Cable trays can be installed in the air handling room

Section 318-4 Uses Not Permitted states that “Cable tray systems shall not be used in environmental air spaces except as permitted in Section 300-22 to support wiring methods recognized for use in such spaces. Cable tray is a mechanical support system just as strut is a mechanical support system. Plenum-rated Chapter 7 and Chapter 8 wiring methods are permitted in plenum spaces according to the following: (2) Cable Tray Systems. Metal cable tray systems can be installed to. The primary rulebook used in the safe use of cable trays is NEC Article 392. You should consider it as a series of instructions that make the buildings resistant to. Prohibition of Cables Inside Air Ducts: National and local codes strictly forbid running electrical cables within ventilation ducts to prevent fire hazards and obstruction of airflow. [pdf]