sub feed wire

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electricguy61

electricguy61

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Remotely running business in Bay Area, CA from Med
Hi folks

I have a job I’m quoting that will involve the main utility feed coming to a large metal garage, then feeding a 2100 square ft house @ 80’ away.

Both slab’s will have ufer grounding. Water fed to both likely non metallic.

Do I need to feed the dwelling with 3 or 4 wires? I’m on the 2014 NEC, and using the Handbook.
It appears I need to run a ground wire in addition to the three service conductors. Is there an exception I’m missing?

Thanks
 
electricguy61 said:
Hi folks

I have a job I’m quoting that will involve the main utility feed coming to a large metal garage, then feeding a 2100 square ft house @ 80’ away.

Both slab’s will have ufer grounding. Water fed to both likely non metallic.

Do I need to feed the dwelling with 3 or 4 wires? I’m on the 2014 NEC, and using the Handbook.
It appears I need to run a ground wire in addition to the three service conductors. Is there an exception I’m missing?

Thanks
Click to expand...
Correct NEC terminology - if you are on load side of service disconnecting means they are feeder conductors. If what you have is service conductors you don't need a EGC, you bond the grounded conductor to the service disconnect enclosure.
 
electricguy61 said:
That’s what I’m thinking. Feed through lugs on the meter/main, 4/0 4/0 2/0 URD plus #4 THWN in 3” pvc, to a 40 position NEMA 3R panel w/main (pretty sure they’ll require an exterior disconnect on the house for the fire dept)

Thanks to both of you
Click to expand...

I would not run URD. I would run a 2" raceway with individual conductors. You are not going to be able to terminate a 3" raceway to the customer side of the meter main at the garage or load center at the house.
 
curt swartz said:
I would not run URD. I would run a 2" raceway with individual conductors. You are not going to be able to terminate a 3" raceway to the customer side of the meter main at the garage or load center at the house.
Click to expand...

I will guess that what he is calling URD is really THWN/RHW or dual rated as such.

If he wants 3" conduit between structures, a 3" x 2" PVC reducing bushing before terminating would work.
 
jumper said:
I will guess that what he is calling URD is really THWN/RHW or dual rated as such.

If he wants 3" conduit between structures, a 3" x 2" PVC reducing bushing before terminating would work.
Click to expand...

Multi rated aluminum USE/RHW/RHH is fairly popular around here in a triplexed assembly, whether it is truly URD or not, IDK but many call it that.
 
jumper said:
I will guess that what he is calling URD is really THWN/RHW or dual rated as such.

If he wants 3" conduit between structures, a 3" x 2" PVC reducing bushing before terminating would work.
Click to expand...

Don't think he has THWN as he said this in the OP

electricguy61 said:
That’s what I’m thinking. Feed through lugs on the meter/main, 4/0 4/0 2/0 URD plus #4 THWN in 3” pvc, to a 40 position NEMA 3R panel w/main (pretty sure they’ll require an exterior disconnect on the house for the fire dept)

Thanks to both of you
Click to expand...

Those cables come with the 4/0 4/0 4/0 designation (or whatever size it is), and if a 4th wire there would be one more size listed. Such as 4/0 4/0 /4/0 2/0
 
Little Bill said:
Don't think he has THWN as he said this in the OP



Those cables come with the 4/0 4/0 4/0 designation (or whatever size it is), and if a 4th wire there would be one more size listed. Such as 4/0 4/0 /4/0 2/0
Click to expand...

Yeah,
I meant the Dual rated USE kwired mentioned. I hear it called URD a lot.

I posted without totally paying attention, happens a lot.:)
 
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