National Electric Code NEC - Article 310
The ampacity of a conductor can be different along the length of the conductor. The higher ampacity can be used beyond the point of transition for a a distance of no more than ____ ft, or no more than ____ percent of the circuit length figured at the higher ampacity, whichever is less. (a) 10, 10 (b) 10, 20 (c) 15, 15 (d) 20, 10
(a) 10, 10 - Reference NEC 2017 310.15 (A)(2)
The minimum size conductor permitted for branch circuits under 600V is ____ AWG. (a) 14 (b) 12 (c) 10 (d) 8
(a) 14 - Reference NEC 2017 Table 310.106(A)
Conductors shall be permitted for use in any of the wiring methods recognized in Chapter 3 and as permitted in the NEC. (a) True (b) False
(a) True - Reference NEC 2017 310.10
Where conductors in parallel are run in separate raceways, the raceways shall have the same electrical characteristics (a) True (b) False
(a) True - Reference NEC 2017 310.10 (H)(3)
No conductor shall be used where its operating temperature exceeds that designated for the type of insulated conductor involved. (a) True (b) False
(a) True - Reference NEC 2017 310.15 (A)(3)
Each current-carrying conductor of a paralleled set of conductors shall be counted as a current-carrying conductor for the purpose of applying the adjustment factors of 310.15(B)(3)(a) (a) True (b) False
(a) True - Reference NEC 2017 310.15 (B)(2)
On a three-phase, 4-wire, wye circuit, where the major portion of the load consists of nonlinear loads, the neutral conductor shall be counted when applying 310.15 (B)(3)(a) adjustment factors. (a) True (b) False
(a) True - Reference NEC 2017 310.15 (B)(5)(c)
When determining the number of current-carrying conductors, a grounding or bonding conductor shall not be counted when applying the provisions of 310.15 (B)(3)(a). (a) True (b) False
(a) True - Reference NEC 2017 310.15 (B)(6)
A ____ conductor that carries only the unbalanced current from other conductors of the same circuit shall not be required to be counted when applying the provisions of 310.15 (B)(3)(a). (a) neutral (b) ungrounded (c) grounding (d) none of these
(a) neutral - Reference NEC 2017 310.15 (B)(5)
Conductor adjustment factor shall not apply to conductors in raceways having a length not exceeding ____ in. (a) 12 (b) 24 (c) 36 (d) 48
(b) 24 - Reference NEC 2017 310.15 (B)(3)(a)(2)
THW insulation has a ____ rating when installed within electric-discharge lighting equipment, such as through fluorescent luminaires. (a) 60*C (b) 75*C (c) 90*C (d) 105*C
(b) 75*C - Reference Know how to decode cable insulation - The "H" represents 75*C.
Where installed in raceways, conductors ____ AWG and larger shall be stranded. (a) 10 (b) 8 (c) 6 (d) 4
(b) 8 - Reference NEC 2017 310.106 (C)
The ______ rating of a conductor is the maximum temperature, at any location along its length, which the conductor can withstand over a prolonged period of time without serious degradation. (a) ambient (b) temperature (c) maximum withstand (d) short-circuit
(b) temperature - Reference NEC 2017 310.15 (A)(3)
The ampacities listed in 310.15 do not take ____ into consideration. (a) continuous loads (b) voltage drop (c) insulation (d) wet locations
(b) voltage drop - Reference NEC 2017 310.15 (A)(1)
Where six current-carrying conductors are run in the same conduit or cable, the ampacity of each conductor shall be adjusted by a factor of ____ percent. (a) 40 (b) 60 (c) 80 (d) 90
(c) 80 - Reference NEC 2017 310.15 (B)(3)
Which conductor type has an insulation temperature rating of 90*C? (a) THWN (b) RHW (c) THHN (d) TW
(c) THHN - Reference Know how to decode cable insulation - The "HH" represents 90*C.
THWN insulated conductors are rated ____. (a) 75*C (b) for wet locations (c) a and b (d) not enough information
(c) a and b - Reference Know how to decode cable insulation - The "H" represents 75*C and "W" represent wet locations.
There are four principal determinants of conductor operating temperature, one of which is ____ generated internally in the conductor as the result of load current flow, including fundamental and harmonic currents. (a) friction (b) magnetism (c) heat (d) none of these
(c) heat - Reference NEC 2017 310.15 (A)(3)
In general, the minimum size conductor permitted for use in parallel installations is ______ AWG. (a) 10 (b) 4 (c) 1 (d) 1/0
(d) 1/0 - Reference NEC 2017 310.10 (H)
Where conductors are installed in raceways or cables exposed to direct sunlight on or above rooftops, the ambient temperature shall be increased by ____ where the conduits are less than 1/2" from the rooftop. (a) 30*F (b) 40*F (c) 50*F (d) 60*F
(d) 60*F - Reference NEC 2017 310.15 (B)(3)(c)
Parallel conductors shall have the same ______ . (a) length (b) material (c) size in circular mil area (d) all of these
(d) all of these - Reference NEC 2017 310.10 (H)(2)
The ampacity adjustment factors of Table 310.15(B)(3)(a) do not apply to Type AC or Type MC cable without an overall outer jacket, if which of the following conditions are met? (a) Each cable has not more than three current-carrying conductors. (b) The conductors are 12 AWG copper (c) No more than 20 current-carrying conductors are installed without maintaining spacing. (d) all of these
(d) all of these - Reference NEC 2017 310.15 (B)(3)(a)(4)