Q. When installing metal-armored cables and metal raceways, is it permissible to connect a metal-armored cable or a metal raceway to a nonmetallic box?

  1. Yes, as long as the armored cable is BX cable or equivalent. There is an internal equipment grounding conductor, however, there is no internal bonding means available to bond the armored cables together.
  2. Yes, as long as the raceway is flexible metal conduit or liquidtite flexible metal conduit installed in a length not to exceed 6 feet. There is no internal equipment grounding conductor or and no bonding means available to bond the cables together.
  3. Yes. Where internal bonding means are provided between all entries, nonmetallic boxes shall be permitted to be used with metal raceways or metal-armored cables.
  4. No way! This is not going to happen according to the rules of the NEC.
Answer: C

As per 314.3, “Nonmetallic boxes shall be permitted only with open wiring on insulator, concealed knob-and-tube wiring, cabled wiring methods with entirely nonmetallic sheaths, flexible cords, and nonmetallic raceways.”

Exception No. 1: Where internal bonding means are provided between all entries, nonmetallic boxes shall be permitted to be used with metal raceways or metal-armored cables.

Exception No. 2: Where integral bonding means with a provision for attaching an equipment bonding jumper inside the box are provided between all threaded entries in nonmetallic boxes listed for the purpose, nonmetallic boxes shall be permitted to be used with metal raceways or metal-armored cables.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.