class 1, division 2, group d question

[red_dog527]

I'm building a methane gas plant at a landfill and there is a compressor room with the class 1, div 2, group d rating. There is a gas skid in the room that has imc conduit ran on it with no xp conduit bodies. This came from the factory this way. Also the control box on the skid and some devices are not xp either. Is this legal? I was sent seal offs and xp switches, and recepts and lights for this room, but was sent cast iron tees for the conduit runs in the ceiling. I don't think this is right, but if they are getting away with it on the gas skid, it makes me wonder. Any explanations would be appreciated. Thanks.

 

[rbalex]

In general, enclosures in Class I, Division 2 are not required to be explosionproof. See [2005] 501.10(B)(4). I might have some concern about the control box, but I don?t know what is actually in it.
My initial concern would be the classification of the compressor room in the first place. Again though, I don?t know the full design so I can?t make any definite comments.


Edit: Corrected the reference in bold

 

[red_dog527]

I can try to explain the room. The room is roughly 25ft. by 25ft. The room is all block walls. Methane gas from the landfill is piped into this room into this gas skid that basically sends the gas to one of four CAT generators that in turn produce electricity that is sold back to the power company. The room with the CAT engine is spect for no XP fittings or anything. Emt in the ceiling and on the walls, but any conduits going into this gas room need seal-offs. As I stated I have xp lights, recepts, and switches. I'm just curious as to why this skid has nothing of the sort on it, as I think it totally defeats the purpose of what they are trying to do. This is just eating at me and I can't get a justified answer from anyone.

 

[bobgorno]

NFPA 37 does not require an engine room to be classified solely because of its own fuel supply, lube oil, or hydraulic fuel. The engine skid could fall under this standard.

A compressor that moves methane gas, and has a power supply of gas is probably required to be classified. Engine should have spark protected ignition systems and other electrtical upgrades if that is the case.

If the engine skid is placed in a room with a gas treating skid, the gas skid might require classification.

Hard to tell without knowing the whole process. You can't get an answer from people at the site because they probably are not sure themselves. I call this the bunny camouflage. If they sit quiet and still, you won't see them and finaly you'll just go away.

Might try getting a copy of AGA XFO277.

 

[rbalex]

From your description, I believe we are actually discussing two rooms, the gas collection room and the generator room. Bob Gorno?s comment about NFPA 37 definitely applies to the generator room. The gas collection room is a different story. (Side note: AGA XFO277 is not an ANSI document and probably does not apply to your installation although it has some good application material)

Assuming the gas collection room is properly classified as Division 2 and there are no arcing, sparking or heat producing (ASH) elements in the control panel, the skid sounds like it is properly constructed. A minor exception may be that there are indeed ASH elements in the control panel but they are themselves suitable for Division 2, such as a hermetically sealed relay.

As I stated in my first response, there is no general need for explosionproof enclosures in Division 2. For the room?s general wiring, explosionproof receptacles and switches would generally be required. The luminares do not necessarily need to be explosionproof, but they would need to be rated for Division 2.

 

[natfuelbill]

What is a "Engine should have spark protected ignition system"?

Do you have a link of this kind of product?

 

[bobgorno]

Bill,

See attached for examples. Altronic and Waukesha are two that make them. I don't think you will find them with other than CSA approval for Div. 2. I don't think the CSA approval is the new CSA North America (CSA approvals covering US and Canada usually has a US and a C next to logo). Use is subject to AHJ or owners risk, still better than no approval. CSA is one of the 17 or so NRTL's recognized by OSHA.

http://www.altronicinc.com/ignition.htm

I tried attaching some .pdfs. If they don't stick, search their site for: syscertification.pdf and safetleadsp.pdf

Bob G.