Pay attention to details when using the insulation resistance tester

　　Commonly referred to as megohmmeters or megohmmeters, they are widely used to measure the insulation resistance of generators, motors, power transformers , wiring, electrical boxes and other electrical devices (such as cables for control, signal, communication and power). They are often used in routine maintenance procedures to indicate changes in the insulation resistance of motors over months or years. Large changes in insulation resistance may indicate potential failures. Therefore, an insulation resistance tester is needed to jack up calibration to ensure that the instrument itself has not changed over time.

　　When using an insulation resistance meter to measure insulation resistance, the following points should be noted:

　　1. When measuring the insulation resistance of the equipment , the power supply must be disconnected first; for equipment with capacitive properties (such as cable lines), it must be discharged first and tested only after confirming that there is no electricity.

　　2. The leads of the insulation resistance meter should be made of multiple strands of soft copper wire with good insulation performance. The two wires cannot be twisted together to avoid measurement errors.

　　3. The insulation resistance meter should be placed in a horizontal position. Before connecting the wires, turn the insulation energy meter to see if the pointer is at "∞". Then short-circuit the two terminals (L) and (E), and slowly turn the insulation resistance meter to see if the pointer is at 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 the insulation resistance meter rotates for one minute is used as the standard.

　　5. When testing insulation by shaking, the insulation resistance meter should maintain a certain number of revolutions, generally 120r/min.

　　6. The surface of the object to be measured must be wiped clean and free of dirt to avoid leakage and affect the accuracy of the measurement.

　　7. To ensure the reliability of the measurement results, the shaking test must be repeated more than twice.