Journeyman Electrician Exam (NEC)Wiring Methods and MaterialsMedium
A commercial electrician is installing a new 20-amp, 120-volt branch circuit in a suspended ceiling. The circuit is run using Type MC cable. What is the maximum distance the MC cable can be supported from a box or conduit body?
- A24 inches
- B6 inches
- C12 inches
- D18 inches
Show answer & explanationAnswer & explanation
Correct answer: C. 12 inches
According to NEC 330.30(C), Type MC cable must be secured within 12 inches of every box, cabinet, or conduit body. This ensures proper support and strain relief at termination points.
Why the other options are wrong
- A. Incorrect. This distance is too long and does not meet the NEC requirement for MC cable support from a box.
- B. Incorrect. This distance is too short and not specified in the NEC for MC cable support from a box.
- D. Incorrect. This distance is too long and does not meet the NEC requirement for MC cable support from a box.
MC Cable Support at Terminations
The NEC requirement specifying the maximum distance Type MC cable can be unsupported from a box, cabinet, or conduit body.
- Ensures mechanical integrity at connection points.
- Prevents strain on conductors and terminations.
- Specific distances are outlined in NEC Article 330.
Memory trick: MC Cables Must Connect Closely.