Which cables require fireproof cable trays

Fireproof cable trays are primarily used for power, control, and instrumentation cables that are UL-listed and rated for flame retardance or exposure, such as Type TC, TC-ER, and ITC cables.

Common Cable Types

1. Type TC (Tray Cable) – These are factory-assembled cables with two or more insulated conductors, optionally including grounding conductors, under a non-metallic jacket. They are rated for 600 volts and are suitable for industrial power or control circuits where flame retardant properties are required. TC cables can be installed in cable trays, raceways, and supported outdoor locations. TC-ER (Exposure Rated) variants allow short unsupported transitions from the tray to equipment, up to six feet, while maintaining fire safety and mechanical protection .

2. Type ITC (Instrumentation Tray Cable) – These cables are used for instrumentation and control applications. They may be shielded or unshielded, consist of multiple single conductors or twisted pairs, and can include metal armor. ITC cables are designed to maintain signal integrity and resist fire propagation in critical control systems .

3. Metal-Clad (MC) Cables – MC cables are sometimes used in conjunction with tray cables for 600-volt motor power circuits. They provide additional mechanical protection and can be installed in fireproof trays where required .

Fireproofing Considerations

• Fireproof cable trays are designed to contain flames and prevent fire spread along combustible cable sheaths and insulation .
• Fireproof trays are often used in high-risk or critical environments, such as hospitals, power plants, substations, industrial facilities, and offshore installations .
• Protective measures include fire-resistant coatings, tapes, or bandages applied to cables, as well as fire-rated penetration seals where trays pass through walls or floors .
• Only UL-listed and tray-rated cables should be installed in fireproof trays to ensure compliance with NEC Section 392.10 and maintain circuit integrity during a fire .

Summary

In practice, fireproof cable trays are used for cables that require flame retardance, mechanical protection, and regulatory compliance, including Type TC, TC-ER, ITC, and sometimes MC cables. These trays are critical in environments where fire containment is essential, ensuring that both power and control circuits remain operational and safe during fire incidents .