ANSI NEIS 120-2012 pdf download Installing Armored Cable (AC) and Metal-Clad Cable (MC)
5.1 Description Type MC cable is a factory assembly of one or more insulated current-carrying conductors and one or more equipment grounding conductors (if required) in an overall metallic sheath. MC cable is manufactured with three different types of armor in the following configurations: 1. Interlocking metal-tape (steel or aluminum) – (MCI) 2. Interlocking metal-tape (steel or aluminum) Armor ground – (MCI-A) 3. Smooth metal tube (aluminum only) – (MCS) 4. Corrugated metal tube (copper or aluminum) – (MCC) Type MC cable consists of one or more current- carrying conductors, one or more equipment grounding conductors if required, and in some cases optical fibers. MC cables containing optical fibers are designated Type MC-OF and are considered composite cables in accordance with NEC Article 770.
5.2 Conductors
a) Branch circuits, Feeders, and Services. Type MC cable is permitted to contain conductors from 18 AWG through 2000 kcmil for copper and 12 AWG through 2000 kcmil for aluminum. Typical branch circuit Type MC cables have copper conductors with THHN, THHN/THWN/THWN-2 or XHHW/ XHHW-2 insulation and are suitable for circuits up to 600 volts. Typical feeder and service size Type MC cables have aluminum or copper conductors with THHN/THWN-2 or XHHW/XHHW-2 insulation and are suitable for circuits up to 600 volts. Higher voltage constructions and other insulation types may be available.
b) Medium voltage. Type MV cables are available with conductor insulations rated from 2,400 to 35,000 volts and may be marked for use as Type MC cables. c) Fire alarm. Type MC cables intended for fire alarm/control applications have TFN, TFFN, THHN or other suitable insulation.
5.3 Special MC Cable Configurations In addition to “standard” configurations used for services, feeders and branch circuits, MC cables are manufactured for the following specific applications: Fire Alarm. This Type MC cable is manufactured with either steel or aluminum armor and contains 18 through 10 AWG copper conductors with TFN, TFFN, or THHN insulation. Other appropriate conductor insulations may be used. In addition, the cable contains a bare or insulated equipment grounding conductor. Install according to NEC Article 760 or NFPA 72 National Fire Alarm and Signaling Code.