What should be verified before commencing work on a de-energized circuit?

Before beginning work on a de-energized circuit, it is crucial to verify that the circuit is truly off with a tester. This step ensures safety by confirming that no voltage is present and that the circuit is genuinely de-energized. Simply relying on labels or operational assumptions can lead to dangerous situations, such as accidental contact with a live circuit. A reliable voltage tester provides definitive proof that the circuit is safe to work on, thereby protecting the electrician from electrical shock and potential injuries.

The other aspects, while important in the overall safety protocol, do not directly confirm the state of the specific circuit being worked on. Ensuring the presence of voltage would indicate the opposite of what is desired in this context, while the status of adjacent circuits and personal protective equipment, although critical for safety, do not verify whether the specific circuit in question is de-energized.