When measuring insulation resistance using a water-cooled generator insulation resistance tester, the following points should be noted:

 

    1. Before measuring the insulation resistance of equipment, the power supply must be disconnected first; for equipment with capacitive properties (such as cable lines), discharge must be performed first, and testing can only be carried out after confirming there is no electricity.

 

    2. The leads of the insulation resistance meter should be made of multi-strand soft copper wire with good insulation performance, and the two wires should not be twisted together to avoid measurement errors.

 

    3. The water-cooled generator insulation resistance tester should be placed in a horizontal position. Before connecting the wires, first rotate the insulation meter to see if the pointer is at the “∞” position. Then short-circuit the (L) and (E) terminals, slowly rotate the insulation resistance tester, and check if the pointer points to the “zero” position.

 

    4. When measuring motors, large-capacity transformers, cables, and capacitors, a certain charging time is required. The larger the capacitance, the longer the charging time. Generally, the reading after rotating the insulation resistance meter for one minute is taken as the standard.

 

    5. The surface of the object being measured must be wiped clean and free of dirt to prevent leakage and ensure measurement accuracy.

 

    6. To ensure the reliability of the measurement results, repeat the measurement more than twice.