What cables run in fire cable trays

Fire cable trays are designed to hold cables that are specifically rated for fire resistance, including tray cables (TC), power-limited tray cables (PLTC), instrumentation tray cables (ITC), fire alarm cables (FPL), communication cables (CM), and optical fiber cables (OFN).

Common Cable Types for Fire-Rated Trays

Tray Cable (TC): These are multi-conductor power and control cables with a non-metallic jacket, rated for 600 volts, and often flame-retardant. TC cables can be used in industrial power circuits, control circuits, and hazardous locations if UL-listed and marked for tray use. Type TC-ER (exposure-rated) cables are allowed to extend up to six feet outside the tray if supported and secured . Instrumentation Tray Cable (ITC): Used for instrumentation and control signals, ITC cables can be shielded or unshielded and may include metal armor. They are tested for fire propagation and smoke release, making them suitable for fire-rated trays in industrial and commercial environments . Power-Limited Tray Cable (PLTC): These cables are designed for low-voltage power and control circuits, often used in fire alarm systems or signaling applications. They are UL-listed for tray installation and tested for flame propagation . Fire Alarm Cables (FPL): Specifically designed for fire alarm systems, FPL cables are tested to resist fire and maintain circuit integrity during a fire event. They are commonly installed in fire-rated trays to ensure safety and compliance . Communication Cables (CM) and Optical Fiber Cables (OFN): These cables are also tested for fire propagation and smoke release, allowing them to be safely routed in fire-rated trays alongside power and control cables .

Fire Safety Considerations

• Testing Standards: Cables in fire trays are typically tested using UL 1685 Vertical-Tray Fire-Propagation and Smoke Release Test or equivalent standards such as DIN 4102-12 in Europe .
• Tray Material: Fire-resistant trays may be made of steel, stainless steel, or specialized coatings to withstand high temperatures and prevent fire spread .
• Segregation: Power and signal cables should be routed separately to minimize interference and maintain fire safety .
• Installation: Cables must be secured, supported, and spaced according to NEC Article 392 and manufacturer specifications to prevent overheating and maintain fire integrity .

Industry Examples

Fire-rated cable trays are widely used in construction, power plants, oil and gas, petrochemical, rail, and utility industries. Specific cable systems like Prysmian FP400/FP600 and Draka Firetuf are commonly installed in fire-resistant basket trays such as Cablofil systems, which have been tested for fire durations up to 90 minutes at high temperatures . Key Takeaway: Only cables that are UL-listed, fire-rated, and suitable for tray installation should be placed in fire cable trays. This includes TC, TC-ER, ITC, PLTC, FPL, CM, and OFN cables, ensuring both electrical performance and fire safety compliance.