Running 200A service wire in PVC under slab

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Stuntman

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Midwest
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Electrical Engineer
Installing 200A main panel in an outbuilding. I have to run 200A direct bury wire (4/0-4/0-2/0) from the emergency disconnect to the (65') building and stub it up, the LB it through the wall then run in conduit to the utility room (another 40')

However, there is an underground pipe, 2" white plumbing PVC" that stubs up in the utility room, and runs under the concrete slab and exits through the footing of the garage. If I could muster pulling the service wire through this, it would substantially simplify the installation.

I realize that white plumbing PVC is not the same as conduit, but could it be used in this application that is nearly all underground?
 
Stuntman said:
Good point... Long sweep 90 (plumbing)
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That is way less of a radius than what is required in Chapter 9, Table 2. My understanding is that a plumbing long sweep has a radius of about 1.5 times the diameter of the pipe, or in your case a radius of 3", where the table requires a radius of 9.5".
 
Stuntman said:
Installing 200A main panel in an outbuilding. I have to run 200A direct bury wire (4/0-4/0-2/0) from the emergency disconnect to the (65') building and stub it up, the LB it through the wall then run in conduit to the utility room (another 40')

However, there is an underground pipe, 2" white plumbing PVC" that stubs up in the utility room, and runs under the concrete slab and exits through the footing of the garage. If I could muster pulling the service wire through this, it would substantially simplify the installation.

I realize that white plumbing PVC is not the same as conduit, but could it be used in this application that is nearly all underground?
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Triplex wire is usually URD, which you can't run inside the building. So you'd have to transition to SEU.

Also, is the emergency disconnect fused? If not, I don't believe they'd allow 40' of unfused service wire running through the building like that.
 
We would not allow a white PVC pipe to be used as a conduit on permitted work. Ostensibly, that would be based on not being a listed wiring method per 352.6, but the reason we enforce it is that if someone digs up a white pvc pipe in a yard or finds one in a wall, they expect to be able to cut it without arc blasting their Sawzall blade. Then, you wonder how a plumber in a hurry will patch the wiring back together...

I have allowed it before if they spray paint the pipe grey.

Stuntman said:
Installing 200A main panel in an outbuilding. I have to run 200A direct bury wire (4/0-4/0-2/0) from the emergency disconnect to the (65') building and stub it up, the LB it through the wall then run in conduit to the utility room (another 40')
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Pulling hot-hot-neutral-ground of that size in a 2" would really suck. Definitely a hold-my-beer type of endeavor.
 
NEC Inspector said:
We would not allow a white PVC pipe to be used as a conduit on permitted work. Ostensibly, that would be based on not being a listed wiring method per 352.6, but the reason we enforce it is that if someone digs up a white pvc pipe in a yard or finds one in a wall, they expect to be able to cut it without arc blasting their Sawzall blade. Then, you wonder how a plumber in a hurry will patch the wiring back together...

I have allowed it before if they spray paint the pipe grey.
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If the white PVC is just a sleeve for DB wire, I don't see how you could not allow it.
 
Little Bill said:
If the white PVC is just a sleeve for DB wire, I don't see how you could not allow it.
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Even as a sleeve the radius of the 90 would have to be large enough to accommodate the minimum bending radius of the cable being installed. However not sure there is a bending radius for the type of cable being used.
 
Yes, this wire would have an emergency disconnect right by the meter before being buried. Overall, I am getting the impression this is a bad idea (even though that would have been handy).

VirutalElectrician said:
Triplex wire is usually URD, which you can't run inside the building. So you'd have to transition to SEU.

Also, is the emergency disconnect fused? If not, I don't believe they'd allow 40' of unfused service wire running through the building like that.
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I was also under the impression I could not run URD in a building due to insulation fire rating. Then I was informed that the insulation rating would be OK if put in appropriate conduit inside the building. Sounds like this is not the case?

Thanks for the feedback
 
Stuntman said:
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I was also under the impression I could not run URD in a building due to insulation fire rating. Then I was informed that the insulation rating would be OK if put in appropriate conduit inside the building. Sounds like this is not the case?

Thanks for the feedback
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URD is not an NEC cable type and is not permitted for any NEC installations. That is typically a utility cable and, if aluminum, may have the old EC-1350 aluminum alloy.

If you have USE without any additional markings, then 338.12(B) would prohibit that cable from being used inside. It must terminate in an exterior enclosure.

If you have USE with an additional marking such as RHH or RHW it can be run into a building
 
Stuntman said:
Installing 200A main panel in an outbuilding. I have to run 200A direct bury wire (4/0-4/0-2/0) from the emergency disconnect to the (65') building and stub it up, the LB it through the wall then run in conduit to the utility room (another 40')

...
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Not your question, but I'd consider 40ft to be a violation of 230.70(A)(1) or 225.32 "nearest the point of entrance".
 
jaggedben said:
Not your question, but I'd consider 40ft to be a violation of 230.70(A)(1) or 225.32 "nearest the point of entrance".
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Good point. Previous jobs have always inherently had a disconnect right at the structure. This setup is significantly different and looks like this underground route is not a possibility.
 
Speaking of white PVC it is commonly used for air intake and flues on high efficiency boilers and furnaces although it was never listed for that use it has been used for that for over 30 years.

The trend is to get away from it for flues as the temp rating of pvc isn't high enough and some of it has deteriorated and turned brown from overheating over the years in addition most of it was never listed for that use although IPEX does have PVC that is listed for flues.

Most now are using Polypropylene for flues and PVC is ok for air intake

MA ( I don't know about other states) require stickers to be put on the air intake and flue pipes on all new installs and replacements markes " AIR INTAKE" or "FLUE PIPE" The heating supply houses sell them

Apparently more than one HO or plumber has cut into them thinking they are a plumbing drain or a plumbing vent
 
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