1. Insulation resistance meter selection

It is necessary to correctly select an insulation resistance meter with a suitable rated voltage. The rated voltage of the insulation resistance meter is selected according to the rated voltage of the device under test. The rated voltage of the insulation resistance meter, that is, the DC voltage of its internal power supply is too high, which may damage the insulation of the device under test during testing; the rated voltage of the insulation resistance meter If it is too low, the measured result cannot reflect the insulation resistance of the electrical equipment under the working voltage. General regulations stipulate that when measuring equipment with a rated voltage below 500V, an insulation resistance meter of 500~1000V should be used; when the rated voltage is above 500V, an insulation resistance meter of 1000~2500V should be used.

2. How to use the insulation resistance meter

①Check whether the position of the pointer "0" and "∞" are correct before use. The inspection method is to open the terminals “L” and “E” first, place the insulation resistance meter in an appropriate horizontal position, and shake the handle to the rated speed of the generator (usually 120r/min), the pointer should point to “∞ "Position. If it cannot reach "∞", it means that the lead wire for testing is poorly insulated or the insulation resistance meter itself is damp. Use a dry and clean soft cloth to wipe the insulation between the "L" terminal and the "E" terminal. If necessary, place the insulation resistance meter on the insulating pad. If it does not reach the "∞" value, replace the test lead. Then short-circuit the "L" and "E" terminals, shake the generator slightly, and the pointer should point to the "0" position. If the pointer does not point to zero, it indicates that the test lead is not connected well or there is a problem with the insulation resistance.