USCG Exam PracticeElectrical troubleshooting and maintenance
An electrician is selecting an enclosure for a motor controller to be installed in a machinery space with oil mist present. Under 46 CFR §111.95-3, the selection criterion for the enclosure type is which of the following?
- ✓ The enclosure must be constructed to the appropriate NEMA or IEC degree of protection for the service and environment in which it is installedCorrect
- B. The enclosure must be constructed of stainless steel regardless of the ambient environment
- C. The enclosure must be rated for the full system fault current as its primary selection criterion
- D. The enclosure type is at the discretion of the chief engineer provided it is watertight
Why A is correct
46 CFR §111.95-3(a) requires that each electrical component, including motor controllers, be constructed to the appropriate NEMA or IEC degree of protection requirement for the service and environment in which it is installed. Material, fault current rating, and chief engineer discretion are not the governing criteria stated in this section.
Cited:46 CFR §111.95-3