Class1 Divison 1

[ccha9219]

I have a small spray booth in the back of an enclosed room that measures 10'x30' with a roll up door at one end.
The spray booth itself is no bigger than a typical computer desk, set in the corner at the back of the room. there is a explosion proof fan and light on the booth itself. The question is
Is the entire room a spray booth or can I go by the 20/10 around the small booth?

 

[benaround]

Re: Class1 Divison 1

THE WHOLE AREA IS CONSIDERED CLASS 1 DIV. 1 UNTIL SEPERATED BY PARTITION OR OTHER APPROVED MEANS.CHECK OUT 516 IN THE 1999 N.E.C.

 

[ccha9219]

Re: Class1 Divison 1

I have, That's way I'm asking, the vent. system is not interlocked with the spraying equipment, but the "booth" is a UL listed assembly with ventilation and lighting in an enclosed room 30' long. so the class 1 division 1 would be 20' from the booth and 10' above. Or do I go by 516-2-b-2
and treat the whole room as a spray booth?

 

[ryan_618]

Re: Class1 Divison 1

It sounds to me like 516.3(D) applies, makeing the surrounding area an unclassified area. This would only apply, however, if it has no communiacting openings. Is that the case?

 

[benaround]

Re: Class1 Divison 1

IF THIS IS AN OPEN FACED ,CLOSED TOP BOOTH THAT YOU HAVE THEN YOU CAN USE 516-2(B)(2)AND THAT IS A SMALLER AREA.

 

[ccha9219]

Re: Class1 Divison 1

It is an open faced closed top booth, so the lights in the room must be explosion proof
thanks for the input
craig

 

[friebel]

Re: Class1 Divison 1

To: ccha9219
If I were you and wanted to do this job properly the first time this is what I would do.
1. I would draw up a plan view using Article 516.3(A)(2)Closed-Top, Open-Face, and Open-Front Spraying.
You said that your exhaust system is not interlocked with the spray application. This means you would use 516.3(B)(b), which states, Class I, Division 2 location shall extend 10 feet horizontaly and 3 feet vertically from the open front of the booth.
After that distance the area will be classified as a non-hazardous area and you do not need explosion-proof lighting fixtures, or equipment in that area.
2.After you have drawn up this plan with the NEC Articles noted, I would contact the local AHJ inspector and get his approval for your plan.
After his approval, I would wire all equipment up, but I would not pour any seals until the inspector approved your installation. I then would pour the explosion-proof seals and you can be confident that you have a first-class installation.

 

[ccha9219]

Re: Class1 Divison 1

I have wired the "room" from above and outside.
so no seal offs are required inside. I had the contractor cut slots in the wall and install Plexiglass panels in j cannel for lighting, silicon at the seams. So all electrical conections are outside the room except for the fan and light at the booth. Seal tight to a seal off outside the room...explosion proof disco for fan,light switch outside roll up door with dust proof cover...inspector pleased.I'm pleased and so is the customer
thanks all
Craig