Armored cable is a type of flexible metal hose that is used to protect electrical wiring that runs throughout homes in areas where the building codes requires the use of such protective material. Some cities or municipalities require that metal conduit or armored cable be used to protect the wiring in residential and commercial buildings to help prevent fires. You could have someone install armored cable for; however, doing it yourself is much more rewarding and much easier than you might think. Therefore, use this easy to follow how-to guide to save some money and install armored cable yourself.
Step 1 - Prepare Junction Box
Use a screwdriver to punch out one of the knockout tabs on the junction box where the armored cable will be installed. Insert the screw driver in the crevice and then use it to pry open the knockout tab. Using your fingers worked the knockout tab back and forth until it simply snaps off from the junction box.
Step 2 - Determine Length and Run Armored Cable
Use the measuring tape to estimate how much armored cable will need to be run from the switch box to the main circuit breaker box or to another junction box where it will be installed. If you'll be running the armored cable through studs or walls, it's probably best to simply run the cable from one point to the other before you actually cut the armored cable.
(Tip - if you want to save some time and effort, you can also go ahead and insert your electrical wiring into the armored cable that this point. This will help you avoid having to use a fish tape after you have installed the armored cable.)
Step 3 - Cut and Trim the Armored Cable
Once you have the armored cable in position, use the hacksaw or armored cable cutter to cut the cable. If you're using a hacksaw, cut the cable at approximately a 60 degree angle. Also, allow for an extra 8 to 10 inches of armored cable on either end so that you will have enough to work with when connecting it to the junction box. Then, trim away the steel sheathing from the end of the armored cable so that the bushing papers exposed. Pull away about 1 inch of the bushing paper where the wire will be passed through.
Step 4 - Install Anti-Short Bushing
Place an anti-short bushing at the end of the cable where the cable from the armored cable will meet with the cable inside the junction box. Then, use your fingers to fold back the bonding strip on the bushing.
Step 5 - Attach the Armored Cable Connector
Use a clamp or set screw to attach the connector to the end of the armored cable.
Step 6 - Connect Cable to Junction Box
Thread the connector at the end of the car armored cable into the empty knockout tab on the junction box. Then, pass the wiring through the lock washer and begin to spin it on to the connector in a clockwise direction. Once the lock washer is hand tight, use a hammer and flat head screwdriver to gently tap the lock washer and tighten it securely. You can now connect the wiring from the armored cable to that in the junction box, or you can use a fish tape to pass wiring through the cable at this time.