Which steps are part of lockout/tagout procedures before maintenance?

• A. Tag only without isolating.
• B. Rely on watchdog to monitor.
• C. Just shut down the machine and leave it.
• D. Isolate energy sources, apply lockout/tagout, test for zero energy.

Answer: (D)

Lockout/tagout controls energy so maintenance can be done safely without the machine starting or releasing stored energy. The essential steps are to identify all energy sources, shut the machine down, isolate those energy sources, apply lockout devices or tags to prevent re-energizing, and then test to confirm there is zero energy before work begins. This sequence ensures there’s no accidental startup and no release of stored energy while someone is working. Tagging alone doesn’t physically isolate the equipment, relying on a watchdog isn’t a formal protective measure, and simply shutting down and leaving does not guard against unexpected re-energization or stored energy.