Which system is used to physically isolate energy during servicing electrical equipment?

• A. Guarding
• B. Lock out tag out
• C. Signage
• D. Housekeeping

Answer: (B)

Lockout/Tagout is the system used to physically isolate energy during servicing electrical equipment. It works by placing locking devices on energy-isolating devices (like disconnect switches or valves) so the equipment cannot be re-energized while work is done. The lock provides a real, physical barrier to prevent energization, while the accompanying tag communicates who is servicing and that the equipment must not be operated until the lock is removed. This approach covers all energy sources, including stored or residual energy, ensuring a worker won’t be exposed to unexpected startup or energy release. Guarding protects workers by creating barriers to moving parts but does not actually isolate energy. Signage offers warnings without stopping energy, and housekeeping focuses on keeping the area orderly rather than controlling energy flow.