USCG Exam PracticeSwitchboards and distribution systems
What minimum clear working space must be maintained in front of a main distribution switchboard?
- A. 455 millimeters (18 inches).
- B. 305 millimeters (12 inches).
- ✓ 610 millimeters (24 inches).Correct
- D. 760 millimeters (30 inches).
Why C is correct
46 CFR §183.330(e) requires at least 610 millimeters (24 inches) of working space in front of all main distribution panels and switchboards. The 455 mm (18 inch) dimension applies to the required working space behind the switchboard.
Cited:46 CFR §183.330