underground conduit ina Class 1 D2 location
- Thread starter bwyllie
- Start date
- Status
It has always been a big controversy about, is the UG area classified the same as the classified area its under or is it unclassified.It now depends on the answer,,,,,,we always took the more stringent side of the coin saying it was unclassified thereby required poured seals but if our client balked we let him make the call and give us a release of liability document.
I know, not the answer you were looking for I'm sure, but an experience I was familiar with.
dick
I know, not the answer you were looking for I'm sure, but an experience I was familiar with.
dick
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
The principal historic electrical area classification standards (NFPA 497 and API RP 500) has alway treated (although never defined) the underground below Division 2 as unclassified. The problem was a few NFPA TCs held the UG was Division 1 for installations within their Scope. A reasonable case may be made for either position.
In 2005 the last serious holdout for Division 1 underground disappeared. Cf Figure 514.3 in the 2002 and 2005 NECs.
When NFPA 30A TC no longer held the UG is Division 1, it opened the door for the last sentence in 501.15(B)(2) and the revised text of the opening statement and Exception in 501.15(C).
As long as 501.15(B)(2) is the only consideration, a 'seal' is still required, but it doesn't have to be explosionproof or meet any of the other requirements of 501.15(C).
In 2005 the last serious holdout for Division 1 underground disappeared. Cf Figure 514.3 in the 2002 and 2005 NECs.
When NFPA 30A TC no longer held the UG is Division 1, it opened the door for the last sentence in 501.15(B)(2) and the revised text of the opening statement and Exception in 501.15(C).
As long as 501.15(B)(2) is the only consideration, a 'seal' is still required, but it doesn't have to be explosionproof or meet any of the other requirements of 501.15(C).
- Status