class1 div 2
- Thread starter 101010
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kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
You need to determine exactly where the classified boundary is. Outside the door likely is outside the classified area but not always.
Other things that may effect where the boundary actually is located is type of hazardous material, ventilation, rating of door, rating of wall.
Commercial repair garage
Commercial repair garage
I have a similar question. The code references the class 1 area in a commercial garage as being 18" above the "floor space." Does the wiring within finished walls fall under this designation? Basically, can the wiring concealed within the walls be installed below 18" as long as the receptacles and other devices are above 18"?
Commercial repair garage
I have a similar question. The code references the class 1 area in a commercial garage as being 18" above the "floor space." Does the wiring within finished walls fall under this designation? Basically, can the wiring concealed within the walls be installed below 18" as long as the receptacles and other devices are above 18"?
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
The primary concern, at the moment, is how the classification was determined in the first place. Without more information, I always raise an eyebrow when a room is only classified Class I, Division 2. If it wasn?t based on Articles 511 to 516 or a specific NFPA Standard, such as NFPA 820, it is much more likely to be unclassified depending on how the Class I materials are used or Division 1 depending on ventilation. If it did need to be Class I, very few rooms are adequately ventilated to drop from Division 1 to Division 2. Although there are a few other protection techniques in Section 500.7 that may permit treating it as a Division 2 location, they are rare applications.
Rating of the walls/doors is a bit less of a consideration; the primary concern for them is whether they are penetrated or not. Porosity is not generally a concern; a good coat of paint will solve that.
Find out what the basis of the classification is in the first place, THEN you can determine the boundaries.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Very much like the OP you need to determine how the boundaries were/are fixed. Basically, "You gotta draw the line somewhere." As long as the wiring does not cross the boundary (the line), then what you described (what I underlined) is fine.
weressl
Esteemed Member
I would add that without negative pressurization of the room there would be a Cl. I, Div 2 area at the outside of the door. It counts a a penetration of the solid barrier, or wall. (I have added extensive ventillation to a large, indoor, existing process building to make sure that it is Div. 2 and classified an another one as Div. 1 where no adequate ventilation existed, nor could it be added.)
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