Which action ensures the disconnect cannot be re-energized after service work?

Which action ensures the disconnect cannot be re-energized after service work?

• A. Test the power circuit on the load side of the disconnect
• B. Test the power circuit on the line side of the disconnect
• C. Test the control circuit
• D. Lock and tag the disconnect

Answer: (D)

Lockout/tagout is the key safety practice here. Locking and tagging the disconnect creates a physical barrier that only the person who applied the lock can remove. The padlock and the warning tag communicate that the equipment is not to be energized until the lock is removed, ensuring no one else can re-energize it while work is being done. This is why it’s the only action that truly prevents re-energization after service. Testing the circuit on the load side or line side only checks whether voltage is present; it does not stop someone from closing the switch or energizing the circuit again. Testing the control circuit verifies the control signals, but it also does not provide a persistent prohibition against re-energizing. Locking and tagging, by contrast, provides a verifiable, authorized barrier to energization until the lock is removed by the person who applied it. After work is complete and conditions are safe, the lock and tag are removed only by that person, and the system can be safely re-energized.

Lockout/tagout is the key safety practice here. Locking and tagging the disconnect creates a physical barrier that only the person who applied the lock can remove. The padlock and the warning tag communicate that the equipment is not to be energized until the lock is removed, ensuring no one else can re-energize it while work is being done. This is why it’s the only action that truly prevents re-energization after service.

Testing the circuit on the load side or line side only checks whether voltage is present; it does not stop someone from closing the switch or energizing the circuit again. Testing the control circuit verifies the control signals, but it also does not provide a persistent prohibition against re-energizing. Locking and tagging, by contrast, provides a verifiable, authorized barrier to energization until the lock is removed by the person who applied it. After work is complete and conditions are safe, the lock and tag are removed only by that person, and the system can be safely re-energized.