How is energy source identification performed before work?

• A. By locating and labeling all sources (panels, breakers, switches, disconnects) and verifying their status before work
• B. Identify only the main disconnect
• C. Not necessary to identify energy sources
• D. Record energy sources after completing work

Answer: (A)

Understanding how to identify energy sources before starting work is about knowing every path that could energize the equipment. This means you must locate and label all potential sources—panels, breakers, switches, and disconnects—and verify their status before you begin. By mapping out all possible feeds, you ensure nothing can re-energize the circuit while you’re working, which is essential for safe lockout/tagout and for confirming zero energy with proper testing. This comprehensive identification prevents surprises from downstream or remote sources that a single main disconnect might not control. If you wait to identify sources after starting, or you only check the main disconnect, you risk exposure to unexpected energy and an arc flash. Not identifying sources at all is unsafe, because it leaves workers vulnerable to energization. So the best practice is to locate, label, and verify every energy source before any work starts.