CSLB C-10 Electrical ContractorWiring Methods and MaterialsMedium
An electrician examines a metal-jacketed cable that contains a thin aluminum bonding strip running the full length inside the spiral metal armor, providing supplemental grounding continuity along with the armor itself. This describes which cable type?
- AType NM cable
- BType MC cable
- CType SE cable
- DType AC cable
Show answer & explanationAnswer & explanation
Correct answer: D. Type AC cable
Type AC (armored) cable includes an internal aluminum bonding strip in contact with the spiral steel armor to ensure a low-impedance grounding path, as required by NEC 320.108. MC cable instead typically includes a separate, full-sized insulated or bare equipment grounding conductor rather than relying on a thin bonding strip.
Why the other options are wrong
- A. NM cable is nonmetallic and has no metal armor or bonding strip.
- B. MC cable generally uses a discrete grounding conductor, not a thin internal bonding strip.
- C. SE cable is service-entrance cable and does not use this armor/bonding-strip construction.
AC Cable Bonding Strip
Type AC cable includes an internal aluminum bonding strip in contact with its spiral metal armor, providing an effective grounding path per NEC 320.108.
- Distinguishes AC cable from MC cable construction
- Armor plus bonding strip together serve as the equipment ground
- MC cable usually has a separate grounding conductor instead
Memory trick: 'AC = Aluminum strip inside the Coil.'