What Are The Metal Parts Of Electrical Equipment That Do Not Need To Be Grounded Or Connected To Zero

1. Insulator in dry rooms with poorly conductive floors such as wood and asphalt, the casing of power equipment with an AC rated voltage of 380V or less and a DC rated voltage of 440V or less, except when maintenance personnel may touch the casing of the power equipment and grounded objects at the same time;

2. In dry places, the casing of power equipment with an AC rated voltage of 127V or less and a DC rated voltage of 110V or less, except in explosion-hazardous places;

3. The casing of electrical measuring instruments, relays and other low-voltage electrical appliances installed on distribution panels, control panels and distribution devices, as well as the metal base of insulators that will not cause dangerous voltage on the support when insulation damage occurs;

4. Equipment installed on grounded metal structures (good electrical contact should be ensured), such as bushings, etc., except in explosion-hazardous places;

5. Brackets in battery rooms with a rated voltage of 220V or less;

6. The casing of motors and electrical appliances that have reliable electrical contact with the grounded machine tool base, except in explosion-hazardous places;

7. Railway tracks extending from power plants, substations and industrial enterprises.