Replies

1. 
   northhouguy | Dec 22, 2009 10:09am | #1

   No, attic fan blowers are generally not explosion proof.

   Put the fan outside the spray booth and blow air IN, not OUT. make sure your air intake is far enough from the spray booth so that only clean air is sucked into the booth. Exhaust the dirty air outside, far from the intake.

   Keep in mind that any lights, switches, outlets, etc. in the spray booth will have to be suitable for the correct hazardous location.

   Also, any electrical devices outside the booth, but located within 3 ft. of openings in the the walls of the booth, (doors, windows, etc.), will have to be suitable for the hazardous location.

   Article 516 of ther National Electrical Code covers spray booths. It's complicated, so I recommend consulting a qualified electricain with knowledge of the code. Better to be safe than sorry.

2. 
   Don01 | Dec 22, 2009 10:18am | #2

   Brian,

   If you can see any of the internals of the motor it is likely not explosion proof. The name plate should carry a NEMA rating of Class I or II and then a Div. number.

   Best to take the motor name plate details to a repair shop or try an internet search on the manufacturer and see what they say.

   Don

3. 
   WillGeorge | Dec 22, 2009 10:26am | #3

   No expert on the subject but I would doubt it. For fire safety the entire electrical supply such as fittings, switches etc. must also be rated by National Fire Protection Association (NFPA).

   As I recall, when servicing some equiment, the motors had a NFPA label. They were completely sealed and the power connections were all sealed as well as lighting fixtures.

   From my experience, even these motors can catch fire but the fire/explosion is held within the housing. These were 240/480 volt, 2 and 3 phase... 10 to over 100 hp motors. Also some large hp DC motors with electronic controllers were rated and had a label as I recall. Many areas required a licensed electrican check my work before power could be restored to the machine. I 'think' I remember in California the electrican had to be there during the complete install/replacement.

   For true protection everything within the room must be rated for explosion protection.

   But then again, many (I assume) do it all the time. Even common spray cans of some solvents will go up in flame under the right conditions.

   Maybe somebody that sprays will chime in and give advice.

4. 
   Westchester | Dec 22, 2009 12:15pm | #4

   Hello

   I spray lacquer - my fan came with an explosion proof motor. The electrician ran the wire through pipe and sealed the connections with epoxy. Of course other causes must be guarded against - i.e. anything that can cause a spark. My suggestion following taking all precautions the local fire dept recommends - is limit your spraying so that the room never gets to be a cloud of finish. I spray tops, then sides, then drawers with time between waiting for the room to clear.

   Regards,

   SA