Wiring Methods and Materials Flashcards
7 cards from real Licensed Electrical Contractor practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Wiring Methods and Materials flashcards as text
Which of the following is a requirement for installing armored cable (Type AC) in a residential attic accessed by a permanent ladder?
Answer: Cable within 6 feet of the scuttle hole must be protected
NEC 320.23(A) requires Type AC cable within 6 feet of the attic scuttle hole or entrance to be protected by guard strips or run through conduit.
The ampacity of conductors bundled in a raceway must be derated when the number of current-carrying conductors exceeds:
Answer: 3
Per NEC 310.15(C)(1), ampacity derating applies when more than 3 current-carrying conductors are bundled or installed in a conduit together.
Which wiring method is required when installing conductors in a corrosive chemical storage area?
Answer: Rigid nonmetallic conduit (PVC)
NEC 300.6 and Article 352 allow rigid nonmetallic conduit (PVC) in corrosive environments where metallic raceways would be damaged.
What is the maximum support spacing for rigid PVC conduit (Schedule 40) with a trade size of 1 inch?
Answer: 4 feet
NEC Table 352.30(B) requires 1-inch PVC conduit to be supported at intervals not exceeding 4 feet.
Type MI (mineral-insulated) cable is uniquely suited for which application?
Answer: High-temperature and fire-rated circuit applications
Type MI cable uses magnesium oxide insulation enclosed in a metal sheath, making it suitable for high-temperature environments and fire-rated circuit installations per NEC Article 332.
When is a conduit seal (sealing fitting) required on a conduit entering a panelboard from a wet or damp location?
Answer: When the conduit enters from outside or a wet location to prevent moisture migration
NEC 230.8 and 300.5(G) require conduit seals where conduits enter from wet or underground locations into enclosures to prevent moisture and gases from migrating indoors.
What is the color code for a 208Y/120V, 3-phase, 4-wire system's high-leg conductor?
Answer: Orange
NEC 230.56 requires the high-leg (wild leg) of a 4-wire delta system to be identified with orange color to warn that it has a higher voltage to ground (~208V).