Speed control for 240v Spray booth exhaust fan

[AdamElectric]

Hey guys!

Had a customer contact me the other day and asked if i could put in a speed control as well as a timer for his 240v spray booth exhaust fan. My question is...Is this legal? And has anyone done this sort of thing before? I don't have experience with this as i am more of a residential guy. Looking for suggestions!

Thanks!!

 

[GoldDigger]

Hey guys!

Had a customer contact me the other day and asked if i could put in a speed control as well as a timer for his 240v spray booth exhaust fan. My question is...Is this legal? And has anyone done this sort of thing before? I don't have experience with this as i am more of a residential guy. Looking for suggestions!

Thanks!!

A lot depends on where he wants to put the control.
And whether it could be turned down far enough that the ventilation does not meet statutory minimums.

 

[ActionDave]

Hey guys!

Had a customer contact me the other day and asked if i could put in a speed control as well as a timer for his 240v spray booth exhaust fan. My question is...Is this legal? And has anyone done this sort of thing before? I don't have experience with this as i am more of a residential guy. Looking for suggestions!

Thanks!!

What kind of motor? If it's single phase it's likely not possible. Even if it is, like Goldy says, it may not be advisable.

 

[Jraef]

It may be possible electrically, depending on the motor (3ph or 1ph, then if 1ph, what kind of motor is it). But it's tricky from a regulatory standpoint as the others have pointed out. Currently, NFPA 33 states that the air volume exchange is required to dilute solvent concentration below 25% of lower flammable limit (lfm). None of that is electrical in nature, but if you facilitate it for him, you may find yourself in trouble if something happens. I used to do paint and blast booth controls, it's a tricky business and I got out because people kept expecting me to be the expert on air flow, and I am not. I just wanted to wire the parts in a box.