JPH08251728A - Dew condensation preventing device for switchgear - Google Patents

Abstract

PURPOSE: To reduce the size of a switchgear and to omit a special bracket by attaching a thermal shielding plate to the bottom surface of container inside the switchgear, providing a temperature sensor for the inner surface of an outer plate and an inner temperature sensor, and controlling the relative humid ity in the switchgear by the operation of a heater. CONSTITUTION: A thermal shielding plate 13 is attached to the inner surface of an outer plate 1 of a switchgear 2. Furthermore, a temperature sensor 14 for the inner surface of the outer plate for detecting the temperature of the inner surface of the outer plate 1 is embedded in the thermal shielding plate 13, and an inner temperature sensor 15, which detects the temperature inside the switchgear 2, is provided in a container 3. When the internal temperature is larger than the temperature in the outer plate, a comparator circuit 16 outputs the comparison signal. When the relative humidity is over a preset value, a heater is operated by a control circuit 18, and dew condensation is prevented. As a result, the size of the switch gear 2 decreases, and a special attaching hardware for the container 3 is not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switchgear condensation prevention device for preventing condensation inside a switchgear installed outdoors by automatic operation of a heater.

[0002]

2. Description of the Related Art A conventional dew condensation preventing device for a switch gear will be described with reference to FIGS. In these figures, 1 is an outer plate of the switchgear 2, 3 is a container in which a bottom plate is attached to the inner surface of the outer plate 1 by a bolt or the like, and 4 is a power supply and signal take-out projecting above the container 3. A terminal block 5 is an insulation resistance sensor provided inside the container 3, and detects an insulation resistance (not shown) in the container 3 and outputs a resistance value. Reference numeral 6 denotes a determination circuit to which the resistance value is input and which outputs a resistance signal when the resistance value is equal to or less than a set value.

Reference numeral 7 denotes a humidity sensor provided in the container 3, which constantly detects the relative humidity inside the switchgear 2 and outputs a relative humidity value, which is a resistance sensor when the temperature is low, the humidity is high, or the weather changes suddenly. 5 response speed is covered. Reference numeral 8 denotes a determination circuit which inputs the relative humidity value and outputs a humidity signal when the relative humidity value is equal to or more than a set value.

Reference numeral 9 is an OR circuit to which the outputs of the judgment circuits 6 and 8 are input. The control circuit 10 is composed of the judgment circuits 6 and 8 and the OR circuit 9, and the resistance signal from the judgment circuit 6 or the judgment circuit 8 is used. When the humidity signal is input, the OR circuit 9, that is, the control circuit 10 outputs an operation signal for operating the heater 11.

That is, when the resistance value detected by the insulation resistance sensor 5 is less than the set value or the relative humidity value detected by the humidity sensor 7 is more than the set value, the heater 11 is operated and the heater 11 is operated. As a result, the temperature inside the switchgear 2 rises, the relative humidity drops, and the occurrence of dew condensation is prevented.

The setting value of the judgment circuit 6 to which the resistance value is input is, for example, when the temperature is 40 ° C. and the relative humidity is 85% phase, while the setting value of the judgment circuit 8 to which the relative humidity value is input. The value is for example 65% or 85%.

However, as shown in FIG. 3, when the container 3 is directly attached to the outer plate 1, the outer surface of the outer plate 1 receives solar radiation to absorb heat, and the temperature of the outer plate 1 rises. Heat is transferred between the container 1 and the container 3, the temperature of the container 3 rises, and the container 3
Both sensors 5 and 7 inside are adversely affected, and both sensors 5 and 7 do not operate normally.

Therefore, as shown in FIG. 5, the container 3 is attached to the outer plate 1 to 50 to 1 by using the mounting hardware 12 made of a collar.
It is attached by being floated by about 00 mm to prevent heat transfer between the outer plate 1 and the container 3.

[0009]

In the conventional dew condensation preventing device for the switchgear shown in FIG. 5, the container 3 is installed in order to prevent heat transfer between the outer plate 1 and the container 3. Skin 1
Since it floats from the inner surface of the switchgear, it is necessary to avoid the interference between the device housed in the switchgear 2 and the container 3, and the size of the switchgear 2 becomes large, and a collar or the like is attached. The metal fitting 12 and long bolts are required. Further, various kinds of mounting hardware 12 are required depending on the mounting location of the container 3, standard members cannot be used, and it is necessary to design and manufacture the mounting hardware 12 individually. However, there is a problem in that it becomes expensive, and that the container 3 cannot be attached to the outer plate 1 due to loss or damage of the attachment hardware 12.

Further, when the internal temperature of the switchgear 2 is equal to or lower than the internal surface temperature of the outer plate 1, dew condensation does not occur on the inner surface of the outer plate 1 and the operation of the heater 11 is unnecessary. In the conventional dew condensation prevention device, the heater 11
However, there is a problem in that the internal temperature of the switchgear 2 rises, the equipment housed inside the switchgear 2 has a short life, and is disadvantageous in terms of energy saving. is there.

In consideration of the above points, the present invention does not increase the size of the switch gear and does not require any special mounting hardware.
An object of the present invention is to provide a dew condensation preventing device for a switchgear, which is inexpensive, does not shorten the life of internal equipment, and realizes energy saving.

[0012]

In order to solve the above problems, a dew condensation preventing device for a switchgear according to the present invention is provided with a container provided inside the switchgear and an outer part of the switchgear fixed to a container. A heat shield plate attached to the inner surface of the plate, an outer plate inner surface temperature sensor embedded in the heat shield plate to detect the inner surface temperature of the outer plate and output the inner surface temperature of the outer plate, and a switch provided in the container. An internal temperature sensor that detects the internal temperature of the gear and outputs the internal temperature, a comparison circuit that is provided in the container and that outputs a comparison signal when the internal temperature is higher than the internal temperature of the outer plate, and an internal temperature sensor An insulation resistance sensor provided to detect the insulation resistance in the container and output a resistance value,
A humidity sensor installed in the container that detects the relative humidity inside the switchgear and outputs the relative humidity value, and the comparison signal is input, and the input resistance value is less than or equal to the set value or the relative humidity value is greater than or equal to the set value. In this case, a control circuit for outputting a driving signal for driving the heater in the switch gear is provided.

[0013]

In the switchgear dew condensation prevention device of the present invention having the above-described structure, the heat shield plate fixed to the bottom surface of the container inside the switchgear is attached to the inner surface of the outer plate of the switchgear. Therefore, the size of the switch gear is small, no special mounting hardware is required, and the cost is low.

Further, an outer plate inner surface temperature sensor for detecting the temperature of the inner surface of the outer plate and outputting the inner surface temperature of the outer plate is embedded in the heat shield plate, and the temperature inside the switch gear is detected inside the container to detect the inner temperature. An internal temperature sensor that outputs the temperature is provided.When the internal temperature is higher than the internal temperature of the outer plate, the comparison circuit outputs a comparison signal, and the insulation resistance sensor inside the container detects the insulation resistance inside the container and detects the resistance. Outputs the value, the humidity sensor in the container detects the relative humidity in the switch gear and outputs the relative humidity value, the comparison signal is input to the control circuit, and the input resistance value is less than the set value or the relative humidity value. When is higher than the set value, the control circuit outputs an operation signal to operate the heater in the switchgear, so the temperature inside the switchgear does not rise due to unnecessary operation of the heater and the life of the internal equipment is shortened. Or never , Energy saving can be realized.

[0015]

EXAMPLE One example will be described with reference to FIGS. In these drawings, the same reference numerals as those in FIGS. 3 and 4 indicate the same or equivalent parts, and the different points are as follows.

Reference numeral 13 denotes a heat shield plate fixed to the bottom surface of the container 3 and attached to the inner surface of the outer plate 1 of the switchgear 2 for transferring heat between the outer plate 1 and the container 3. To prevent. Reference numeral 14 denotes an outer plate inner surface temperature sensor embedded in the heat shield plate 13, which is in direct contact with the inner surface of the outer plate 1, accurately detects the temperature of the inner surface of the outer plate 1, and outputs the outer plate inner surface temperature. .

Reference numeral 15 denotes an internal temperature sensor provided above the inside of the container 3 to detect the internal temperature of the switch gear 2 and output the internal temperature. 16 is both sensors 14, 15
Is a comparison circuit to which the internal temperature and the outer plate inner surface temperature output by are input, and outputs a comparison signal when the inner temperature is higher than the outer plate inner surface temperature.

Reference numeral 17 denotes an AND circuit to which the output of the comparison circuit 16 and the output of the OR circuit 9 are input.
8. Control circuit 18 by OR circuit 9 and AND circuit 17
The resistance signal from the determination circuit 6 or the humidity signal from the determination circuit 8 is input to the OR circuit 9, and the OR circuit 9
When the signal from the AND circuit and the comparison signal from the comparison circuit 16 are input to the AND circuit 17, the AND circuit 17, that is, the control circuit 18 outputs an operation signal for operating the heater 11.

[0019]

Since the present invention is configured as described above, it has the following effects.

In the device for preventing dew condensation of the switch gear 2 of the present invention, the heat shield plate 13 fixed to the bottom surface of the container 3 inside the switch gear 2 is attached to the inner surface of the outer plate 1 of the switch gear 2. The size of the switchgear 2 becomes smaller,
It is possible to reduce the cost because there is no need for a special fitting for the container 3 and there is no need to individually design and manufacture the fitting.

Furthermore, an outer plate inner surface temperature sensor 14 for detecting the inner surface temperature of the outer plate 1 and outputting the inner surface temperature of the outer plate 1 is embedded in the heat shield plate 13, and the temperature inside the switchgear 2 is stored in the container 3. An internal temperature sensor 15 for detecting the internal temperature and outputting an internal temperature. When the internal temperature is higher than the internal temperature of the outer plate, the comparison circuit 16 outputs a comparison signal and the insulation resistance sensor 5 in the container 3 causes 3 detects the insulation resistance in 3 and outputs the resistance value, and the humidity sensor 7 in the container 3 detects the relative humidity in the switch gear 2 and outputs the relative humidity value.
When the comparison signal is input to the controller, and the input resistance value is less than or equal to the set value or the relative humidity value is greater than or equal to the set value, the control circuit 18 outputs an operation signal for operating the heater 11. There is no temperature rise inside the switchgear 2 due to, and the life of the internal equipment is not shortened,
In addition, energy saving can be realized.

[Brief description of drawings]

FIG. 1 is a cutaway side view of one embodiment of the present invention.

FIG. 2 is a block diagram of FIG.

FIG. 3 is a cut side view of a conventional example.

FIG. 4 is a block diagram of FIG.

FIG. 5 is a cut side view of another conventional example.

[Explanation of symbols]

 1 Outer Plate 2 Switch Gear 3 Container 5 Insulation Resistance Sensor 7 Humidity Sensor 11 Heater 13 Heat Shield Plate 14 Outer Plate Inner Surface Temperature Sensor 15 Internal Temperature Sensor 16 Comparison Circuit 18 Control Circuit

Claims (1)

[Claims] 1. A container provided inside a switchgear, a heat shield plate fixed to a bottom surface of the container and attached to an inner surface of an outer plate of the switchgear, and embedded in the heat shield plate. An outer plate inner surface temperature sensor that detects the inner surface temperature of the outer plate and outputs the inner surface temperature of the outer plate; and an inner temperature sensor that is provided in the container and that detects the inner temperature of the switchgear and outputs the inner temperature. And a comparison circuit which is provided in the container and outputs a comparison signal when the internal temperature is higher than the inner surface temperature of the outer plate, and which is provided in the container and detects an insulation resistance in the container. An insulation resistance sensor that outputs a resistance value, a humidity sensor that is provided in the container and that detects a relative humidity inside the switchgear and outputs a relative humidity value, and the comparison signal is input and the input The resistance is less than the set value Or when the relative humidity value is equal to or greater than the set value, anti-condensation device for switchgear and a control circuit for outputting a driving signal for driving the heater in the switchgear.