Waiting on the engineering drawings but trying to head off a problem. Paint mix area, Class 1, with an overhead rollup door. The motor and contrils are outside the room itself. Is there normally a "halo" around door openings in Class 1 or is that specific to paint booths, etc.
Doorway Class 1 Div 1
- Thread starter augie47
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- Mission Viejo, CA
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- Professional Electrical Engineer
Mixing alone does not usually introduce a classified location. Then again, "Class 1" only applies to Article 725; paint spray booths are usually Class I
. (Sorry Augie, I had to do it to someone.)No problem.. In this case I'm just the messenger and thats the way it was presented to me
I may continue to put foot in mouth but you are already aware that Hazardous is a weak area for me so...
Generally speaking, other than Art 516, would you expect the area around the door to a classified area to be classified also, or is that too broad a question ?
I may continue to put foot in mouth but you are already aware that Hazardous is a weak area for me so...
Generally speaking, other than Art 516, would you expect the area around the door to a classified area to be classified also, or is that too broad a question ?
IntrinsicSafety
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- Location
- Alberta, Canada
Situations vary a lot, making any generalization hazardous (ha - pun).
Generally speaking, and based solely on NFPA 497 guidance (without a lot of thinking), I would say:
- If there is a Div 1 inside the door, and the door is opened as part of any expected activity (no matter how infrequent), the outside would also be Div 1;
- If there is a Div 1 inside the door, and the door is not opened as part of any expected activity (no matter how infrequent), but can be opened, the outside would be Div 2;
- If there is a Div 2 inside the door, and the door is opened as part of any expected activity (no matter how infrequent), the outside would also be Div 2;
- If there is a Div 2 inside the door, and the door is not opened as part of any expected activity, but can be opened, the outside is still Div 2.
Obviously situations vary a great deal, but a rule of thumb would be a Div 1 hazloc would extend outside the door to a 3'-5' radius in all directions; Div 2 might be up to 15' all directions.
I'm not saying that the paint mixing operation would actually give rise to any hazloc, but if it did, the above would be a reasonable first approximation.
Generally speaking, and based solely on NFPA 497 guidance (without a lot of thinking), I would say:
- If there is a Div 1 inside the door, and the door is opened as part of any expected activity (no matter how infrequent), the outside would also be Div 1;
- If there is a Div 1 inside the door, and the door is not opened as part of any expected activity (no matter how infrequent), but can be opened, the outside would be Div 2;
- If there is a Div 2 inside the door, and the door is opened as part of any expected activity (no matter how infrequent), the outside would also be Div 2;
- If there is a Div 2 inside the door, and the door is not opened as part of any expected activity, but can be opened, the outside is still Div 2.
Obviously situations vary a great deal, but a rule of thumb would be a Div 1 hazloc would extend outside the door to a 3'-5' radius in all directions; Div 2 might be up to 15' all directions.
I'm not saying that the paint mixing operation would actually give rise to any hazloc, but if it did, the above would be a reasonable first approximation.
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