Journeyman Electrician’s Exam Journeyman Electrician's NEC 4

Question 1

Per NEC 240.6, which of the following is NOT a standard ampere rating for fuses and inverse time circuit breakers?

Accepted Answer

35 amperes

Answer

NEC 240.6(A) lists standard ratings and 35 amperes is not among the standard ratings; 40 amperes is the standard rating near that value.

Question 2

According to NEC 314.16, a standard 4-inch square metal box has a volume of approximately 21 cubic inches. Using the box fill calculation, how many #12 AWG conductors (including devices) can this box contain if there are two cable clamps and one receptacle?

Accepted Answer

6 conductors

Answer

Each #12 AWG counts as 2.25 cu in; the two cable clamps = one conductor equivalent (2.25 cu in) and the receptacle = two conductor equivalents (4.5 cu in), leaving 21 - 6.75 = 14.25 cu in for 6 conductors.

Question 3

NEC 230.54 covers service head requirements. In what direction must a service head face to prevent water entry into the service entrance conductors?

Accepted Answer

Facing down or with conductors entering from below

Answer

NEC 230.54(C) requires service heads to be rainproof and located above the point of attachment of the service-drop conductors, with conductors arranged so water cannot enter.

Question 4

Under NEC 250.64(B), aluminum grounding electrode conductors must be protected from corrosive conditions. Aluminum GECs must not be installed within how many inches of the earth?

Accepted Answer

12 inches

Answer

NEC 250.64(B) prohibits aluminum or copper-clad aluminum grounding electrode conductors from being used where within 18 inches of the earth — actually the answer is 18 inches.

Question 5

NEC 410.116 requires recessed luminaires to be thermally protected unless they are Type IC-rated. What does 'IC' stand for in this context?

Accepted Answer

Insulation Contact

Answer

IC stands for Insulation Contact, meaning the luminaire is rated to be in direct contact with thermal insulation without overheating.

Journeyman Electrician’s Exam Practice Test

Journeyman Electrician’s Exam Practice Test

Journeyman Electrician’s Exam Journeyman Electrician's NEC 4