Working with Armored Cable: Dos and Don'ts

Cables on a grey background.
  • N/A
  • Intermediate
  • 50
What You'll Need
Armored cable cutter
Anti-short bushing
Flat screwdriver
Support strap

Armored cable is an electrical wiring solution where the ground, the neutral, and the Hot wires are encased in a flexible metal sheathing. It is much more durable and damage resistant than nonmetallic or Romex wire and is approved for use in many more types of construction applications. Although armored cable is tougher than NM cable, it is also harder to work with. Therefore, here are some dos and don'ts for working with an armored cable that will make the job easier and more successful.

Do: Buy an Armored Cable Cutting Tool

If you want to make clean cuts on armored cable, you should invest about $30 to $40 and purchase a specialized armored cable cutting tool. Although this will add slightly to the overall cost of your project, it will allow you to quickly cut the tough metal casing on armored cable and help reduce the amount of time needed to install the cable considerably.

Don't: Use a Hacksaw to Cut Armored Cable

Many people choose to use a hack saw or other cutting tool to cut the armored cable. While this is possible, it is strongly recommended that you don't attempt it. When the armored cable is cut with a hacksaw or other cutting tool, it can result in rough or jagged edges that could damage the insulation in the armored cable or even nick the electrical wires inside the metal sheeting. Nicked wires inside armored cable create a dangerous fire hazard. Refer to the first tip in this article and purchase an armored cable cutting tool.

Do: Always Use Ant-Short Bushings

Anti-short bushings are plastic funnel type items that are inserted at the end of armored cable. The rounded edges of the anti-short bushings help to avoid nicks and cuts in the electrical wire inside the sheeting and also help to better insulate the wiring to prevent arcs or shorts. Never attempt to install armored cable without using anti-short bushings.

Don't: Just Hand-Tighten Lock Nuts

When connecting armored cable to the junction box, you may be tempted to simply hand tighten the lock nut on the threaded portion of the armored cable connector. However, you should always use a flat head screwdriver and hammer to gently tap the lock nut until it is tightened very securely. If you do not, the lock nut may wiggle free overtime and cause a short in your electoral system wiring. In extreme cases, your cable may fall completely out of the junction box and create a very dangerous fire hazard.

Do: Always Use Support Straps for Armored Cable

When installing armored cable, you should place support straps every 24 inches or so to ensure that the weight of the cable is completely supported. Long runs of armored cable can be quite heavy and cause stress on the connector between the cable and the junction box if not supported. You should also place a support strap within about 12 inches of the junction box. The last thing you want is for the weight of the armor cable to cause the connector to fail and allow the cable to fall out of the junction box.