2. The insulation resistance index of electrical equipment and electrical circuit. Insulation resistance refers to the resistance between the two separated conductors by insulating material. In order to ensure the safety of the electric equipment operation, it should propose a minimum requirement for the polarity between the conductive body or the insulation resistance between the conductive body and the shell.
By measuring insulation resistance of electrical equipment, it can achieve the purchase as follows:
a. Learn the insulation performance of the insulation structure. Reasonable insulation structure (or insulation system) composed of high quality insulation material should have good insulation performance and high insulation resistance.
b. Learn the insulation processing quality of the electrical products. The insulation treatment of electrical equipment is poor; its insulation performance will be obviously decreased.
c. Learn the insulation damp and polluted situation, when the insulation of the electrical equipment is damp and polluted the insulation resistance is usually decreased obviously.
d. Inspect whether the insulation can withstand the withstand voltage test. When do the withstand voltage test, if the insulation resistance of electrical equipment is lower than a certain value, it will produce large test current, which leads to thermal breakdown and damage the insulation of electrical equipment. Therefore, it is usually to measure the insulation resistance before the withstand voltage test in all kinds of test standards.