Is there an equivalent Standard in the US for the application of an Explosive Atmosphere. Installations that spring to mind are: Gas Stations, Spray Paint Booths, LPG Filling Stations. Here NZS 2380.1 covers most things, but they are called Hazardous Areas here. We have EX ratings on all HA gear. How is gear rated in the US?.
Basically, the NEC divides Hazardous Atmospheres into the following (courtesy of the gelightingsystems.com website, since I don't have my Code book handy):
CLASS I locations are those in which flammable Gases or Vapors are ormay be present in the air in quantities sufficient to produce explosive orignitable mixtures.
CLASS II locations are those that are hazardous because of the presence of Combustible Dust.
CLASS III locations are those that are hazardous because of the presence of easily ignitable Fibers or Filings, but in which such fibers or filings are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures
Each “CLASS” is further defined as either Division 1 or Division 2.
DIVISION 1 is an environment that is "Normally Hazardous".
DIVISION 2 is an environment that is "Not Normally Hazardous".
Mike if you have a NEC book look in chapter 5 Hazardous locations. read carefully, it can be confusing and is something of a specalized area. I have seen and heard a lot of sometimes heated discussion about what is needed and where especally when some one is trying to save money. The equipment for hazardous areas can be very very expensive.
Re: Explosive Atmospheres#149954 06/18/0405:32 AM06/18/0405:32 AM
Ed, Doug, Thanks for your responses. Hazardous Area work is something that I try to keep right away from. I have repaired the odd pump in the Fuel pumps here and that was as close as I wanted to get to that kind of thing. I am the Maintenance Electrician, at a local Flour Mill and we have been changing over the last few years, all of the motors to Non-Sparking types (ExN), some of them were Slip-ring types for speed control, but Micro-drives put that fire out!. Last guy didn't have a clue!.
Mike If you look in the NEC that area would fall into the class 2 chapters. I have done enough grain,and dusty area to get my fill of these areas. You need a lot of care to keep the dust out of the equipment. Good explosion proof equipment is expensive but where needed will save lives and property. Unfourtunatly I have seen the result of grain and suger dust explosions, no different for TNT for results. Some of those were fatals to employees. Take care and be safe.