Regulations for Lighting Flexes on Suspended Ceilings

Lighting Flexes

• The cables that connect the lights in a suspended ceiling to the home's electrical circuits are called "flexes," "whips" or sometimes just "cables." The cables are hollow, flexible metal tubes that allow you to move the lights. Electrical codes require a cable that's not easily damaged if it's moved or subjected to abuse that might damage it. Lighting flex lengths and the maximum distance from fixture to junction box is 6 feet.

Cable Types

• Two cable types are allowed for use in suspended ceiling lighting. Type AC is armored cable that has two or three insulated wires wrapped in paper inside the flexible metal tube. The metal tube acts as the ground conductor in conjunction with a metal bonding strip. Type MC is a metal-clad cable and it also has two or three insulated wires for carrying current. An additional wire with green insulation is used for the ground conductor. The metal sheathing on MC may not act as ground.

Cable Connections

• The cables must connect to fixture wiring boxes and ceiling junction boxes with approved connectors. At each connector, a red plastic bushing that protects the wires from damage is required. The red color makes them easily visible to building inspectors. For type AC cable, the bonding strip must bend back over the metal armor after the bushing is installed. The metal connector fits over the armor and makes contact with the bonding strip.

Grounding

• All fixtures, metal junction boxes and metal wiring boxes must be grounded. The green ground wire in type MC cable must connect to the metal wiring box and junction-box grounding screws. For type AC cable, the ground connection from the junction box to the fixture wiring box is made through the cable sheathing, connectors and the bonding strip. The bare ground wire must connect to the metal junction box when type NM cable connects the junction box to the house wiring.