What is UL 1277? The Standard for Type TC-ER Tray Cable

What is UL 1277? The Standard for Tray Cable (Type TC)

In industrial facilities, power doesn’t just run through conduits—it often runs through overhead metal trays. UL 1277 is the standard that ensures Type TC (Tray Cable) can handle the mechanical and environmental stresses of being installed in a tray system without the protection of a pipe.

The Construction Essentials

To meet UL 1277, the cable must be an assembly of two or more insulated conductors with an overall nonmetallic jacket.

• The "ER" Rating (Exposed Run): This is the most sought-after spec for UL 1277 cables. A TC-ER rating means the cable has passed stringent crush and impact tests, allowing it to transition from the tray to the equipment without needing conduit (up to a certain length per NEC).

• Insulation: The internal conductors are usually THHN/THWN-2 (UL 83) or XHHW-2 (UL 44).

• Jacket: Typically heavy-duty PVC or CPE that is sunlight-resistant and flame-retardant.

Why Installers Choose UL 1277 (TC-ER)

• Labor Savings: Being able to run cable without bending and installing conduit saves massive amounts of time and money on a job site.

• Flame Spread Prevention: UL 1277 cables must pass the UL 1685 or IEEE 1202 vertical tray flame test, ensuring the cable won't act as a wick for fire in a vertical shaft.

• Direct Burial: Many TC-rated cables are also listed for direct burial, making them the ultimate "multi-tool" for industrial power.

How Wire America Can Help

At Wire America, we specialize in Type TC-ER Tray Cable for control, signal, and power applications.

• Control & Power: We supply everything from multi-conductor 18 AWG control cables to heavy 500 kcmil power feeders.

• Versatile Jackets: Our TC-ER cables are sunlight-resistant and rated for direct burial, giving you the flexibility to go from underground to overhead in one pull. Because we offer our tray cable by the foot, you get the exact amount you need for your industrial run without paying for excess reel weight.