What step is essential to confirm a circuit is de-energized before work begins?

• A. Rely on the appearance of equipment to judge energy status.
• B. Verify de-energization with a test.
• C. Turn off the main switch and assume it stays off.
• D. Ask a coworker if they think it’s off.

Answer: (B)

Verifying zero voltage with a properly rated test instrument is the essential step. You can’t rely on how equipment looks or assume that flipping a switch will make everything safe. Voltage can remain present in stored energy, capacitors, or through backfeeds and other sources, so appearance is not a reliable indicator of a de-energized state. Turning off the main disconnect and hoping it stays off doesn’t guarantee that all parts of the circuit are truly dead, and asking a coworker provides no direct confirmation of the electrical status. By using the right test equipment to check for the absence of voltage at the work area (and following lockout/tagout procedures), you establish, with objective evidence, that it is safe to begin work.