CEA Wiring Methods and Materials 4

Question 1

When conductors of different systems share the same raceway, they must all be insulated for the:

Accepted Answer

Highest voltage present

Answer

NEC 300.3(C)(1) requires all conductors sharing a raceway to be insulated for the highest voltage present in that raceway.

Question 2

What is the color code for the high-leg (wild leg) conductor in a 4-wire, 3-phase delta system?

Accepted Answer

Orange

Answer

NEC 230.56 and 408.3(F) require the high-leg conductor in a 3-phase delta system to be identified with orange color.

Question 3

Electrical metallic tubing (EMT) is NOT permitted to be used in which condition?

Accepted Answer

Subject to severe physical damage

Answer

NEC 358.12 prohibits EMT where it will be subject to severe physical damage due to its thin-wall construction.

Question 4

Type MC cable used for wiring in an accessible ceiling plenum space used for environmental air must be which type?

Accepted Answer

MC cable with a smooth or corrugated aluminum sheath or listed plenum cable

Answer

NEC 330.10(A)(11) and 300.22 require cables in air-handling plenums to be plenum-rated or have a metallic sheath that limits flame and smoke spread.

Question 5

A 2-inch rigid metal conduit (RMC) must have a support within what distance of each box, cabinet, or conduit fitting?

Accepted Answer

3 feet

Answer

NEC 344.30(B)(1) requires RMC to be supported within 3 feet of each outlet box, junction box, device box, cabinet, conduit body, or other conduit termination.

(CEA) Certified Electrical Apprentice Practice Test

(CEA) Certified Electrical Apprentice Practice Test

CEA Wiring Methods and Materials 4