Parallelling resi feeder - Electrician Talk - Professional Electrical Contractors Forum

bharbwyr · 10-09-2009, 10:41 AM

This is my first job where I think I will have to parallel the underground. The run will be close to 500'. This house was originally going to be off-grid, but the situation changed and now the architect/owner is thinking he has to add more and more loads. We're shooting for something in the range of 125-150 amps @ 3% VD. Two runs of 4/0 seems to be more cost effective than one of 500kcmil (by around $1500. my cost). I'm hoping to direct bury mobile home feeder. One of my questions is: Can I make one run triplex and the other one quadriplex if they are in close proximity to each other? Also, can I bug and tap the runs within the 200A milbank metermain enclosure and the 200A square D QO panel? Any suggestions would be greatly appreciated.

Speedy Petey · 10-09-2009, 12:55 PM

You really think you need parallel 4/0AL for 500'? I would think single 350 would be fine.

How are you figuring VD?
What does your POCO say?

wildleg · 10-09-2009, 10:57 PM

I must be missing something. why do you need quadriplex ?

JohnJ0906 · 10-10-2009, 06:45 AM

Quote:

Originally Posted by wildleg

I must be missing something. why do you need quadriplex ?

Quote:

Originally Posted by bharbwyr

Also, can I bug and tap the runs within the 200A milbank metermain enclosure and the 200A square D QO panel? Any suggestions would be greatly appreciated.

It seems he is running from a metermain to the house, which would mean an EGC is needed.

If this is the case, remember 250.122(B) and (F)

bharbwyr · 10-12-2009, 01:26 PM

Right. This is after the meter. And I did the calc.s longhand and using a online program (they agreed! Yea!)but got mentally hung up in that my suppliers did'nt carry the 350 in quad. It looks now like I will be going with the 350 use-2 and add a #1 for the EGC. That should give about 119 amps @ 3%VD