What is the procedure for temporary power isolation during maintenance?

• A. Lockout/Tagout and verify isolation.
• B. Verify isolation and test equipment only.
• C. Complete permit-to-work only.
• D. Lockout/Tagout, verify isolation, test equipment, complete permit-to-work, communicate with workers, and remove tags only after work is complete.

Answer: (D)

Temporary power isolation during maintenance requires a comprehensive safe-work sequence that prevents any unexpected energization while work is underway. Start with Lockout/Tagout to physically prevent energy from being supplied to the equipment. Then verify isolation to confirm all energy sources are actually isolated and cannot re-energize the circuits. Testing the equipment is essential to ensure there is no stored or residual energy that could cause a release when work begins. A permit-to-work must be completed to formally authorize the task, define the scope, hazards, controls, and responsibilities. Communicating with all workers ensures everyone knows the isolation status and who is working, so no one inadvertently re-energizes or interferes with the work. Tags should be removed only after the work is finished and the area is declared safe, ensuring energy cannot be re-energized prematurely.