Tray cable, Type TC is an approved wiring method in the NEC found in article 336. It is an efficient method of installing feeders, branch circuits and control cable because multiple runs of tray cable can be installed in one cable support system (i.e. cable tray) rather than multiple conduit runs, which adds to labor and material cost.
Tray cable is a factory assembly of two or more insulated conductors with or without an associated equipment ground conductor under a non-metallic jacket. For feeder and branch circuits, tray cable can be manufactured with any of the insulation types found in NEC 310.4 (A) or (B). Depending on the insulation used, tray cable will have either 600, 1000 or 2000 volt rating. Metallic shields are allowed over groups of conductors or under the outer jacket or both. Metallic sheaths or armor is not allowed under or over the non-metallic jacket, doing so would make the cable type MC cable.
Type TC cable can be used for a variety of applications such as, power, lighting, control, signal circuits, class 1 circuits and non-power limited fire alarm circuits. Tray cable cannot be installed where it is subject to physical damage and must be installed in a cable tray with exceptions. Sections of the tray can have up to one foot breaks or separations without the need of adding protection to the cable in these areas.