Approved tray cables include Type TC, TC-ER, PLTC, ITC, and VNTC, each designed for safe installation in cable trays according to NEC standards.

Overview of Tray Cables

Tray cables are multi-conductor or multi-pair cables specifically designed for installation in cable trays without additional conduit. They are widely used in industrial plants, commercial buildings, and utility installations where organized, accessible routing is required for power, control, and instrumentation circuits . Not all cables can be installed in trays; only NEC-listed tray-rated cables are permitted to ensure safety, fire resistance, and mechanical durability .

Common Tray Cable Types

• Type TC (Tray Cable): Standard 600V multi-conductor cable listed under UL 1277. Conductors are typically copper, insulated with THHN, THWN, XHHW, or XLPE, and jacketed with PVC or CPE. Suitable for installation in trays, raceways, and outdoor locations when supported .
• Type TC-ER (Exposed Run): Meets all TC requirements plus additional crush and impact resistance, allowing installation outside trays, along structural members, or in open air without conduit .
• PLTC (Power-Limited Tray Cable): Designed for control and signaling circuits, providing insulation and protection suitable for tray installation under NEC Article 725 .
• ITC (Instrument Tray Cable): Used for instrumentation and control applications, often with additional shielding to reduce electromagnetic interference .
• VNTC (Ventilated Tray Cable): Similar to TC but designed for ventilated trays, allowing better heat dissipation and airflow around the cables .

Key Considerations

• Voltage Class: Ensure the cable type matches the system voltage requirements. TC cables are typically rated for 600V, while PLTC and ITC may have different voltage ratings .
• Environmental Conditions: Material selection (PVC, CPE, XLPE) depends on exposure to moisture, chemicals, or temperature extremes .
• NEC Compliance: Follow NEC Article 392 for cable tray systems, including grounding, bonding, tray fill limits, and separation of power and data cables to prevent interference .
• Mechanical Protection: For exposed runs or areas prone to physical damage, use TC-ER or armored variants to ensure durability .

Summary

For safe and compliant cable tray installations, select NEC-listed tray cables appropriate for the application: Type TC for standard tray runs, TC-ER for exposed installations, PLTC for control circuits, and ITC/VNTC for instrumentation or ventilated tray systems. Proper selection ensures electrical safety, regulatory compliance, and long-term reliability of the installation .