floor heating facilities A and B in which the fusing has occurred can be easily identified by this display, so that the facility can be restored, that is, the corresponding operation panel 4 is opened and the load switch 13 and the temperature fuse 14 are opened. Exchange measures can be taken promptly.

By the way, in the absence of such a display structure, a user or the like can sense that some abnormality has occurred due to the phenomenon that the concrete floor 1 does not warm up, but the floor heating area is large and a plurality of electric floor heatings are required. Under the condition that the equipment is installed, it is necessary for the contractor who installed the floor heating to check the operation panel 4 corresponding to each equipment one by one in order to find the operation panel corresponding to the area that does not warm up based on the design and construction drawing. There is. In addition, this inspection work is, specifically, to open the load switchgear 12 in the operation panel 4 to check whether the thermal fuse 14 on the internal circuit board is blown or not, and thus involves such a complicated disassembly work. Inspection requires a lot of work. On the other hand, according to the configuration in which the failure of the load switching device 12 can be individually displayed for each floor heating facility by the display operation of the display circuit 19 as described above, the load switching device 12 requiring a recovery measure can be easily specified. Therefore, the recovery measure can be easily performed without the need for disassembling the load opening device 12 in the recovery measure.

The present invention is not limited to the first embodiment. For example, the contact opening / closing state detection circuit 16 of the welding detection means 20 detects a temperature that exceeds a normal control upper limit temperature specified for the heated part by a predetermined temperature, based on the temperature detected by the temperature detector 3. It may be formed by an overheating detection circuit, and when the overheating temperature is detected, an output signal relating to the contact closed state is supplied to the welding detection circuit 17.

[0036]

The present invention is embodied in the form described above and has the following effects. According to the first aspect of the present invention, when the contact of the load switch is welded, it is detected, the temperature fuse connected in series to the contact is blown, and the electric heater embedded in the heated portion. Since the power supply to the load switch can be forcibly released, there is an effect that the electric heater of the embedded electric heating equipment can be prevented from generating heat when the contacts of the load switch are welded as described above. Degradation of insulation performance and wasteful power consumption can be eliminated.

According to the second aspect of the present invention, in addition to the effects of the first aspect, the fact that the contacts of the load switch are welded can be displayed by the display element of the display means. This has the effect that the display can be held until the power is turned off after the start of the display operation and the failure of the load switch due to the welding can be easily notified,
Accordingly, it is effective to adopt quick failure measures for the load switches of one or more load switching devices.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view schematically showing the configuration of a concrete embedded electric floor heating system including a load switching device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of the load switching device according to the first embodiment.

[Explanation of symbols]

A, B: electric floor heating equipment (embedded electric heating equipment), 1: concrete floor (heated part), 2: electric heater, 3: temperature detector, 4: operation panel, 11: temperature control device, 12: load switchgear, 13: load switchgear, 13a, 13b: contact, 14: thermal fuse, 15: indirect heat heater, 16: contact open / closed state detection circuit (weld detection means), 17: weld detection circuit (weld detection 18) fuse blowing circuit (fuse blowing means) 18a switching element 19 display circuit (display means) 19a display element 20 welding detection means

Claims (2)

[Claims] 1. A temperature control device comprising a load switch interposed between an electric heater and a power supply embedded in a heated portion together with a temperature detector, and operating according to a temperature detected by the temperature detector. A load switch for an embedded electric heating facility that opens and closes the load switch based on a control signal supplied from the device and performs energization and cutoff of power to the electric heater, wherein the load switch and A temperature fuse serially connected to a contact provided in the switch, a fusing indirect heater arranged near the fuse, welding detection means for detecting the welding of the contact of the load switch, A fuse blowing means connected to an output end of the welding detection means and allowing current to the indirectly heated heater in accordance with a fusing detection signal output from the welding detection means when the welding is detected; Load switchgear for thermal equipment. 2. A display means is connected to an output terminal of the welding detecting means, and when the welding is detected, a power supply is turned off after a display operation is started in response to a fusing detection signal output from the welding detecting means. 2. The load switching device for an embedded electric heating equipment according to claim 1, wherein the display means has a display element that maintains a display state until the display means.