September 7, 2021
Electrical Enclosure with Incoming 3-Phase 480V AC Power
Worker approaches the enclosure and the disconnect switch for the 480V power source is in the OFF position. The disconnect switch has failed with one phase (L1) in the closed position (L2, L3 are open). The ground leads of the devices are NOT connected to ground because of an improper installation or termination failure.
The worker applies a lock. Following safety procedures, the worker performs an absence of voltage test with the electrical enclosure closed using a permanently mounted device.