Guide information for power ventilators for use in hazardous locations
This category covers roof- and wall-mounted power ventilators and duct fans consists of an impeller and motor installed in a housing. Roof- and wall-mounted power ventilators have a weather-resistant housing and are supported by a weather-resistant base intended to fit, usually by means of a curb, over a wall or roof opening.
Ratings
Duct fans intended to move heated air are investigated to determine the effect of heated air on electrical components and are marked with the maximum temperature of the air.
These ventilators are intended for industrial use and are for the purpose of ventilation only. These ventilators consist of exhaust type and makeup air type devices. Makeup air type ventilators are not equipped for evaporative cooling.
Power ventilators intended for use where they will be exposed to weather are investigated to determine the effect of rain on electrical components.
These ventilators have not been investigated for installation in firewalls or from the standpoint of their effect on venting in case of fire. Their location should be determined after consultation with authorities having jurisdiction (AHJs).
These ventilators are not intended for the primary removal of grease-laden vapors and residues over restaurant cooking appliances.
Metallic impellers are constructed of medium brass or aluminum, with hardness not over Rockwell B66. Belt-driven power ventilators are evaluated for the potential risk of ignition from temperature as a result of belt slippage.
Related equipment
Equipment in this category consists of an assembly of UL Listed, Classified and Recognized parts for use in hazardous locations. The basic standards used to investigate equipment in this category are the applicable hazardous locations standards for the parts of the assembly and UL 705, the Standard for Safety of Power Ventilator.
Listing
The UL Listing Mark on the product is the only method provided by UL to identify products manufactured under its Listing and Follow-Up Service. The Listing Mark for these products includes the UL symbol together with the word "LISTED," a control number, and the product name "Power Ventilator for Use in Hazardous Location," or other appropriate product name as shown in the individual Listing.
