Variable Frequency Drive Controls for a Spray Booth Exhaust Fan

Finishers report satisfactory results from controls to slow the spray booth exhaust fan when appropriate. November 24, 2008

I'm getting just a little deaf with the full roar of the booth fan, besides the fact that it may be lifting and moving dust across the room onto my finishing. It seems that if there is at least some positive air movement into the filters and out the building, it's doing its job. Anyone using a speed controller? It would have to be for a 3 phase system. Are they difficult to hook up?

Forum Responses
(Finishing Forum)
From contributor K:
I don't have an answer, but would also be interested (but for 110v, not 3 phase) for much the same reasons. Although I'm using an explosion proof fan, I'm not concerned about (possible) sparking from the reduced speed, as I only shoot H20 finishes.

From contributor H:
You can purchase a variable frequency drive, sometimes called inverter, for about three hundred bucks or less. Would be in the circuit after the magnetic starter.

From contributor J:
They're called variable frequency drives. You can get them from a Col-met distributor near you. For the noise, mount your fan outside of your building. You'll probably need a fan stand and motor cover.

From contributor O:
I installed a VFD on my 3hp 3ph booth fan. I used a TECO FM50 from factorymation. They are rated by HP. The cost of the FM 50 was around $200. It works great and was no trouble to install. Just wire the three hot wires in and the 3 motor wires out. I run it at 60hz when spraying, then turn it down to 30-40hz to keep the fumes moving out. The fan is much quieter when running at the slower speeds.