Wiring Methods & Materials Flashcards

Type MC cable installed in a wet location must be which of the following?

Answer: Listed and identified for use in wet locations

NEC 330.10(A)(11) requires Type MC cable used in wet locations to be listed and identified for use in wet locations.

What is the minimum size equipment grounding conductor required for a circuit protected by a 100A overcurrent device?

Answer: 8 AWG copper

NEC Table 250.122 requires a minimum 8 AWG copper equipment grounding conductor for circuits with 100A overcurrent protection.

Nonmetallic-sheathed cable (NM) is NOT permitted to be installed in which of the following?

Answer: Buildings exceeding three floors above grade

NEC 334.10 restricts Type NM cable use and prohibits it in buildings exceeding three floors above grade.

When RMC passes through a concrete floor slab, which of the following is required at the termination above the slab?

Answer: A bushing or equivalent protection

NEC 344.46 requires a bushing or equivalent protection at the end of RMC where it emerges from a floor slab to protect conductors from abrasion.

What is the maximum length of a flexible metal conduit (FMC) connection at a luminaire in a ceiling assembly?

Answer: 6 feet

NEC 348.20(A) permits FMC in lengths not exceeding 6 feet for connection of luminaires within a ceiling assembly.

Which conductor insulation type is rated for use in a dry location only?

Answer: TW

NEC Table 310.4 lists TW insulation as rated for 60°C in wet or dry locations, but older TW (not wet-rated) applies only to dry — THWN-2 and XHHW-2 are wet-rated; TW without wet listing is dry only.

When Type NM cable is run across the top of floor joists in an accessible attic, what protection is required within 6 feet of the attic access opening?

Answer: Guard strips at least as high as the cable

NEC 334.23(A) requires guard strips at least as high as the cable when NM cable runs across the top of floor joists within 6 feet of the scuttle hole or attic entrance.