Before servicing equipment that may be energized from normal and standby sources, what must the worker do?
- AOpen only the normal-source breaker
- BRely on an indicator lamp
- CBegin work after pressing the stop button
- Isolate and verify every source
Why D is correct
Multiple sources can backfeed equipment. An electrically safe work condition requires source identification, isolation, lockout/tagout, and properly performed absence-of-voltage verification; controls and lamps are not isolating means.