The intelligent insulation resistance tester can be widely used in the maintenance of electrical equipment such as substations and power plants. It is very suitable for testing various high-voltage equipment, including switchgear, transformers, reactors, capacitors, motors, generators and cables for insulation. Measurement of Resistance (IR), Absorption Ratio (DAR), Polarization Index (PI).
In actual use, if the insulation resistance tester overheats, it may be caused by the following points.
1. Iron core heating transformers and motors and other equipment insulation damage or long-term overvoltage, eddy current loss and hysteresis loss will cause the transformer and motor iron core to heat up and easily overheat.
2. Poor heat dissipation Various electrical equipment generally have certain heat dissipation or ventilation measures. If these measures are damaged, it may cause the equipment to overheat.
3. Poor contact The connection of the wire joint is not firm, the contact is poor, and the electrolytic corrosion of the copper and aluminum joints will lead to overheating.
4. Overload design When the selection of wires and equipment is unreasonable or the current load exceeds the rated value, the equipment will be overloaded and heated.
5. The heat generated by the direct use of electric lamps and electric furnaces may also overheat if installed or used improperly. If electrical equipment overheats conductors for the above reasons or other reasons and heats surrounding combustible materials or objects, a fire may result.
6. The short-circuit current in the line generally increases several times to dozens of times, and a large amount of heat is rapidly generated. The heat can immediately burn through the insulating layer of the conductor; if it heats the surrounding combustibles, it will cause combustion. Short circuits are caused by the loss of insulating capacity of the insulation of the equipment due to aging or high temperature, humidity or corrosion, or the mechanical damage to the insulation during the installation of the electrical equipment. In addition, lightning overvoltage breakdown insulation and wiring errors, shell collisions, etc. may cause short-circuit faults.