Type TC cable is most commonly known as “tray cable,” a name that reflects its primary use: installation in cable trays found in industrial and commercial settings. You may also see it referred to by its UL listing designation, UL Type TC (1277), or by one of its rated subtypes like TC-ER, TC-LS, or TC-CIC depending on the cable’s specific construction and intended application.
Why It’s Called Tray Cable
The “TC” in Type TC literally stands for “tray cable.” Cable trays are the open, ladder-like or solid-bottom raceways mounted along ceilings and walls in factories, power plants, and large commercial buildings. Because Type TC cable is engineered and listed specifically for installation in these trays, the industry shorthand “tray cable” became its universal nickname. If you hear an electrician or engineer say “tray cable,” they mean Type TC.
Common Subtypes and Their Names
Type TC is really a family of cables, and each subtype adds a suffix that tells you what extra capability it has:
- TC-ER (Exposed Run): The most widely referenced variant. The “ER” means the cable has been tested to withstand the same crush and impact forces as metal-clad (MC) cable. That toughness allows it to be used outside a cable tray in certain situations, which standard TC cable cannot do. In industrial settings, TC-ER can run exposed between a cable tray and equipment for up to 6 feet without continuous support, as long as it isn’t subject to physical damage and the minimum bending radius is maintained.
- TC-LS (Low Smoke): Built with jacket materials that produce limited smoke and corrosive gases when exposed to fire. This matters in enclosed spaces like tunnels, transit systems, and buildings where smoke could endanger occupants.
- TC-CIC (Control Instrumentation Cable): Designed for control and instrumentation circuits, typically carrying low-voltage signals rather than power.
When ordering or specifying cable, you’ll often see these suffixes combined with the manufacturer’s part number. The suffix is what tells you the cable’s rating and where it can legally be installed under the National Electrical Code.
Where Type TC Cable Is Used
Type TC tray cable is a workhorse in industrial environments. It’s UL listed for use in Class 1, Division 2 hazardous locations, which are areas where flammable gases or vapors might be present under abnormal conditions but not during normal operations. That rating makes it common in oil refineries, chemical plants, and manufacturing facilities.
Under NEC Article 336, standard Type TC cable must be installed in a cable tray or raceway. The TC-ER variant opens up more flexibility. In industrial facilities where only qualified personnel service the installation, TC-ER can be run exposed as long as it’s continuously supported and protected against physical damage, secured at intervals no greater than 6 feet.
TC-ER has even made its way into residential construction. A version marked “TC-ER-JP” (the JP stands for its suitability for pulling through joists and studs) can be used as interior wiring in one- and two-family homes. These cables undergo additional testing similar to nonmetallic-sheathed cable (the familiar Romex-style wiring) to ensure they can handle being pulled through staggered holes in structural framing without damage. When used in a dwelling, TC-ER must be installed following the same rules that govern standard nonmetallic-sheathed cable.
How TC Differs From MC Cable
Because TC-ER is tested to the same crush and impact standards as MC cable, the two are sometimes confused. The key difference is construction. MC cable has a metal armor sheath, while TC cable uses a nonmetallic outer jacket, typically a thermoplastic or thermoset material. TC cable is generally lighter, more flexible, and easier to terminate. However, standard TC (without the ER rating) is more restricted in where it can be installed, since it lacks the physical toughness that the metal armor or the ER crush testing provides.
If you’re specifying cable for a project, the name on the jacket tells you everything: “Type TC” means tray cable for use in cable trays, and any suffix after it defines the additional environments and installation methods the cable is rated for.