What is the purpose of lockout/tagout (LOTO) when servicing high‑voltage systems?

• A. To physically prevent re-energization of the HV system while work is in progress, by applying a lock and tag with your identity and the work to be performed.
• B. To reset the battery.
• C. To secure the vehicle keys in a locked box.
• D. To ensure faster service.

Answer: (A)

Lockout/tagout is about protecting workers by preventing the high‑voltage system from being re-energized while maintenance is underway. A lock is placed on the energy source and a tag is attached with the maintainer’s name and the work being performed. This combination both physically prevents someone from restarting the equipment and clearly communicates who is responsible for the isolation and what work is happening. The procedure usually involves de-energizing the circuit, isolating it, and verifying zero energy, including managing any stored or capacitive energy. Work proceeds only while the lock stays in place, and the lock is removed solely by the person who applied it, ensuring someone is always accountable for re-energizing the system. This focus on controlled energy release protects against electric shock, arc flash, and other hazards during servicing.

Other options don’t address hazardous energy control: resetting the battery, securing vehicle keys, or aiming for faster service do not provide the safeguards needed to prevent unexpected energization and related injuries.