Electric and Gas line in same trench to detached garage

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  #1  
Old 08-07-14, 08:50 PM
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Electric and Gas line in same trench to detached garage

Hello,

I've got a detached 2nd garage about 120' away from the attached garage. There's an existing heater in the attached garage with a 1/2" copper line to it and a natural gas heater 50k btu (existing) - 2psi service to the house. I'd like to T off of that existing heater / copper line and run a 3/4" yellow plast pipe (with risers) to the detached garage.

I've also got a 6/3 w/ ground direct burial wire to run for a 60amp 240v subpanel.

My question is what are the codes regarding burial depth, and minimum separation (vertically or horizontally) between the gas pipe, and the 6/3 power line.

I've also got a 1 1/2" white PVC conduit going out there, but was going to reserve that for the RG-11 coax, MM fiber, and CAT6 network drop. The depth of the white PVC is about 14".

Basic questions:

If I rent a 36" trencher, can I drop the gas line at 36", then back fill 12" of dirt, then drop the electrical?

Thanks for any help or recommendations you can provide!

p.s. this is located in WI St. Croix county Town of Hudson.

Thanks!!!

Mike
 
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Old 08-09-14, 09:18 AM
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The electrical side of things sound good. You need to be sure the top of the 6/3 is at least 24" deep.

I can't speak to the depth of the gas pipe, but teeing off the 1/2" pipe will probably not be code compliant. I'm not great on gas pipe sizing, so you may have to wait for the experts to stop by.
 
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Old 08-09-14, 09:29 AM
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I've also got a 1 1/2" white PVC conduit going out there
I've never seen nor do I believe there is such a thing as a white PVC conduit. Are you sure this isn't PVC plumbing pipe?
 
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Old 08-09-14, 10:16 AM
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FWIK gas line gets buried 12" to code and electric line is 18"
 
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Old 08-09-14, 11:53 AM
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So I've seen two conflicting depths on the electric - can someone please confirm if it's 18" or 24" deep?

Can the electric and gas be in the same trench with 12" vertical dirt separation? or do I need two separate trenches 12" apart horizontally?
 
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Old 08-09-14, 11:56 AM
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Hey Joe, Correct it's white 1 1/2" PVC that's typically used for plumbing. However it also makes for a great conduit!
 
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Old 08-09-14, 12:00 PM
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Thanks Zorfdt,

A guy from my local gas company was here and said the T off of the existing 1/2" copper line would be fine to do since I've got a 2psi head-end. I'd prefer to home run it, but if it's not necessary I guess it's not worth the extra $$$.
 
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Old 08-09-14, 12:11 PM
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T off of the existing 1/2" copper line would be fine to do since I've got a 2psi head-end.
I've got a detached 2nd garage about 120' away from the attached garage. There's an existing heater in the attached garage with a 1/2" copper line to it and a natural gas heater 50k btu (existing) - 2psi service to the house. I'd like to T off of that existing heater / copper line and run a 3/4" yellow plast pipe (with risers) to the detached garage.

Maybe, maybe not... You need to do the actual calculation to determine.. Just a guy saying so is not good enough.

You need to tell us the gas pipe layout with lengths and sizes. And BTU of all appliances if you want us to help with the gas..
 
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Old 08-09-14, 12:37 PM
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Hey Joe, Correct it's white 1 1/2" PVC that's typically used for plumbing. However it also makes for a great conduit!
It won't pass an electrical inspection because plumbing pipe is not U.L. Listed for use as a conduit or wireway.

So I've seen two conflicting depths on the electric - can someone please confirm if it's 18" or 24" deep?
The general rule is 18 inches cover for conduit and 24 inches cover for direct burial cables. There are, however, some variations when encased in concrete or if the feeder is GFCI protected.
 
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Old 08-21-14, 10:51 AM
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That's the reason I got direct burial electrical wire (6/3 w/ ground) - the electrical is not going through the PVC. It will only be used for a 6 strand MM fiber, CAT6, and an RG11 coax (i.e. only low voltage will be fed through the PVC). Are you saying the buried PVC can't be used to feed low voltage?

I was able to confirm 24" for electrical, and 12" minimum for gas.
 
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Old 08-21-14, 10:54 AM
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Well, he actually did do some calculations taking into account the BTU I would need to heat the space... It sounds like that's fine, but he recommended to put the regulator at the heater end, so it would be 2psi going out there and reduced to .8 at the heater itself.

I still haven't pulled the trigger yet... Thinking I better get a permit before this work is done.
 
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Old 08-21-14, 01:56 PM
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the electrical is not going through the PVC. It will only be used for a 6 strand MM fiber, CAT6, and an RG11 coax (i.e. only low voltage will be fed through the PVC). Are you saying the buried PVC can't be used to feed low voltage?
It's still electrical work, just low voltage. Check with the AHJ, maybe they don't require a permit/inspection for low voltage work up there. Here, a separate low voltage permit and inspection is required. Here the PVC plumbing pipe is a code violation if it is used for any type of electrical work. I have mostly seen plumbing pipe used for electrical work on irrigation and landscape lighting jobs done by lawn/landscape contractors who aren't licensed and don't do permits. Why didn't you just use PVC conduit and remove all doubt?
 
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Old 08-21-14, 02:31 PM
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It's still electrical work, just low voltage. Check with the AHJ, maybe they don't require a permit/inspection for low voltage work up there. Here, a separate low voltage permit and inspection is required. Here the PVC plumbing pipe is a code violation if it is used for any type of electrical work. I have mostly seen plumbing pipe used for electrical work on irrigation and landscape lighting jobs done by lawn/landscape contractors who aren't licensed and don't do permits. Why didn't you just use PVC conduit and remove all doubt?
I just checked with my local building inspector and he confirmed I can use PVC conduit with no issue for data cables / optical fiber. To me running a cat6 cable is not "electrical work" - sure technically it carries dc voltage but from the inspectors point of view he's rightfully concerned with gas line and the 240volt AC line - not the low voltage line.

The reason I'm using this is because it came with the house. The previous owner roughed it in when they built the house in 2003. They never used it but it's there and in tact from point a to point b - although it had a couple gallons of water in it since they never capped it! My shop vac made quick work of that though!
 
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Old 08-21-14, 02:58 PM
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I just checked with my local building inspector* and he confirmed I can use PVC conduit
Conduit yes but if it is white it isn't conduit.
Correct it's white 1 1/2" PVC that's typically used for plumbing. However it also makes for a great conduit!
No it doesn't make great conduit because the inside has not been smoothed so it won't abrade the insulation on electrical wire. Did you ask the inspector about plumbing pipe or did you call it conduit?

*"checked with my local building inspector" but thats the wrong inspector. You need to ask the electrical inspector.
 
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Old 08-21-14, 06:57 PM
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Well, I guess it doesn't have the word "Conduit" printed on the side of the pipe, lol - thanks for pointing that out. But it's plenty smooth for 120' straight run to garage #2 - certainly not worth pulling it out of the ground a replacing - and again, this isn't "electrical wire" that's going into the conduit - it's a six strand MM fiber, a Cat6, and an RG11 coax. Those cables do not require a permit (in my township) - nor do they get inspected. What does get inspected is the 6AWG3 copper w/ground, and the gas line.

And this is the correct inspector - You may have a dedicated "electrical" guy where you live, in my township it's the same guy that does several types of permits and inspections from footing / foundation to plumbing and electrical - I specifically said existing White PVC that's typically used for plumbing - his response: I have no issues with you using that for low voltage wiring.

Apparently these code requirements vary widely depending on where you live.
 
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Old 08-22-14, 08:03 AM
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To me running a cat6 cable is not "electrical work"
Communications wiring is covered in Article 800 of the NEC.

And this is the correct inspector - You may have a dedicated "electrical" guy where you live, in my township it's the same guy that does several types of permits and inspections from footing / foundation to plumbing and electrical
That explains it, many rural areas do not have the funding to employ individual inspectors for each category and have general building inspectors.
 
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