COMMERCIAL ELECTRICAL WIRING ELITE
REVIEW COMPREHENSIVE STUDY PAPER WITH
VERIFIED SOLUTIONS
◉The proper size and type of conductor must be installed to comply
with manufacturers installation instructions (True) (False) Answer:
True
NEC 110.3(B)
Pg. 51
◉Ampacities of NEC Table 310.16 is based on not more than
___________ current-carrying conductors in a raceway, cable, or earth
based on an ambient temperature of __________ degrees F. Answer: 1.
Not more than three current carrying-conductors in a raceway, cable, or
earth based on ambient temperature of
2. 30 degrees C (86 degrees F)
pg. 52
◉Conductors with a -2 insulation designation have a (higher) (lower)
ampacity in a wet location than do conductors without the designation.
Answer: Have a higher ampacity in wet locations than conductors
without the designation.
pg. 52
, ◉For the same size of the conductor, aluminum conductors have a
(higher) (lower) ampacity then do copper conductors. Answer:
Aluminum conductors have lower ampacity than copper conductors.
Pg. 54
◉Describe what the following conductor designation means when it is
printed on the insulation; RHH/RHW/USE Answer: Triple-rated
USE = direct burial
RHH = in or on buildings or structures in dry locations at 90 degree
ampacities.
RHW = in or on buildings or structures in wet locations at 75 degrees
ampacities
◉Which of the following two insulation types are more likely to soften
when heated?
1. THWN 2. XHHW Answer: THWN
Reason: thermoplastic insulation if heated above its rated temperature
can soften and melt.
Pg. 54
REVIEW COMPREHENSIVE STUDY PAPER WITH
VERIFIED SOLUTIONS
◉The proper size and type of conductor must be installed to comply
with manufacturers installation instructions (True) (False) Answer:
True
NEC 110.3(B)
Pg. 51
◉Ampacities of NEC Table 310.16 is based on not more than
___________ current-carrying conductors in a raceway, cable, or earth
based on an ambient temperature of __________ degrees F. Answer: 1.
Not more than three current carrying-conductors in a raceway, cable, or
earth based on ambient temperature of
2. 30 degrees C (86 degrees F)
pg. 52
◉Conductors with a -2 insulation designation have a (higher) (lower)
ampacity in a wet location than do conductors without the designation.
Answer: Have a higher ampacity in wet locations than conductors
without the designation.
pg. 52
, ◉For the same size of the conductor, aluminum conductors have a
(higher) (lower) ampacity then do copper conductors. Answer:
Aluminum conductors have lower ampacity than copper conductors.
Pg. 54
◉Describe what the following conductor designation means when it is
printed on the insulation; RHH/RHW/USE Answer: Triple-rated
USE = direct burial
RHH = in or on buildings or structures in dry locations at 90 degree
ampacities.
RHW = in or on buildings or structures in wet locations at 75 degrees
ampacities
◉Which of the following two insulation types are more likely to soften
when heated?
1. THWN 2. XHHW Answer: THWN
Reason: thermoplastic insulation if heated above its rated temperature
can soften and melt.
Pg. 54
