# Intrinsically Safe and Explosion Proof



## spec grade (Oct 8, 2009)

Thudpucker said:


> Are these two terms, Intrinsically Safe and Explosion Proof to be considered the same or are there different hazardous atmospheres where explosion proof is required but not Intrinsically Safe? I have people who would like to use a electrical paint pump in a paint booth, the pump unit is not IS rated according to the manufacture. The production folk are saying that it is explosion proof (I' not sure how they know that), and asking me to install explosion proof conduit and outlets. I have responded by saying that an explosion proof outlet is not explosion proof if someone unplugs the unit in a hazardous atmosphere condition. Anyway, if there is someone who is familiar with the NEC and perhaps the NFC concerning paint booths, perhaps they would be willing to help.
> Thanks
> Thud


I.S. and xp are different wiring methods for classified areas. I.S.is mostly used in controls switches,valves etc.You have to install a barrier in the safe area and then run your wiring into the haz.location. X.P. is rigid or Imc threaded pipe and XP fittings.Check art.516 for spray booths and art.500 for haz.locations.XP recpts. are designed to break contact while still protected inside the outlet.


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## erics37 (May 7, 2009)

Intrinsically safe means that the circuit won't carry enough energy (especially in arcing caused by switching actions,etc.) to ignite any vapors. Usually you run these sort of circuits through an I.S. barrier of some sort.

Explosion proof refers to the wiring methods, enclosures, devices, etc. that you install in a hazardous location.


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## nolabama (Oct 3, 2007)

think of it this way - explosion proof is the wiring method that you use, and I.S. is the description of the way its fed - control voltage is really really low and no current to speak of , for some reason 1.7 milivolts comes to mind (after reading that white paper that voltage reference is crap) - check out oil production platform white pages for good reads on I.S stuff

good read http://www.pepperl-fuchs.no/DART-White Paper_fieldbus.pdf


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## Thudpucker (Dec 22, 2011)

*IS and XP*

Thanks for the help, sometimes it's hard to get my mind around it all, on one day it's plugged toilets, the next daya problem with the welding robots, or the men in the office who are too hot, and the ladies too cold. I especially appreciate direction to the references material. 
Thud


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## Thudpucker (Dec 22, 2011)

nolabama said:


> think of it this way - explosion proof is the wiring method that you use, and i.s. Is the description of the way its fed - control voltage is really really low and no current to speak of , for some reason 1.7 milivolts comes to mind (after reading that white paper that voltage reference is crap) - check out oil production platform white pages for good reads on i.s stuff
> 
> good read http://www.pepperl-fuchs.no/dart-white paper_fieldbus.pdf


"everything will work out in the end, if its still a mess, it's not the end"


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