514.8 Question

[augie47]

514.8 Exception allows RNC where buried under 2 ft of cover (provided rigid is used at the ends)....
When the RNC run from the dispensers is routed under the building slab, si the 24" cover still required ?

 

[raider1]

IMHO Yes.

Chris

 

[rbalex]

I agree with Chris.

Arts 510 - 516 aren't entirely in the control of CMP14. A large amount is extracted from other NFPA standards.

The Tech committee that controls NFPA 30A has historically considered the location below a classified location to be Division 1 due to spills and leakage. That is not the common point of view with CMP14 and the NFPA 497 or API-RP500 Tech committees. (Compare the current Figure 514.3 with earlier versions.)

The NFPA 30A Tech committee was reconstituted a few cycles ago; some of constraints have been relaxed and some retained. In general, there is a concern that "leakage" can go both ways and 24" of covreage is necessary in all cases. Compare the 514.8 with 501.10(A)(1) along with its Exception that includes an internal exception for 514.8.

 

[augie47]

Thanks

 

[rbalex]

... (Compare the current Figure 514.3 with earlier versions.)...

More specifically compare Figure 514.3 in 2005 or ealier. Extracted material is also better identified.

 

[augie47]

Interesting side note: Despite the Forum opinions, my supervisors decided the installation was not a violation. At a IAEI/NFPA seminar this weekend, after the subjct was discussed by a NFPA engineer, they changed their ruling to agree that anything less than 24" is a violation.

 

[rbalex]

For curiosity?s sake; how much reduced cover were they prepared to permit? And what was the basis?