irishsparkie

I am looking at a job the would involve upgrading a 200 amp service too 400 amps. The existing service is underground, it is a 530ft run to the manhole, it is done in 2 1/2 inch PVC, and they used 250kcmil AL.
I plan on adding a second 200 amp main breaker panel next to the existing one and bringing in new 4/0 AL seu feeders to each panel.
I am wondering if there is a way that i can reuse this 2 1/2 inch pipe by pulling cu conductors. My question is if this is considered a 400 amp service or a 320 amp, due to the meter socket rating. If it is a 320 amp service i believe i can pull 500kcmil cu with a reduced neutral through this conduit and save the customer alot of money by not having to dig a new trench. Just hoping someone smarter than me can work out the voltage drop etc and come up with an answer. Thanks Guy's.

electricista

To figure vd you need to know what the load is. If you base the load on 400 amps at 520 feet you would need 750 kcm, however your load probably will be nowhere near that.

Given the 520 feet your 500kcm copper would only be good for 250 amps.

Here is an online calculator for VD

irishsparkie

So how do you explain the 250kcmil on the existing 200amp service?

480sparky

4/0 is all you need. T310.15(B)(6). Whoever put it in probably installed one size bigger to allow for a bit of VD, but keep in mind that upsizing for VD is not an NEC requirement.

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In winter, why do we try to keep the house as warm as it was in summer when we complained about the heat?

BryanMD

the EC had it in their warehouse?
and if they even did a calc the connected load was a low enough?

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November 2011: Relocated to Winston-Salem.
May have to change the username suffix.

480sparky

It's also possible the POCO installed it, and POCOs are not governed by the NEC.

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In winter, why do we try to keep the house as warm as it was in summer when we complained about the heat?

irishsparkie

So then there's no way to re-use the 2 1/2 inch conduit ?

480sparky

You can put 3 400 cu's in 2½" PVC per Table C.9(A).

3 400 cu's is good for a 400a resi service per T310.15(B)(6).

Have fun pulling in 530' of it, though!

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In winter, why do we try to keep the house as warm as it was in summer when we complained about the heat?

Speedy Petey

OUCH!! You are NOT kidding.

irishsparkie

Yes but are 400's still good over 530ft run ?

irishsparkie

So any of you guy's figure a price for something like this. I came over from Ireland ten yrs ago and i still haven't found my pot of gold, i was hoping getting into this trade would do it, been in the trade on my own for a year now and haven't made a buck......lol.

wirenut1110

I guess it may be your area but, are you responsible for the line side of the meter?

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Jim

irishsparkie

Yes all the way (530ft) back up the drive-way to the manhole, where it ties in with the poco.

electricista

If you use the vd calculator that I linked to you will see that the 400's are good for 200 amps for that distance.

Speedy Petey

You need to get the exact cost of the wire first. 1600+ feet is a lot of big copper.
Consider what a $.50 per foot cost increase would do to you if you figured it wrong.

irishsparkie

But if you put in the 200amp service that is currently there, and the 530ft, the calculator requires 700's, and it only has 250.

480sparky

Where is voltage drop required to be addressed in the NEC?

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In winter, why do we try to keep the house as warm as it was in summer when we complained about the heat?

irishsparkie

So you dont think the 530ft run is a factor ?

480sparky

I do, but the NEC doesn't.

__________________
In winter, why do we try to keep the house as warm as it was in summer when we complained about the heat?

irishsparkie

Im pretty sure the poco would have something to say about it.