Sufficient working space must be provided per paragraph 110 26 of the nec.
Electric duct heater installation.
Warren technology produces custom built electric duct heaters for installation in commercial hvac systems.
Warren heaters are engineered for reliability and safety and are specifically designed not to exceed safe operating temperatures.
The heater must always be interlocked with the fan.
A duct heater must be installed according to the installations instructions wiring diagram and labeling supplied with the heater.
2 1 800 627 4499 accessory rh series electric duct heaters warning avertissement arclash and electric shock hazard all models of electric heaters as discussed in this manual.
These duct heaters are not intended for installation in series in the air.
Instruction manual 66 13kb download document.
Never operate a duct heater without airflow.
Custom built electric duct heaters are safety tested and listed by underwriters laboratories ul and the canadian standards agency csa and meet national electric code nec requirements.
Installation instructions 47 66kb download document thermo air.
Duct elbows or turns must be located at least 4 from the inlet of the heater and 2 from the outlet of the heater.