CEI Hazardous Location Wiring 3

Question 1

Which NEC article covers Class III hazardous locations involving ignitable fibers and flyings?

Accepted Answer

Article 503

Answer

Article 503 addresses Class III locations where easily ignitable fibers or flyings are present but not likely to be in suspension in hazardous quantities.

Question 2

In a Class I hazardous location, flexible connections to equipment must use which type of fitting?

Accepted Answer

Explosion-proof flexible fittings listed for the location

Answer

Flexible connections in Class I locations require fittings specifically listed as explosion-proof to maintain the integrity of the hazardous location wiring system.

Question 3

What is a Zone 0 hazardous location characterized by?

Accepted Answer

Flammable gases present continuously or for long periods

Answer

Zone 0 is the most hazardous zone where flammable concentrations exist continuously or for long periods during normal operation.

Question 4

When sealing Class I conduit runs, the sealing compound must have a minimum thickness equal to the trade size of the conduit or what minimum value?

Accepted Answer

5/8 inch

Answer

Per NEC 501.15(C), the sealing compound thickness must not be less than the trade size of the conduit and in no case less than 5/8 inch.

Question 5

Which type of motor is NOT permitted in a Class I, Division 1 location?

Accepted Answer

Open drip-proof motor

Answer

Open drip-proof motors expose live parts and arcing contacts to the hazardous atmosphere and are not permitted in Class I, Division 1 locations.

(CEI) Certified Electrical Inspector Practice Test

(CEI) Certified Electrical Inspector Practice Test

CEI Hazardous Location Wiring 3