Fan cable routing via fire cable tray

Fan cables should be routed in fire-rated cable trays with proper separation, firestopping, and support to ensure safety, compliance, and maintainability.

Cable Tray Selection and Layout

When routing fan cables, select a tray type and material suitable for the environment: painted or galvanized steel for indoor use, hot-dip galvanized or stainless steel for outdoor, and aluminum or fiberglass-reinforced plastic for corrosive or high-humidity areas. The tray should be sized to accommodate the number and weight of cables, ensuring mechanical strength to prevent deformation under full load. Plan the shortest and straightest path for the tray, avoiding unnecessary crossings or detours.

Maintain segregation between power and signal cables to minimize electromagnetic interference, using separate trays if necessary. For instrumentation or control fan cables, consider ventilated or solid-bottom trays depending on heat generation and protection requirements.

Fire-

Resistive Cable Requirements

Fan cables installed in fire-rated trays should comply with fire-resistive standards, such as UL 2196 or NFPA 130, ensuring at least 1 hour of fire resistance for emergency circuits. Cables must be supported according to manufacturer instructions and secured to the building structure to prevent movement during a fire. Firestopping at PenetrationsWhere the cable tray passes through walls, slabs, or shafts, firestopping is mandatory.

Use fire-rated boards, firestop packs, mineral wool, or intumescent caulks to seal gaps around the tray. Ensure gaps do not exceed 1 cm² and packing thickness meets minimum requirements (e.g., 24 cm for large openings),. Cover plates should be square, evenly painted, and properly installed to maintain fire integrity.

For larger openings or non-standard tray sizes, consult UL-listed systems or engineering judgment letters to determine the correct number of firestop pillows or putty sticks. Intumescent caulks and mats can provide additional protection by blocking heat penetration and containing smoke.

Installation Best Practices

Maintain minimum bend radius for cables exiting the tray to prevent damage. Use rung spacing of 150–230 mm for ladder trays to support cables evenly. Ensure accessibility for maintenance and future cable additions.

Verify grounding and bonding of the tray system to prevent electrical hazards. By following these guidelines, fan cables routed via fire-rated cable trays will meet safety standards, reduce fire risk, and ensure reliable operation in industrial or commercial installations.