Classified areas around motor fuel dispensing facilities Article 514

[briankrogers]

I am dealing with installing a mixed fuel dispensing facility (LNG, CNG, gasoline and diesel) and there is an ongoing debate about area classification around the dispensers. According to tables 514.3(B)(1) and 514.3(B)(2) it talks about the classified areas within the dispensers and the area classification around them. This question is this: Does the area classification also extend to the hose? In all pictures and references, it refers to the dispenser as a fixed entity. All dispensers have a house (can be up to 18 feet). If I extend the hose in a radius of the dispenser, is that where the classified area is to rated? Does the dispenser in essence become a device with an 18 foot radius or is it a (typical) rectangular device and it is the mechanical dispenser itself that we use as the guidelines for the two aforementioned tables and not the hose.

 

[north star]

+ = +

briankrogers,

1st, ...Welcome to the Mike Holt Forum!

2nd, ...according to Table 514.3(B)(1) [ `08 NEC ], ...in
the area concerning Dispensing Device: The space up to
18" horizontally in all directions and extending to grade,
from the dispenser enclosure, and within 20' horizontally
from the outside edge of the dispenser is considered a
Class 1, Division 2 location.

FWIW, there is a diagram / figure in the `08 NEC
Handbook, ...Figure 514.3.

= + =

 

[kwired]

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briankrogers,

1st, ...Welcome to the Mike Holt Forum!

2nd, ...according to Table 514.3(B)(1) [ `08 NEC ], ...in
the area concerning Dispensing Device: The space up to
18" horizontally in all directions and extending to grade,
from the dispenser enclosure, and within 20' horizontally
from the outside edge of the dispenser is considered a
Class 1, Division 2 location.

FWIW, there is a diagram / figure in the `08 NEC
Handbook, ...Figure 514.3.

= + =

But what if you had a hose that extends beyond that 20'? I think what the op is asking is whether or not the hose and where it can reach is considered part of the dispenser. Seems pretty logical that it could be.

 

[rbalex]

Article 514 assumes the overall installation conforms with NFPA 30A, Code for Motor Fuel Dispensing Facilities and Repair Garages, from which it is largely extracted. [See the 514 Title FPN and 514.1 FPN]

Generally, electrical area classification is indeed defined relative to the dispenser unit itself without consideration of the hose. Except at the terminus, the hose itself is considered to be "closed piping" and does not require classification around it. Modern hose delivery systems, with vapor recovery at the termius and auto shut-off, is not considered a source either. Even in the "old days", when those features were not common, the terminus was not considered a source "by experience".