The scale of the insulation resistance tester is in megaohm (M Ω). It is a measuring instrument commonly used by electricians and is mainly used to check the insulation resistance of electrical equipment, household appliances or electrical lines to ground and between phases, so as to ensure that these equipment, appliances and lines work in a normal state and avoid electric shock casualties, equipment damage and other accidents.
1. It is forbidden to measure the insulation resistance during lightning or near the high-voltage equipment. It can only be measured when the equipment is not electrified or inductive.
2. During the telemetering, no one is allowed to work on the tested equipment.
3. The tramegger wires shall not be twisted together but separated.
4. Do not touch the megger with hands before it stops rotating or the tested equipment is not discharged. Do not touch the metal part of the lead when removing the wire.
5. At the end of the measurement, discharge the large capacitance equipment.
6. The measuring flexible wire led out of the megger terminal shall be well insulated, and proper distance shall be kept between two conductors and between the conductor and the ground to avoid affecting the measurement accuracy.
7. In order to prevent the surface leakage resistance of the equipment under test, when using a megger, the middle layer of the equipment under test (such as the inner insulation between the cable shell cores) should be connected to the protective ring.
8. Regularly verify its accuracy.