Lock It Out & Prove It Dead
DraftA telecom shelter with more than one way to bite: utility, a generator on an automatic transfer switch, a −48 V battery plant, a UPS. Find every source, lock it, prove it dead.
Lock It Out
Identify every energy source, shut down in the right order, lock and tag, then live-dead-live before you start work.
Dress for the Panel
Read the arc flash label and put together the PPE for an absence-of-voltage test.
Practice, not qualification. The shelter, the labels and their values are invented for the game. Work to your employer’s written procedures, the actual arc flash label, and the NFPA 70E edition your employer has adopted.