There are a few key terms that apply to all cables, one of the main ones being the type of jacket a cable uses. The jacket is the exterior of the cable and can be made from a variety of materials. It is important to ensure that any cable has the appropriate jacket for the location it will be installed.


PVC (Polyvinyl Chloride), also called CMR (Communications Multipurpose, Riser), cable is the most common cable jacket. This is the type of jacket on a standard cable that you could find off-the-shelf at a store. They are designed with a degree of fire resistance to stop flames from traveling along the cables and spreading through buildings in the event of an emergency. Beyond that, PVC has no special features.


Plenum cables adhere to more strict fire codes than PVC. Commonly used inside walls, ceilings, and floors, plenum cables let off non-toxic smoke when they burn. Fire safety codes often require plenum cables for commercial buildings. If you are unsure whether you need plenum cables, check with your local fire marshall.


Outdoor-rated cables are designed to be used outside, as the name implies. Used in areas such as rooftops and the sides of buildings, these cables are built to hold up against conditions that indoor cables cannot withstand, such as UV radiation (sunlight) and rainwater. If you are putting any type of cable outside, you must use a cable that is at least outdoor rated.

Direct Burial

Direct burial is another “named for what is does” cable. This variant can do everything outdoor cables can do and more. Along with standing up to conditions like direct sunlight, these cables can be buried directly in the ground. Able to withstand groundwater and the pressure of the dirt on top of them, any cable being buried straight into the ground must be direct burial rated to retain integrity. Direct burial cables should be buried 6-8 inches underground and kept a minimum of 6-8 inches away from power lines.