Articles 514 and 515

[Dale001289]

A few points that need ‘splainin’ - (at least for my sake ):
You’d think this Article is all about gasoline filling stations for vehicles - BUT you’d be wrong, it includes pumps and tanks for Tank Farms…Huh? Or, 514.3(B)(2) - it includes CNG, LNG and LPG – As far as I know, no one makes a car that runs on LNG.

Or, Figure 514.3: the 2002 Code describes earth (below grade) as Division 1 – the 2005 Code changed it to non-hazardous (Figure 514.3)… but 515.9 states buried cables and raceways "shall be considered to be within a Class I, Division 1 or Zone 1 location"

Why can they make up their minds? Which is correct, which is safest?

 

[dkidd]

But there are other vehicles that do.

http://www.lngvehiclefuel.com/

 

[Dale001289]

But there are other vehicles that do.

http://www.lngvehiclefuel.com/

Well I be dam*ed, thanks dkidd

 

[rbalex]

Three different Technical Committees (TCs) are involved with these two Articles: NEC CMP 14, the NFPA 30 TC (Art 515) and the NFPA 30A TC (Art 514). [See the Informational Notes after the titles of the two Articles.] They don't always agree with each other. CMP 14 has very little control of the two Articles' content. The NFPA has basically forced the will of the other two TCs on the NEC. At one time, the TC that controlled NFPA 30 covered both Articles. It was in 2005 that the NFPA 30A TC was formed.

Part of the Exception in Section 501.10(A)(1)(a) hoped to reduce, but it didn't quite eliminate, some conflicts between the Articles and Section 501.10(A)(1)(a) itself. Typically, below grade is considered unclassified. The TC's for NFPA 30 doesn't agree. The "new" NFPA 30A TC has come around a bit.

Note Section 515.9 doesn't actually say below grade is classified just that it will be treated that way.​

The eternal word smithing of the NEC has reintroduced some conflicts. It can take up to 2-3 Code cycles to clear it all up. Sometimes it never completely happens. In this particular case, resolution has to go up beyond the NEC Technical Coordinating Committee (TCC) to the NFPA Standards Council.

 

[Dale001289]

Three different Technical Committees (TCs) are involved with these two Articles: NEC CMP 14, the NFPA 30 TC (Art 515) and the NFPA 30A TC (Art 514). [See the Informational Notes after the titles of the two Articles.] They don't always agree with each other. CMP 14 has very little control of the two Articles' content. The NFPA has basically forced the will of the other two TCs on the NEC. At one time, the TC that controlled NFPA 30 covered both Articles. It was in 2005 that the NFPA 30A TC was formed.

Part of the Exception in Section 501.10(A)(1)(a) hoped to reduce, but it didn't quite eliminate, some conflicts between the Articles and Section 501.10(A)(1)(a) itself. Typically, below grade is considered unclassified. The TC's for NFPA 30 doesn't agree. The "new" NFPA 30A TC has come around a bit.

Note Section 515.9 doesn't actually say below grade is classified just that it will be treated that way.​

The eternal word smithing of the NEC has reintroduced some conflicts. It can take up to 2-3 Code cycles to clear it all up. Sometimes it never completely happens. In this particular case, resolution has to go up beyond the NEC Technical Coordinating Committee (TCC) to the NFPA Standards Council.

Bob, thanks I greatly appreciate the time for this excellent feedback! While I was working Fluor Global Group at the Koch Refinery in MN (now Flint Hills) a spill occurred and the ground became saturated with fuel oil. I don't remember exactly how deeply the oil penetrated, but I want to say it was over 12". From a purely personal standpoint, I've always preferred the first 24 inches of earth below grade be classified as Division 1. But of course, ultimately we must abide but what the Code says.

 

[don_resqcapt19]

Bob, thanks I greatly appreciate the time for this excellent feedback! While I was working Fluor Global Group at the Koch Refinery in MN (now Flint Hills) a spill occurred and the ground became saturated with fuel oil. I don't remember exactly how deeply the oil penetrated, but I want to say it was over 12". From a purely personal standpoint, I've always preferred the first 24 inches of earth below grade be classified as Division 1. But of course, ultimately we must abide but what the Code says.

So you expect that if you took a shovel full of dirt from that area, you could set the dirt on fire?

 

[Dale001289]

So you expect that if you took a shovel full of dirt from that area, you could set the dirt on fire?

No, but if underground cable faulted, or if an above grade fire started....see where I'm going here?

 

[don_resqcapt19]

No, but if underground cable faulted, or if an above grade fire started....see where I'm going here?

No I don't...if there is not enough product in the dirt to let it catch on fire, I don't see an issue. (and if there is, I am sure the EPA would be very interested)

 

[Dale001289]

No I don't...if there is not enough product in the dirt to let it catch on fire, I don't see an issue. (and if there is, I am sure the EPA would be very interested)

They key word in your response is "if" - why would you err on the side of risk?

 

[Dale001289]

No I don't...if there is not enough product in the dirt to let it catch on fire, I don't see an issue. (and if there is, I am sure the EPA would be very interested)

Also, I used the word 'saturated' in my intitial post; wouldn't this indicate a very large quantity was contained within the soil?

 

[rbalex]

Also, I used the word 'saturated' in my intitial post; wouldn't this indicate a very large quantity was contained within the soil?

Normally, I would let Don continue on with this discussion without further comment of my own. However, one of the common reasons given in general practice for leaving the underground unclassified is that, if sufficient fumes or vapors collected in the raceway, they would be too rich to ignite. This would be particularly true if it were flooded.

This is the philosophy adopted by the technical committees for both NFPA 497 and API RP 500.

 

[don_resqcapt19]

They key word in your response is "if" - why would you err on the side of risk?

You already told me that you did not think you could ignite the dirt. I don't see a real risk there.

 

[wallyworld]

Dirt burns when it has enough gasoline in it

 

[GoldDigger]

Dirt burns when it has enough gasoline in it

But only when exposed at the surface, not underground!

 

[Dale001289]

Normally, I would let Don continue on with this discussion without further comment of my own. However, one of the common reasons given in general practice for leaving the underground unclassified is that, if sufficient fumes or vapors collected in the raceway, they would be too rich to ignite. This would be particularly true if it were flooded.

This is the philosophy adopted by the technical committees for both NFPA 497 and API RP 500.

In general, contractors hate explosion-proof conduit seals due to high cost both of materials and labor. Per this thread, it appears we've been doing it correctly here on site. I will yield to the philosophy of committees you've noted but still question the fundamental logic of de-classifying the earth. PVC conduits installed in concrete encased ductbanks eventually become filled with water, even though theoretically this shouldn't happen, its nonetheless reality. If water can enter the duct system, so can gasoline or any other volatile liquid as noted in Article 514.8: "Fuel spilled in the vicinity of gasoline dispensers seeps into the ground and may migrate in the underground electrical conduits"...

Thanks again.

 

[Dale001289]

Dirt burns when it has enough gasoline in it

Yes. Even Article 513.8(B) alludes to underground being considered Class I, Division 1.

 

[Dale001289]

But only when exposed at the surface, not underground!

Correct, the Fire Triangle must include a source of oxygen. However, underground conduits may not be completely devoid of oxygen.

 

[wallyworld]

But only when exposed at the surface, not underground!

You need oxygen to support fire so where is that point?. Obviously on the surface. I've seen many contaminated sites, rarely have I seen fire. As far as gas in ground goes new technology pretty much eliminates this happening.

 

[rbalex]

As I mentioned earlier in this thread, CMP 14 has very little influence on Articles 511 through 516. However, those are the only Articles where Electrical Area Classification can be determined from the NEC itself. Other relevant Standards are listed in Section 500.4(B), primarily in Informational Note No. 2.

If if you believe the underground should be classified as a general condition, you can make a Public Input (PI) to the various NFPA documents, such as NFPA 497 or the NEC itself, in a manner similar to that for regular NEC PIs. For API revisions you would need to contact the Secretary of the Subcommittee on Electrical Equipment (SOEE). I no longer know who that is. Be prepared to substantiate your proposal beyond simply saying you believe it's a good idea. You need to show that failure to do so has historically been demonstrated to cause a problem. That will be extremely difficult. The NFPA will not ignore a PI. For API you may or may not get a documented response.

 

[rbalex]

Dirt burns when it has enough gasoline in it

This is already an EPA violation. Where such soil is broken into and such conditions exist, the hazardous soil must be removed all the way until no such soil remains. The soil must be taken to a special remediation yard for disposal. It is an extremely costly activity. Many gas stations with leaking underground storage tanks have suffered such a fate.