Gas Station Rebuild

[sgunsel]

The area where the wiring currently ends will become parking and/or sidewalk, adjacent to the new building.

Article 514 states that any underground wiring passing under or through the Class I, Div 1 or 2 areas is to be considered in a Class I Div 1 area at least until it emerges above grade, where it must be sealed.

BTW, significant spillage during vehicle fueling is common, even with the newest dispensers. Some are much worse than others. All of the spillage does not evaporate, as concrete is fairly porous. Although an epoxy sealant would probably help, it could create static electricity issues, not good when fueling with gasoline.

 

[stickelec]

Article 514 states that any underground wiring passing under or through the Class I, Div 1 or 2 areas is to be considered in a Class I Div 1 area at least until it emerges above grade, where it must be sealed.

I'm not trying to be argumentative, I just can't find it in Article 514. In fact 514.8 Exception 2 allows RNC underground...not typically what I would expect to see in a Div.1 area (at least as applied to other C1 applications).

 

[DAWGS]

I have worked a few projects similair, we converted a few of the old Mobile stations to the new On The Run Mobils (Blimpie). Builing was demoed and original pumps and islands stayed. We busted all the chico in most runs and busted off fittings in the ones we couldn't get chico out. All conduits were cut by digging up section cutting and unthreading to last coupling. Pulled out wires and rerouted to new area. Of course these stations were shut down all during construction. Sounds like yours wants to stay open during construction.

 

[rbalex]

...I'm probably missing it but I can't see where 514 classifies the underground, ...

The 2002 NEC for Section 514.8 says:

514.8 Underground Wiring.

Underground wiring shall be nstalled in threaded rigid metal conduit or threaded steel ntermediate metal conduit. Any portion of electrical wiring or equipment that is below the surface of a Class I, Division 1, or a Class I, Division 2 location [as classified in Table 514.3(B)(1) and Table 514.3(B)(2)] shall be considered to be in a Class I, Division 1, location that shall extend at least to the point of emergence above grade.​

[rbalex Note: Underline added.]

 

[rbalex]

Section 501.10(A)(1)(a) Exception also permits RNC underground. It is the ?general? exception and recognizes additional conditions in 514.8, Exception No. 2 and 515.8(A) that permit omitting the concrete encasement.

?Underground? has always been something of a special case. Some experts asserted that it is always unclassified others have claimed it is should always be Division 1 when it is beneath a Classified location. A few have endorsed that it be classified the same as the area above. The general concern is that however you classify the underground it has significant impact on boundary sealing issues.

The trend is toward treating underground as unclassified, but that begs the question why 501.10(A)(1)(a) Exception exists at all; i.e., if it is unclassified why do you even need an Exception.

To my knowledge, there is still no clear consensus. Personally I tend to endorse the ?trend,? but I still recognize there are some persuasive alternate opinions.

​

 

[rbalex]

Spillage from the dispensers is still the concern from the electrical area classification viewpoint of the NFPA Technical Committees.

Apart from various environmental laws (which still vary by jurisdiction) NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages is the primary national consensus Standard for “Gas Stations.” The Standard addresses all the construction requirements you mentioned; nevertheless, the NFPA 30A TC still believes spillage is of sufficient concern to warrant the underground requirements listed in NEC Section 514.8.

 

[wallyworld]

This has got me reviewing 501 and 514 again so thats a good thing:smile:

 

[David Channell]

Gas Station changes

Gas Station changes

It sounds like someone who is untrained on class one div. one and two is trying to do work on a gas station. If you want to end up in lots of trouble because you caused a big fire or worse just jump in and see what happens.

 

[petersonra]

Spillage from the dispensers is still the concern from the electrical area classification viewpoint of the NFPA Technical Committees.

Apart from various environmental laws (which still vary by jurisdiction) NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages is the primary national consensus Standard for ?Gas Stations.? The Standard addresses all the construction requirements you mentioned; nevertheless, the NFPA 30A TC still believes spillage is of sufficient concern to warrant the underground requirements listed in NEC Section 514.8.

where would the oxygen come from to ignite a flame in the dirt underground?

 

[petersonra]

where would the oxygen come from to ignite a flame in the dirt underground?

I actually meant to ask where would the oxygen come from to sustain a flame in the dirt underground.