CME Special Occupancies and Equipment 2

Question 1

In a Class II, Division 1 location involving combustible dust, what type of enclosure is required for electrical equipment?

Accepted Answer

Dust-ignitionproof

Answer

Class II locations involve combustible dust hazards, requiring dust-ignitionproof enclosures that prevent dust entry and any internal arcing from igniting surrounding dust.

Question 2

Under NEC Article 517, the critical branch of a hospital's essential electrical system must restore power within how many seconds of interruption?

Accepted Answer

10 seconds

Answer

NEC 517.31(B) requires the critical branch to be restored within 10 seconds, as it serves life-safety loads such as critical care areas and task illumination.

Question 3

Class III hazardous locations are characterized by the presence of:

Accepted Answer

Ignitable fibers or flyings

Answer

Class III locations are those where ignitable fibers or flyings are present but not likely to be in suspension in sufficient quantities to produce ignitable mixtures.

Question 4

Under the NEC Article 505 Zone system, equipment used in a Zone 0 location must be classified as:

Accepted Answer

Category 1

Answer

Zone 0, where explosive atmospheres are continuously present, requires Category 1 equipment providing the highest protection level for continuous ignition risk.

Question 5

NEC 517.20 requires what protection for receptacles and fixed equipment in wet procedure locations of healthcare facilities?

Accepted Answer

Isolated power system or GFCI protection

Answer

NEC 517.20 requires wet procedure locations to use either an isolated power system or GFCI protection to safeguard patients from electric shock.

(CME) Certified Master Electrician Practice Test

(CME) Certified Master Electrician Practice Test

CME Special Occupancies and Equipment 2