400A overhead service

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jcole

Senior Member
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Lawrenceburg, Kentucky
Hey guys and gals.

Need to do estimate on a 200A to 400A overhead residential service upgrade. Ive not ever done 400A overhead service. Just need some opinions.

Is it more economical to install two 2.5" risers with 4/0 aluminum parallel conductors down to meterbase. This would probaly include a trough because I dont think my suppliers 400A meterbases have two hub connections.

The other way would be one 3" riser with 600 kcmil aluminum conductors down to meterbase. This seems to be the easiest way. But I dont think my supplier has 600 kcmil in stock.

I would like to use aluminum conductors for obvious financial gains.

How do you guys nomally do these type of services? What type of conductors do you use?
 
""Is it more economical to install two 2.5" risers with 4/0 aluminum parallel conductors down to meterbase.""

Time is money and steel aint cheap. I'd use a single riser


"This would probaly include a trough because I dont think my suppliers 400A meterbases have two hub connections.""

Skip the trough. Time is money. Use an all in one.

Where are your branch circuits? At the service location ? In another part of the building?

If the BC's are at the service location, use an all in one panel. Two 200 amps mains. One feeds a 40 space bus in the panel the other is used to feed another 200 amp panel right next to it or wherever you chosse.

If all BC's are elsewhere I can have a can built locally with a meter and 2, 200 amp pullouts , then run your feeds in the apropriate manner.


""I would like to use aluminum conductors for obvious financial gains.""

Backwards logic. If you mark up your materials you will gain more financially if you use copper. Also, double check your wire sizes. I BELIEVE there is an exception for service entrance conductors that allows dropping down a size.

""How do you guys nomally do these type of services?""

As efficiently as possible.


" What type of conductors do you use?"


I use only use copper.
 
Thanks for the reply John.

I understand the more money I have in material the more money I wil make do to markup, but I was trying to be the lowest bidder and still hit my profit margin. The project is within a mile of my house so I would like to get it. According to Table 310.15B6 I have stated the correct sizes for aluminum service entrance conductors. If I use copper than I can drop down to 400 kcmil.

The reason I was contemplating the two riser method is because my supplier does not supply conductors that large, aluminum or copper. The supplier closest that would is about 20 miles away.

But whats 20 miles? I just add another 1.5hrs to the estimate to cover my time. Thanks again.
 
I was trying to be the lowest bidder and still hit my profit margin.
Click to expand...

Try not to fall into THAT trap.

Bid the job high enough to be happy and to be able to do an excellent job.


Post this on your desk: You NEVER want to be the low bid....EVER.
 
ok...you are tripping over dollars to chase pennies....

how tall is your riser? 15 feet? how much savings in using aluminum?

meter can should have double lugs..

1 riser w/ 400 cu or parallel 2/0 in it ( don't know the derating off hand)

get your material delivered!
 
jcole said:
But whats 20 miles? I just add another 1.5hrs to the estimate to cover my time. Thanks again.
Click to expand...

If you can do 40 miles round trip in 1.5 hours you're definately not from around here. 1.5 hours is the counter wait time!
 
Milbank makes 2 different meter bases for either a parallel 2" or a single riser up to 4"
I just installed one for a commercial application and they are rated for resi. use.
Part # U1079-R
Go to www.milbankmfg.com and download the .pdf file
 
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Thanks for advice. But around here work is slow and lowest bid has been getting the work. I feel as long as I am hitting my profit margin and doing safe, reliable work that being the lowest bid cant be to bad. I see your point though.

On doing the adjustment factors for 310.15B2a, can I use the ampacities in 310.15B6 or do I have to use 310.16? I think I would have to use 310.16 according to Table 310.15B2a.

That would put me at 250kcmil copper if I parallel. If I dont parallel I could use Table 310,15B2a (400kcmil). Agree?

I was checking Annex C for conduit fill for this. What is the difference between conductor and compact conductor?

Thanks again guys.
 
Thanks for advice. But around here work is slow and lowest bid has been getting the work. I feel as long as I am hitting my profit margin and doing safe, reliable work that being the lowest bid cant be to bad. I see your point though.

On doing the adjustment factors for 310.15B2a, can I use the ampacities in 310.15B6 or do I have to use 310.16? I think I would have to use 310.16 according to Table 310.15B2a.

That would put me at 250kcmil copper if I parallel. If I dont parallel I could use Table 310,15B2a (400kcmil). Agree?

I was checking Annex C for conduit fill for this. What is the difference between conductor and compact conductor?

Thanks again guys.
 
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