Explosionproof motor in a house

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paul32

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Minnesota
I don't have any experience with hazardous locations, and normally would tell a customer I can't do it, but a friend has come to me with this. He has a room, part of a shop in his house, to do staining and the like for woodworking, and will put in a vent fan for the fumes. I wouldn't think anything of it if it were like a bath fan, but somewhere he got a recommendation to get a fan with an explosionproof motor. He'll be using stain, paint, lacquer, polyurethane, and the like, both sprayed and brushed on items in the room. The rest of the room has nothing special for hazardous locations--keyless lamp holders in the ceiling, wall scones, receptacles, and a normal sheetrocked room. My first question: is an explosionproof motor overkill, just right, or should more be done in the room? I don't know how explosive the fumes are, but this doesn't seem different from someone finishing their basement (finishing the woodwork) with normal electrical things around without a problem.

So given he has this fan, a Dayton exhaust fan model 3XK51, is anything special needed in wiring it to maintain its hazardous location rating? I haven't seen it, but he describes a short tube sticking out the side, threaded on the outside, with a couple feet long conductors coming from it with the inside of the tube potted. So is this supposed to have a box attached by a locknut? I doubt it since I don't think there would be another way to secure the box. Does any conduit other than PVC have a female adaptor that could be attached? I was not able to find any information about this fan online.

Thanks in advance to the experts here.
 
paul32 said:
My first question: is an explosionproof motor overkill, just right, or should more be done in the room? I don't know how explosive the fumes are,









Sprayed laquer and spraying laquer thinner through an air brush can be very flammable. Belive me, I learned the hard way. 3rd degree burns .
If the fan is pulling all the fumes out of the room. The rest of the outlets should be fine. But obviously to be code compliant. They to should be arranged in such away that an arc could not ignite a vapor.










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I take it your buddy isnt married, or doesnt plan on staying that way long, LOL.... there is no way I could get away with spray painting on a regular basis in my house:grin:
 
Look at Article 516, or NFPA 33 for more info. The entire interior of a room used for spray application is a classified area (Class I, Division 1). The overspray residue, which is combustible, is also very much a concern.
 
I would be inclined to create some kind of booth that would be class 1 div 1, and remove everything possible in the div 2 area around it.

There is a whole code article on this you might want to review.
 
You have already received several excellent suggestions. But right now this is a design rather than an installation issue and the ?first? question whether this ??is overkill, just right, or should more be done?? cannot be answered because the first step in the overall process (Section 500.4(A)) has been overlooked. If someone is concerned enough to use an explosionproof motor in a residential location, the local enforcement authorities and the homeowner?s insurer are both very likely to want to know about it.

Sgunsel?s recommendation to review NFPA 33 is essential. There are very likely issues beyond electrical to consider. Perhaps you don?t feel qualified. The local AHJ may not be either; but there may be other local building codes that prohibit or restrict the operation in the first place. The homeowner?s insurer is the overall best bet to have a person qualified to evaluate the processes and determine the limits of electrical area classification.

Assuming there are ultimately no legal restrictions, then petersonra?s suggestion sounds solid.

Until you return saying a qualified entity has created the proper electrical area classification documentation, I would not give you any recommendations on how to install the motor and I suggest no one else do it either. Consider this an anti-DIY notice from the designer?s perspective.
 
.....and I always thought that local zoning ordinances against running a business in a residential neighborhood were only to guard against hair salons and massage parlors.

This could go really bad for him. I picture the hazmat team showing up when vapor odor complaints come in. As they say NIMBY. Walk away from this job.

You sure it's paints and thinners and not solvents and such for for cooking meth?
 
I think you have a bunch of good advice listed above. Around here the environmental portion of the ahj has a lot to say about paint emissions too, and that is another thing that could go over poorly for your friend if he isn't careful (depending on the area).
 
bobgorno said:
.....and I always thought that local zoning ordinances against running a business in a residential neighborhood were only to guard against hair salons and massage parlors.

This could go really bad for him. I picture the hazmat team showing up when vapor odor complaints come in. As they say NIMBY. Walk away from this job.

You sure it's paints and thinners and not solvents and such for for cooking meth?
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Hazmat, EPA, POLICE, FIRE DEPT., ATTORNEYS, are just a few of the new friends you will make when this goes bad. Very few chemicals more flammable than laquer thinner.
 
Incidentally, there are commerically available paint booths you can buy that are already set up for this kind of situation. people who want to paint stuff can buy them and just plop them down. As I understand it there are generally two versions. one that goes inside a building and one that is desinged for outdoor use.

We have one that is designed for indoor use. It came with some basic instructions on what was allowed to be in the immediate vicinity of the thing. Its nothing real special. But, someone sat down and figured it out up front.
 
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