For electrical equipment, especially high-voltage electrical equipment, insulation performance tests shall be carried out after a period of time or operation. Detect its electrical insulation properties. In accordance with the provisions of the International "Procedures for Preventive Testing of Electrical Equipment":

1. The phase-separated insulation resistance of the fully connected phase-closed busbar with a rated voltage of 15kV and above is not less than 50MQ at room temperature. The 6kV common box type enclosed busbar has a phase separation insulation resistance value of not less than 6MQ at room temperature.

2. The insulation resistance of the general busbar should not be lower than 1MQ/kV. The insulation resistance of an electrical device refers to the ratio of the DC voltage U applied to its electrical insulation material and the total electrical conduction current through it ie R=U/I. By measuring the insulation resistance of electrical equipment, the insulation state of the equipment can be checked. Such as: whether it is damp, aging, etc. Due to the influence of some unfavorable factors, the data measured by the test is not accurate, and the actual state of the equipment insulation cannot be truly reflected, which affects the correct judgment of the staff on the condition of the equipment. To this end, the author will communicate with you the problems and improvement measures encountered in the actual work process.

3.The effect of temperature on insulation (measuring insulation resistance can be used with HT2500 series high-voltage insulation resistance tester with temperature compensation function) When the insulation is in a humid environment, the surface will absorb moisture to form a water film, causing its surface to conduct electricity. Increase, so that the insulation resistance drops significantly. In addition, some insulating materials have a capillary action, which absorbs more moisture and increases the conductance, resulting in a decrease in overall insulation. In this case, equipotential shielding should be added.