USCG Exam PracticeSwitchboards and distribution systems
Under 46 CFR §111.95-3, which statement correctly describes the locking requirement for a main line emergency disconnect switch that is accessible to an unauthorized person?
- A. The switch must be lockable in both the open and closed positions using a padlock
- ✓ The switch must have a means to lock it in the open-circuit position only; it must not lock in the closed-circuit positionCorrect
- C. The switch must be lockable in the closed-circuit position to prevent unauthorized de-energization
- D. The switch must be secured behind a locked enclosure door; no locking of the switch mechanism itself is required
Why B is correct
46 CFR §111.95-3(b) requires that a main line emergency disconnect switch accessible to unauthorized persons have a means to lock it in the open-circuit position with a padlock or equivalent, and explicitly states the switch must not lock in the closed-circuit position.
Cited:46 CFR §111.95-3