Which sequence correctly summarizes lockout/tagout procedures before servicing electrical equipment?

• A. De-energize the equipment, verify zero energy, and tag out.
• B. Tag out, then energize again to test.
• C. Follow PPE procedures only.
• D. De-energize the equipment, apply lockout/tagout, and verify zero energy.

Answer: (D)

Safe isolation of energy sources before servicing is the key idea. You must first de-energize the equipment to stop any power flow, then apply a lockout device and attach a tag to indicate the equipment is locked out and who is responsible. The lockout creates a physical barrier that prevents re-energizing, and the tag communicates important safety information. After locking out, you verify zero energy to confirm there is no residual or stored energy left that could cause unexpected energization during the work. This sequence is essential because it provides a real, tangible protection against accidental startup, which PPE or warning tags alone cannot guarantee.

Choosing tagging without a lockout leaves a vulnerability—tags can be ignored or removed, but a lock physically prevents the energy source from being reactivated. Energizing again to test defeats the purpose and introduces risk while service is underway. Relying solely on PPE addresses personal protective measures but does not control the energy sources themselves.