JPH0140251Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to a power switchgear, and is particularly aimed at preventing dew condensation and low temperatures inside an operation box.

(Prior art and problems) The switchgear is made up of a main box that houses the shield disconnector, for example, and an operation box that houses the mechanism that operates the shield disconnector, which are stacked on top of each other, and are installed outdoors. may be done. For this reason, the switchgear is in an environment that is easily affected by outdoor temperature changes, and since the inside of the box is infiltrated with air unless it is filled with insulating gas (SF ₆ gas), there is no connection with the outside air. Condensation tends to occur due to temperature differences. If such condensation drips onto the operating mechanism, it will cause rust on the mechanical components. If the operating mechanism becomes rusty, the speed and smoothness of mechanical operation will be impaired, and there is a risk that the appropriate opening and closing operations of the breaker will be inhibited. Furthermore, if the internal temperature suddenly decreases due to a decrease in the outside temperature, the rubber seals, grease, oils and fats, sensors, etc. are likely to deteriorate at low temperatures, which is also dangerous. Furthermore, the operating mechanism section includes not only mechanical parts but also electrical parts such as auxiliary switches, control relays, microswitches, and terminal blocks, and there is a risk that the insulation performance of these parts may deteriorate.

Therefore, conventional dew condensation prevention means use only a temperature detector or a humidity detector to operate the heater, and in the case of only the former, the heater always operates within a predetermined setting range. This resulted in wasted power consumption. Further, in the case of only the latter, there was a problem that the heater could not be operated at low temperatures such as sub-zero temperatures. There is also a device that operates a heater when the relative humidity outside the panel is above a predetermined value and the temperature difference inside and outside the panel is below a predetermined value, but this is a means of measuring the temperature and humidity outside the panel. , and a means to measure the temperature inside the panel is required, which also requires a relay in the heater control circuit, complicating the circuit configuration and requiring a ventilation fan, resulting in high costs and running costs. There is.

(Purpose of the invention) In view of such conventional technology, the present invention aims to prevent dew condensation inside the operation box and protect the equipment and electrical components inside the operation box from rusting. .

(Structure of the invention) Based on the above-mentioned purpose, the present invention provides a switchgear as described above, in which the inner surface of the operation box is coated with a fine porous dew-absorbing film, and a heater is installed in the inner bottom of the control box. By installing a temperature detector and a humidity detector fixedly in each, and connecting the heater, temperature detector, and humidity detector so that they can operate in a parallel circuit, it is possible to set either the set temperature or the humidity. When detected, the heater is heated with electricity,
This prevents dew condensation by increasing the temperature inside the operation box and lowering the relative humidity inside the operation box.

(Example) An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway front view of a switching device showing a schematic configuration, and FIG. 2 is a configuration diagram of a heater drive circuit.

Reference numeral 1 denotes an operation box, and the operation box 1 is a hollow box housing an operation device 2, and is fixedly installed on the ground E. Reference numeral 3 denotes a condensation absorbing film. The condensation absorbing film 3 is made of a hygroscopic paint (water-based synthetic resin paint, such as Taiyo Tetsu MS#5000 manufactured by Taiyo Paint Co., Ltd.) coated on the inner surface of the operation box 1, and has heat insulating properties. It is a synthetic resin paint that has fine porosity and has the ability to absorb moisture into its pores, and also has the ability to release absorbed moisture when the atmosphere becomes dry, and can repeat this process repeatedly. be. 4 is a humidity detector, 5 is a temperature detector (thermostat), and both detectors 4, 5
are each fixed to the inner wall of the operation box 1 and are in contact with the dew condensation absorbing film 3. Reference numeral 6 denotes a heater, and the heater 6 is fixed to the inner bottom of the operation box 1.
This heater 6 is driven by a drive circuit shown in FIG.
The humidity detector 4 and the temperature detector 5 are respectively connected in parallel.

In addition, in Figure 2, 7 is a heater disconnector, 8
9 is a disconnection detector, 9 is an overcurrent detector, and 10 is a voltage detector. Further, in FIG. 1, reference numeral 11 denotes a main body box, and the main body box 11 is fixed to the upper part of the operation box 1, and houses the following main equipment inside. The main equipment includes a lightning arrester 12, a three-phase shield breaker 13, power supply side and load side disconnectors 14, an earthing switch 15, a current transformer 17, and the like. 18 is a power bus, and 19 is a load bus.

Next, the operation of the present invention will be explained based on the above embodiment. In FIG. 1, when the temperature of the operation box 1 itself decreases due to a sudden drop in outside temperature or a drop in the outside temperature at night, the air inside the operation box 1 cools rapidly and the moisture contained therein is generated on the inner wall. This moisture is absorbed into the fine pores of the dew condensation absorbing membrane 3. Therefore, in such a state, by setting the humidity detector 4 to operate, the heater 6 is heated by electricity, and the air inside the operation box 1 is warmed by the heat generated by the heater 6, thereby preventing dew condensation.

In addition, by setting the detection temperature set value of the temperature detector 5 so that it operates at a constant temperature outside the range in which the humidity detector 4 operates, for example, when the temperature inside the operation box 1 drops significantly, the temperature detector 5 Therefore, the heater 6 is activated and the temperature inside the operation box 1 is raised regardless of the occurrence of dew condensation, so that it is possible to protect the low-temperature avoidance part. In short,
It is possible to adjust the internal environment of the operation box 1 to be optimal for the environment in which the opening/closing device is installed.

Then, when the temperature inside the operation box 1 rises, the moisture absorbed by the condensation absorbing film 3 is released into the air inside the operation box 1 again, radiates outside the operation box 1 through appropriate gaps, etc., and condenses. The absorbent membrane 3 dries and returns to its original state. Furthermore, since the dew condensation absorbing film 3 also has heat insulating properties, it has the effect of keeping the inside of the operation box 1 warm and delaying dew condensation.

(Effects) According to the present invention described above, the condensation absorbing film 3 is coated on the inner surface of the operation box 1 to provide hygroscopic and heat insulating properties to prevent and delay condensation, and the humidity detector 4 and temperature Since the heater 6 connected in parallel with the detector 9 is provided inside the operation box 1, when condensation occurs, the condensation absorbing film absorbs it, prevents the internal air from becoming moist, and prevents the operation mechanism from rusting. When the temperature drops significantly, the heater 6 raises the temperature inside the operation box 1 to protect the low-temperature-shielding parts. Furthermore, since the condensation absorbing film is used, the configuration of the heater control circuit is simplified, and costs and running costs are reduced. Therefore, the internal environment of the operation box 1 due to dew condensation and low temperatures is automatically adjusted, and the effect is that smooth operation of the opening/closing device can be easily ensured.

[Brief explanation of the drawing]

FIG. 1 is a partially vertical front view showing an embodiment of the present invention, and FIG. 2 is a diagram showing the configuration of a heater drive circuit. 1... Operation box, 3... Condensation absorption membrane, 4... Humidity detector, 5... Temperature detector, 6... Heater.

Claims (1)

[Scope of utility model registration request] In a switchgear equipped with an operation box that hermetically stores the operation mechanism of a break switch, the inner surface of the operation box 1 is coated with a fine porous condensation absorbing film 3, and the operation box 1 is A humidity detector 4 and a temperature detector 5 are provided inside, and a heater 6 is fixedly provided at the inner bottom, and the heater 6, the humidity detector 4, and the temperature detector 5 can be electrically heated in a parallel circuit. A switchgear characterized by being connected to.