I have always been taught that article 500-517 of the NEC provides installation requirments for hazardous locations but the actual classification is left to the AHJ or insurance carrier. Since the NEC is not a design specification (NEC 90-1(C)) but rather provides requirements for the installation of electrical equipment in a hazzardous locations it cannot be used for determining the actual area classification. Comments?
Hazardous locations
- Thread starter bh
- Start date
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rick hart
Senior Member
- Location
- Dallas Texas
Re: Hazardous locations
So......
If an electrician goes to a place where the AHJ is the installing electrician, it would be ok to wire a gasoline pump with NM? There is a difference between design and installation.
I was taught as a Journeyman that even with stamped drawings in hand, if the installation conflicts with the NEC, it was my responsibility to point that out to the engineer. I have never had an engineer claim "Engineering Supervision" was the reason for the oversight and they saw it my- the NEC's- way.
On the other side, I have had AHJ- safety officers- say that oxygen bottle storage was a classified location.
After asking them if they considered O2 a flammable gas, dust or metal they came off the need for seal offs and explosion proof fixtures.
I guess my point is to know the code and share the knowledge.
So......
If an electrician goes to a place where the AHJ is the installing electrician, it would be ok to wire a gasoline pump with NM? There is a difference between design and installation.
I was taught as a Journeyman that even with stamped drawings in hand, if the installation conflicts with the NEC, it was my responsibility to point that out to the engineer. I have never had an engineer claim "Engineering Supervision" was the reason for the oversight and they saw it my- the NEC's- way.
On the other side, I have had AHJ- safety officers- say that oxygen bottle storage was a classified location.
After asking them if they considered O2 a flammable gas, dust or metal they came off the need for seal offs and explosion proof fixtures.
I guess my point is to know the code and share the knowledge.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Re: Hazardous locations
Actually, the way this is supposed to work is that someone representing the owner classifies the area. This might typically be an engineer. Normally the area classification is documented on drawings by showing what areas are classified and what the classification is (although I have seen it done other ways).
The AHJ would either go along with this determination or not. It is rare that the AHJ would make this kind of design decision.
Actually, the way this is supposed to work is that someone representing the owner classifies the area. This might typically be an engineer. Normally the area classification is documented on drawings by showing what areas are classified and what the classification is (although I have seen it done other ways).
The AHJ would either go along with this determination or not. It is rare that the AHJ would make this kind of design decision.
friebel
Senior Member
- Location
- Pennsville, N.J.
Re: Hazardous locations
Electrical Hazardous Classifications: I wish to give my ideas and experience on classifying hazardous areas. I worked for the DuPont Company for 45 years, and in that time, gained a great deal of experience in Classifying hazardous Areas.
Our DuPont Standards would dictate, that to classify a hazardous area you must have present at a meeting the following people.
1. The manager of the site that is to be classified.
3. A chemical engineer or chemist, that is familiar with the chemicals that we will be dealing with.
4. An electrical engineer or an electrical person familiar with the NEC Articles for classifying.
5. After all this information is compiled, it is put onto a print for documentation. The area that is classified, and the boundaries that are classified.
Electrical Hazardous Classifications: I wish to give my ideas and experience on classifying hazardous areas. I worked for the DuPont Company for 45 years, and in that time, gained a great deal of experience in Classifying hazardous Areas.
Our DuPont Standards would dictate, that to classify a hazardous area you must have present at a meeting the following people.
1. The manager of the site that is to be classified.
3. A chemical engineer or chemist, that is familiar with the chemicals that we will be dealing with.
4. An electrical engineer or an electrical person familiar with the NEC Articles for classifying.
5. After all this information is compiled, it is put onto a print for documentation. The area that is classified, and the boundaries that are classified.
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