sbutler
Member
- Location
- North Charleston, SC
Does anyone know of any specific NEC requirements when dealing with a woodworking shop?
Thanks for any and all responses.
Steve
Thanks for any and all responses.
Steve
NEC and Woodworking Shops
- Thread starter sbutler
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lakee911
Senior Member
- Location
- Columbus, OH
Commercial/industrial or residential?
sbutler
Member
- Location
- North Charleston, SC
Great question. Commercial/industrial.
- Location
- Illinois
- Occupation
- retired electrician
Article 503, and maybe 502.
mgookin
Senior Member
- Location
- Fort Myers, FL
Pay particular attention to explosion prevention & mitigation at your dust collector silo.
kwired
Electron manager
- Location
- NE Nebraska
My guess is you are wondering if you have a hazardous location.
NEC doesn't exactly determine just when you have a hazardous location, but does tell you how to wire it if it is determined you do have a hazardous location. That was real helpful wasn't it? I would say some other NFPA publication but don't know which one would be what you need to be looking at, plus any consideration from someone like a Fire Marshal, insurance company, or others that could be called an AHJ in that area. I would also guess ventilation, cleaning, and other practices come into play to some degree.
NEC doesn't exactly determine just when you have a hazardous location, but does tell you how to wire it if it is determined you do have a hazardous location. That was real helpful wasn't it? I would say some other NFPA publication but don't know which one would be what you need to be looking at, plus any consideration from someone like a Fire Marshal, insurance company, or others that could be called an AHJ in that area. I would also guess ventilation, cleaning, and other practices come into play to some degree.
and, in my experience, getting a answer is often not easy.
Too many times I have see areas that IMO should be a Class II or Class III location but getting some authority or insurance carrier to make that decision is difficult.
kwired
Electron manager
- Location
- NE Nebraska
Just having a lot of dust around doesn't necessarily mean you have an explosion hazard. When that dust is airborne is when it becomes an explosion hazard. I work at a place that dries food grade powdered products. We don't treat any areas as hazardous location, but they are washed down every day when in operation which helps tremendously at keeping the dust from reaching hazardous concentration levels.
A wood working shop that has dust collection system(s) is also likely to not be all that hazardous in general, maybe as mentioned you need to pay closer attention to the dust collection system itself, or even some finish application areas could be class 1 areas as well.
Most sawdust from cutting planing and other similar operations are not going to be explosively combustible, it is sanding operations that create fine dust that needs to be considered the most for creating a hazardous location, the heavy dusts are just combustible material and are not much more of a threat than a bunch of cardboard or newspaper and good housekeeping reduces that threat even more.
A wood working shop that has dust collection system(s) is also likely to not be all that hazardous in general, maybe as mentioned you need to pay closer attention to the dust collection system itself, or even some finish application areas could be class 1 areas as well.
Most sawdust from cutting planing and other similar operations are not going to be explosively combustible, it is sanding operations that create fine dust that needs to be considered the most for creating a hazardous location, the heavy dusts are just combustible material and are not much more of a threat than a bunch of cardboard or newspaper and good housekeeping reduces that threat even more.
construct
Senior Member
- Location
- Branson, Missouri
'kwired' mentioned other NFPA publications. The Fire Code Official is authorized to enforce applicable provisions of the codes and standards listed in table 2204.1 of the International Fire Code. For example: NFPA 69 "Explosion Prevention".
david
Senior Member
- Location
- Pennsylvania
We are not under the 2011 code here but I was reminded that there was a new definition added to article 500 for Combustible dust
kwired
Electron manager
- Location
- NE Nebraska
May have been a definition, but just like other hazardous locations NEC still doesn't specifically classify very many locations. We are mostly limited to specific applications in art 511 - 516 that NEC does classify like fuel dispensing areas, spray application, bulk storage plants... those articles covering those installations define what is classified and at what level fairly well, most other applications where there is hazardous material we need to refer to other codes to get classifications for specific areas/situations, or else assume worst case scenario when assigning a classification if otherwise not known.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Combustible Dust has been defined in NFPA 499 as long as I've been in the business. The NEC Section 500.2 definition was extracted from it. Unless there is a large amount of fine sanding, it is unlikely a woodworking shop would be Class II, especially with good housekeeping practices.
Class III is less concerned with explosions than with flash fires. It still isn't something to be ignored. Again though, good housekeeping will eliminate all or most of the Class III issue.
The OP didn't specify electrical classification concerns; in absence of them, there's no particular wiring issues.
Class III is less concerned with explosions than with flash fires. It still isn't something to be ignored. Again though, good housekeeping will eliminate all or most of the Class III issue.
The OP didn't specify electrical classification concerns; in absence of them, there's no particular wiring issues.
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