The insulation resistance tester is a kind of transformer dc resistance tester which is small in size, light in weight and easy to carry. The function of self-test and automatic calibration reduces the difficulty of using and maintaining the instrument, and is also an ideal equipment for measuring the dc resistance of transformer windings and high-power inductive devices.

In practice, if the insulation resistance tester overheats, it is mainly caused by the following points. Let's see.

1. If the wires and equipment are unreasonable or the current carrier exceeds the rated value, the overload fever of the equipment will be caused by the overload design.

2, all kinds of electrical equipment with poor heat dissipation generally have certain heat dissipation or ventilation measures. If these measures are damaged, the equipment may overheat.

3, bad contact wire connector connection is bad, bad contact, copper and aluminum joint electrolytic corrosion will lead to overheating.

4, the core heating transformer and motor insulation damage or long-term overvoltage, eddy current loss and hysteresis loss increase, will cause the transformer and motor core heating, easy to overheat.

5. If improperly installed or used, electric lamps and furnaces that directly use the heat generated by the current may overheat. If the electrical equipment overheats due to the above or other reasons, the conductor temperature will rise and the surrounding combustible or object will be heated, possibly causing a fire.

6, short circuit, the current in the line will increase several times to dozens of times, thus producing a large amount of heat, so that the insulation layer of the conductor immediately burned off; If the heat flows into the surrounding combustible material, it will cause combustion. Short circuits are caused by equipment insulation aging or loss due to high temperature, humidity, and corrosion, or mechanical damage to insulation during the installation of electrical equipment. In addition, lightning overvoltage breakdown insulation, wiring errors, shell impact may also lead to short circuit fault.