NFPA 96 Code 18.104.22.168 states: “Approved up-blast fans with motors surrounded by the air stream shall be hinged, supplied with flexible weather proof electrical cable and service hold-open retainers, and listed for this use.”
Trying to remove a heavy exhaust fan from its duct for cleaning or maintenance is not only dangerous for the contractor but always causes some degree of damage to the roof or the fan housing.
Exhaust fan wiring is stretched when the fan is taken off the stack and placed on the roof. Without a hinge kit, the fan wiring is subject to unnecessary abuse during cleaning and maintenance.
The exhaust fan can be damaged over time by removing it from the stack repeatedly and placing it on its side.
To prevent Rooftop damage and leaks can be the result of placing the exhaust fan on the roof during cleaning or maintenance.
It’s the Law!