What kind of cables are typically carried in cable trays

Tray cables (TC, TC-ER, and ITC) are the primary types of cables designed for safe and code-compliant installation in cable trays.

General Overview

Cables installed in cable trays must be UL listed and marked as cable tray rated, ensuring they meet standards for flammability, mechanical resistance, and temperature limitations. They are typically protected by a plastic jacket or metal armor and can be rated for indoor, outdoor, corrosive, or hazardous environments. Cable tray-rated cables may also include crush and impact resistance and, in some cases, an exposure rating (ER) allowing short unsupported runs outside the tray .

Common Types of Tray Cables

1. TC – Tray Cable (NEC Article 336)
   • Multi-conductor cables with or without grounding conductors under a non-metallic jacket.
   • Rated for 600 volts, suitable for industrial power or control circuits.
   • Can be installed in cable trays, raceways, and outdoor locations if supported.
   • Flame-retardant and UL listed for hazardous locations and control circuits.
   • Direct burial is allowed if specifically rated .
2. TC-ER – Tray Cable with Exposed Run Rating
   • Designed for short exposed runs (up to 6 feet) between the tray and equipment.
   • Includes impact- and crush-resistant jacketing.
   • Eliminates the need for conduit in certain installations while maintaining code compliance .
3. ITC – Instrumentation Tray Cable (NEC Article 727/725)
   • Used for low-energy control, signal, and communication circuits (typically ≤150 volts, 5 amps).
   • Available in shielded or unshielded constructions, often with twisted pairs and optional metal armor.
   • Provides enhanced noise resistance for sensitive instrumentation and PLC/DCS systems.
   • Some ITC cables also have ER ratings for short exposed runs .

Key Considerations

• Voltage and Application: Ensure the cable type matches the voltage and purpose (power, control, or instrumentation).
• Environmental Conditions: Select cables rated for indoor/outdoor use, moisture, chemicals, or high electrical noise.
• Mechanical Protection: Use cables with crush and impact resistance where physical damage is possible.
• Code Compliance: Follow NEC Section 392 and relevant articles for installation, fill capacity, and support requirements . By selecting the appropriate TC, TC-ER, or ITC cables, you ensure safe, durable, and code-compliant installations in cable tray systems across industrial, commercial, and utility environments.