Underground raceway - Gas and Elec

[lakee911]

Good morning,

Recently I came accross a2? PVC conduit being used as an underground raceway for UF (12-2 w/ ground) and soft copper piping (1/2") carrying natural gas. It?s open at both ends and comes through the wall in the basement and turns up through the slab in a detached garage. Seeing as how the 2? PVC isn?t required for the UF, I?m not sure that there is a code violation here. Thoughts?

Thanks,
Jason

 

[jmgreer]

is your concern that they are in the same trench?

 

[lakee911]

Well they're in the same not-required raceway...does that make them in the same trench? I dunno ... trench has been covered up. It doesn't seem right, but I'm not sure why it wouldn't be.

 

[jmgreer]

could the pvc be used to protect the uf cable from physical damage? i am not sure what your concern is.

 

[steve66]

So the UF and the copper tubing are both in the PVC.

I don't know if its a code violation, but I don't like it either.

 

[lakee911]

So the UF and the copper tubing are both in the PVC.

I don't know if its a code violation, but I don't like it either.

Yup. Thanks.

 

[lakee911]

According to NFPA 54 National Fuel Gas Code, it says,

7.1.2.1 Cover Requirements. Underground piping systems shall be installed with a minimum of 12 in. (300 mm) of cover.
(A) The minimum cover shall be increased to 18 in. (460 mm) if external damage to the pipe or tubing from external forces is likely to result.
(B) Where a minimum of 12 in. (300 mm) of cover cannot be provided, the pipe shall be installed in conduit or bridged (shielded).
...
7.1.5 Piping Through Foundation Wall. Underground piping, where installed through the outer foundation or basement wall of a building, shall be encased in a protective sleeve or
protected by an approved device or method. The space between the gas piping and the sleeve and between the sleeve and the wall shall be sealed to prevent entry of gas and water.
...
7.1.6.2 Conduit with Both Ends Terminating Indoors. Where the conduit originates and terminates within the same building, the conduit shall originate and terminate in an accessible
portion of the building and shall not be sealed.
...
7.2.4 Prohibited Locations. Gas piping inside any building shall not be installed in or through a clothes chute, chimney or gas vent, dumbwaiter, elevator shaft, or air duct, other than
combustion air ducts.

I guess all is well.

 

[renosteinke]

The UPC, or plumbing code, has details regarding such sleeves. There are specific code requirements. Has anyone looked?

For quick access to a copy ... well, I think we all know where to go for such bulk resources.

 

[Gregg Harris]

Good morning,

Recently I came accross a2? PVC conduit being used as an underground raceway for UF (12-2 w/ ground) and soft copper piping (1/2") carrying natural gas. It?s open at both ends and comes through the wall in the basement and turns up through the slab in a detached garage. Seeing as how the 2? PVC isn?t required for the UF, I?m not sure that there is a code violation here. Thoughts?

Thanks,
Jason

300.8 Installation of Conductors with Other Systems. Raceways or cable trays containing electrical conductors shall not contain any pipe, tube, or equal for steam, water, air, gas, drainage, or any service other than electrical.

 

[lakee911]

300.8 Installation of Conductors with Other Systems. Raceways or cable trays containing electrical conductors shall not contain any pipe, tube, or equal for steam, water, air, gas, drainage, or any service other than electrical.

That would apply if the conduit is a raceway...

Raceway. An enclosed channel of metal or nonmetallic materials designed expressly for holding wires, cables, or busbars, with additional functions as permitted in this Code. Raceways include, but are not limited to, rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquidtight flexible conduit, flexible metallic tubing, flexible metal conduit, electrical nonmetallic tubing, electrical metallic
tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface raceways, wireways, and busways.

This wasn't designed expressly for holding wires, nor is it required since it's UF cable.

Sometimes I see conduit installed as additional physical protection for NM cable installed in an unfinished area. Is this application of conduit any different?

 

[Gregg Harris]

That would apply if the conduit is a raceway...



This wasn't designed expressly for holding wires, nor is it required since it's UF cable.

Sometimes I see conduit installed as additional physical protection for NM cable installed in an unfinished area. Is this application of conduit any different?

??
Recently I came accross a2? PVC conduit being used as an underground raceway

 

[Cow]

I wouldn't have a problem with it. It's no different then if they shared the same trench, they are simply in a sleeve together.

 

[north star]

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What was the depth of the 2" pvc conduit?.....Sounds as though the
UF cable installer may have taken advantage of an available
underground pipe sleeve to run the cable in, rather than having to
dig a separate trench.

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[mlnk]

This is crazy! No inspector would allow gas and electric in the same conduit, even if you call it a "sleeve". To start with, UG gas and elec must be separated by 12" of soil minimum when in the same trench. Also, see Chap 9, notes , on running cable in conduit.

 

[cowboyjwc]

So the UF and the copper tubing are both in the PVC.

I don't know if its a code violation, but I don't like it either.

I'm kind of with Steve on this one, but I asked around the office and we couldn't come up with anyting that said it was a violation.

And I also don't think that 300.8 comes into play here.

 

[Hv&Lv]

This is crazy! No inspector would allow gas and electric in the same conduit, even if you call it a "sleeve". To start with, UG gas and elec must be separated by 12" of soil minimum when in the same trench.

By which code?

 

[Gregg Harris]

I'm kind of with Steve on this one, but I asked around the office and we couldn't come up with anyting that said it was a violation.

And I also don't think that 300.8 comes into play here.

300.8 Installation of Conductors with Other Systems. Raceways or cable trays containing electrical conductors shall not contain any pipe, tube, or equal for steam, water, air, gas, drainage, or any service other than electrical.

Why would 300.8 not come into play?

The UF contains conductors, the pvc is a raceway by definition, and gas is "other system".

What would the purpose of the separation as defined in 300.8 be for?

Could it be possible to have a direct short between one of the conductors and the copper tubing in the same way as it has happened with CSST?

 

[north star]

= =

Since we do not know which was installed first, the
pvc pipe [ sleeving ] might just be a pipe sleeve
intended for the gas supply pipe only and therefore,
not a true raceway.....If this is the case, IMO,
then the pipe sleeving is compliant and not required
to be separated from other systems [ RE: Article
300.8 ]....Also, if this is the case, where the gas
supply pipe was installed first and the UF 2nd,
who makes the determination of which system
is compliant?.....If the pvc pipe was installed
soley for the purpose of running a wet rated
cable assembly; possibly because of a shallow
install, then the gas supply pipe installation
would be in violation of Art. 300.8.

We need / are requesting more info...

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