Metal clad cable, also known as armored or BX cable, is a flexible metal conduit with a wire bundle, consisting of individually insulated conductors covered by a flexible spiral-wound layer of metal. Most often used for feeder and service power in commercial and multi-story residential applications, the steel or aluminum clad cable is more resistant to damage from puncture or abrasion than non-metallic sheathed cable.
Using a tool called a Roto-Split, the metal sheath of the cable is split to expose the insulated wire. A rotary tool with a cut-off wheel can also be used.
The conductor wires are usually covered in a paper jacket in addition to the wire’s PVC insulation.
A plastic bushing is slid over the end of the metal cladding to prevent the cladding’s sharp edged from damaging the conductor wires’ insulation.
The bare ground wire is wrapped around the metal sheathing at each cut end. Insure the bushing protects the wire’s insulation from the cable’s metal sheath.
The cable is inserted into an electrical box and held in place by a clamp. Final electrical connections can now be made.
Local codes vary on the use of metal clad cable in residential applications. Always check with a local building inspector before beginning a new project.
Credit: Renovate with Tommy Mac