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#80448 - 04/16/02 06:34 AM Class I Div 2 Panel location
mebner Offline
Junior Member

Registered: 04/16/02
Posts: 1
Loc: Chippewa Falls, WI USA
Would anyone know where I can find information on the location of a control panel enclosure for a class I Div 2 area. I know there is some blurb about an 18" rule, where anything located above 18" is considered a non-classified area if the vapors are heavier than air. I'd like to keep the panel on a the piece of equipment we're that's there without having to locate it in a non-classified area. Any help would be great. Mike

2014 / 2011 NEC & Related Books and Study Guides
#80449 - 04/16/02 07:39 AM Re: Class I Div 2 Panel location
resqcapt19 Offline

Registered: 11/10/00
Posts: 2209
Loc: IL
We need a lot more information as to the type of installation. The only 18" rules that I can think of are for gas stations and garages. These rules do not apply in other occupancies.

#80450 - 04/16/02 09:01 AM Re: Class I Div 2 Panel location
Bob Offline

Registered: 02/05/02
Posts: 182
Loc: Mobile, AL, USA
You may be thinking of the 18 inch maximum run of conduit regarding the sealing requirement. If the panel is rated for Div 1 Class 2 you should be able to install it anywhere. If not rated you can not install it
in the classified area.

#80451 - 04/17/02 08:29 PM Re: Class I Div 2 Panel location
sparks55 Offline

Registered: 03/31/02
Posts: 11
Loc: Iowa, USA
The boundary between classified locations is determined by the AHJ. I worked at a P&G plant that uses alcohol in their products. The tanks used for storing the finished product were located in an open area and the area within 10' of the tanks was Class I Div 2. The boundary is an imaginary line and not a wall, which P&G documents with drawings.

If you locate the control panel in a classified area, it must be rated for that location. Check with the AHJ to determine the boundary.

#80452 - 04/18/02 07:12 AM Re: Class I Div 2 Panel location
Cindy Offline

Registered: 06/23/01
Posts: 196
Loc: PDX, OR, US
i think your answers might be in 501.1 thru 501.6

501.1 says if you want to use equipment in the classified area it has to be LISTED for that area...
Equipment listed and marked in accordance with 505.9(C)(2) for use in Class I, Zone 0, 1, or 2 locations shall be permitted in Class I, Division 2 locations for the same gas and with a suitable temperature class.
Exception: As modified by this article.

501.5 says you need sealing fittings...
501.5(B)(2) Class I, Division 2 Boundary. In each conduit run passing from a Class I, Division 2 location into an unclassified location. The sealing fitting shall be permitted on either side of the boundary of such location within 3.05 m (10 ft) of the boundary and shall be designed and installed so as to minimize the amount of gas or vapor within the Division 2 portion of the conduit from being communicated to the conduit beyond the seal.

there are some other things required in that section also

do you have the arlington explosionproof catalog? not sure what its called, maybe not even arlington, i'll get it from my rig and post the info, its from the 99 code but has code applications and materials, a good book to have around


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