Most preparations for measurement are related to work safety. All operations must be performed carefully to avoid accidents. Special attention should be paid to remind people who have not participated in the measurement, but they may be close to the work place due to some reasons.

A digital megohmmeter should be used to measure the insulation resistance. The conductor should be disconnected from the power supply. In order to avoid affecting the measurement results of the electric field, the surrounding equipment must also be powered off.

Although the test voltage is very high when measuring the insulation resistance of the wiring, the measurement itself is thin and almost undisturbed, due to the fact that due to the extremely high resistivity of the insulator, even at high voltages, the microampere current is Will penetrate the insulator, and the measurement of these currents finally gives a resistance value in the order of megohm units.

The cable under test is part of the working line of the equipment, and it must be completely disconnected from the rest of the lines before the measurement.

Preparation plan for measuring insulation resistance:

The configuration and length of the cables to be tested must be considered because they will all be under high test voltages, and the impact of this pressure on people throughout the existence process must be eliminated. This can be achieved by posting warning signs and monitoring the test area.

After disconnection, a long cable that is usually exposed to high voltage may carry a large amount of residual charge or pickup charge from surrounding high-voltage equipment, which is dangerous to people and damages the equipment during discharge, which may affect Megohmmeter measurement results. For all these reasons, the cable under test and all conductive electrical components must be discharged through grounding.