Red Seal Electrician Practice
Safety and work practicesQuestion 607 of 1506

Three workers each lock out the same disconnect with a personal padlock. When can the system be re-energized?

  1. After the first worker has removed his or her lock.
  2. After the supervisor has removed all three locks.
  3. As soon as the last worker has finished the job.
  4. Only after all three have removed their own locks.
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Correct answer: Only after all three have removed their own locks.

The system stays in a Zero Energy State until every lock is off, so each worker must give consent.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 3.5: Safe Practices

Practice safety and work practices

Questions last reviewed: 18 October 2026