Redsy, are you sure the exhaust fan is listed for use in a commercial kitchen? I do not recall a listed exhaust fan with a Sleeve leading to the exhaust duct. The listed up-blast fans I have seen have some kind sleeve/access point from the outside of the fan, leading to the motor. There should be a label, "This port for wiring access". There is usually a large port leading to the motor housing. That port is for cooling air to enter into the housing. There may be a label "This port for cooling air and is not to be used for wire entry".When you wire the fan, use water-tite or better, water-proof connections and conduit. Make sure there is enough wiring so the fan can be removed for service.
Wiring should not be run in the duct or chase. I have seen wiring run in the duct, a screwdriver used to poke a hole in the duct and the wire shoved through the jagged hole. If wiring is run in the chase, is it rated for the temperature? What happens if the wire makes contact with the outside of the duct? How are you going to seal the fire rated wall you just comprimised? If I see something like that on a job, I will contact the GC, and inspectors to voice my concerns. I will also make a note on my fire suppression system report.
Fireguy
