CEI Hazardous Location Wiring 2

Question 1

In a Class I, Division 1 location, which wiring method is permitted for fixed equipment?

Accepted Answer

Threaded rigid metal conduit (RMC)

Answer

Threaded RMC is specifically approved for Class I, Division 1 locations because its threaded connections provide explosion-proof integrity.

Question 2

What does the 'T' temperature code on explosion-proof equipment indicate?

Accepted Answer

Maximum surface temperature the equipment can reach

Answer

The T-code (T1–T6) specifies the maximum surface temperature of the equipment, which must be below the ignition temperature of the hazardous atmosphere.

Question 3

Which NEC article primarily covers Class I, Zone 0, Zone 1, and Zone 2 hazardous locations?

Accepted Answer

Article 505

Answer

Article 505 covers Class I, Zone 0, 1, and 2 locations using the IEC zone system as an alternative to the Division system in Article 501.

Question 4

A seal fitting in a Class I hazardous location conduit run must be installed within how many inches of an explosion-proof enclosure?

Accepted Answer

18 inches

Answer

Per NEC 501.15, seals must be installed within 18 inches of explosion-proof enclosures to prevent flame propagation through conduit.

Question 5

Which Group classification applies to acetylene in hazardous location wiring?

Accepted Answer

Group A

Answer

Acetylene is classified as Group A, the most sensitive group, due to its extremely low ignition energy and wide flammability range.

(CEI) Certified Electrical Inspector Practice Test

(CEI) Certified Electrical Inspector Practice Test

CEI Hazardous Location Wiring 2