400 amp service with two spare 2” pvc

I

iwirehouses

Senior Member
Hello, i have a job where i need to upgrade a service from 150amp to 400 amp (two 200 amp panels 120/240 single phase, underground). Problem is the underground is 282 ft to the pole. The existing service is in a 3” pvc (282 ft) 350mcm feeding 150 amp main breaker. There are also two spare 2”conduits, that i sucked all the water and dead chipmunks out of and are clean and ready. Is there any way to use them to pull conductors 282ft for a 400 amp service? I’d like to pull 300 mcm AL parallel, through the 2”. But at 282 ft, i have a feeling thats not going to be realistic. There is also the three inch thats in use. But i’d imagine id never get those conductors out. There are two 90’s in the pipe runs. Thank you for any advice
 
Three compact XHHW will be under the max fill for 2 inch sch 40. Is too much if there is any schedule 80 in the run, could convert to RMC/IMC or use reducing fitting to switch to 2.5" schedule 80 where you emerge from grade.

If using typical RHW/RHW-2 rated conductor it will be too much fill for 2 inch schedule 40 unless you can get the neutral reduced to at least 3/0.

This is long enough pull you will likely need more than man power to pull it, rig up pulley and pull with a vehicle, loader, tractor, or if you have an excavator, telehandler or similar can possibly pull up without extra rigging. Still helps a lot to have some help on other end to feed conductors into the raceway. Such setup can possibly pull the 350's out of the larger raceway.

Other question is what is actual load calculation, 350 can be fine if supplying multiple overcurrent devices if the calculated load is low enough, leaving you with voltage drop being a main reason to go larger if necessary.
 
I can't imagine those 90s surviving 282' of wire being pulled through at such a high fill rate.

Cut the 90s off on the ends, pull the wire through, and slip them back on when you're done. Don't tell me know one else has ever done this before. lol.
 
VirutalElectrician said:
I can't imagine those 90s surviving 282' of wire being pulled through at such a high fill rate.

Cut the 90s off on the ends, pull the wire through, and slip them back on when you're done. Don't tell me know one else has ever done this before. lol.
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wire pulling through isn't as big of a problem as the pull rope in many cases when it comes to damaging an elbow. OP also may not know whether the elbow is PVC or if they happened to put a RMC or even fiberglass elbow on there, or what radius the bend may be.
 
infinity said:
I think that pulling smaller copper conductors will solve your problem.
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Lets do some quick math...

250 xhhw copper is 7.90 a foot
350 xhhw al is 2.19 a foot

282x6x7.90=$13667
282x6x2.19=$3700

Copper is $9,962 more.

3" sch 40 is $50 a stick at menards....

282x2x$50 = $28,200. Plus labor to bury it....ouch..yeah copper might be the way to go.
 
My advice would be pull in 250 URD in each pipe and call it good. ITs not just fill, you have to be careful about jamming, and plexed conductors wont have jamming issues. As was mentioned you could fit larger than 250 if XHHW, but you would want them plexed. I have ordered plexed custom conductor sets, its usually not a big deal. Ask a few supply houses if their wire vendors offer that service.

I pulled about 700 feed of 250 URD feeding into a 90 with 2". IT was totally fine.
 
I'm wondering why 300s

Have you done a load calculation?
Are you trying to factor in voltage drop?

I would suggest seriously considering 4/0 or 250, and I would reduce the neutral at least one size.

4/0 would be 160 amps @ 4.4% voltage drop.
250s would be 160 amps @ 3.7% voltage drop.
250s would be 200 amps @4.6% voltage drop.
 
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