# 800 amp service



## Bootleggersboy (Oct 1, 2008)

I have an 800 amp service and the distance from the power company's transformer to the meter can is 500'. What size conductors should be used? The service is single phase 120/240 v. and the load will be around 575 amps...Any help you can provide will be greatly appreciated.


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## sparky970 (Mar 19, 2008)

I think if I were doing this, I would pull parallel 500's.


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## Speedy Petey (Jan 10, 2007)

You say you have the service? Is it already installed? Or is this a new job you are doing?


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## waco (Dec 10, 2007)

Interesting. How many meters and panels do you mean to have? Most residential (single phase) sockets I'm familiar with are rated 320 amps, tops.


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## ralph (Apr 6, 2008)

waco said:


> Interesting. How many meters and panels do you mean to have? Most residential (single phase) sockets I'm familiar with are rated 320 amps, tops.


Probably has a ct cabinet

2 sets of 500's


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## Speedy Petey (Jan 10, 2007)

ralph said:


> Probably has a ct cabinet


Yeah, but he says _"...from the power company's transformer to the meter can is 500'.."_.
The conductors from the pole do not go to the meter pan in a CT metered service.

Also, a 575A load? In a residence I find this hard to believe. Commercially why not go three-phase? Maybe it was not available at the location?

A LOT more information is needed here.


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## bobelectric (Feb 24, 2007)

My neighbor across from me (3/4 mile) has a 800 amp service.Switch gear like you see in an office complex. 4 200 amp subpanels.


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## nolabama (Oct 3, 2007)

square d easy pacs are 800+ amps for resis - i have set several 800 and 1200 amp easy pacs - i cant remember off the top of my head what the size was - if i remember right it was three 600 mcm aluminum per phase for the 1200 amp and three 400 mcm aluminum per phase for the 800 amp panels
oh btw what does the engineer say - you gotta have an engineer drawing for this service - no drawing, no permit, no inspection


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## nolabama (Oct 3, 2007)

online calculator says 500' and 550 amps ( maximum range btw ) is 2000 MCM


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## Mountain Electrician (Jan 22, 2007)

Bootleggersboy said:


> I have an 800 amp service and the distance from the power company's transformer to the meter can is 500'. What size conductors should be used? The service is single phase 120/240 v. and the load will be around 575 amps...Any help you can provide will be greatly appreciated.


Seems odd you need to calc the service entrance conductors. Here we install them, but the POCO does all the engineering. Anyway, if you're worried about voltage drop, don't be. An 800A service would take parallel 500KCM, and at that wire size, length and load you stated the VD would be around 7.5 volts.



VD=2R X L X I
____________

CM

Voltage drop is equal to 2 times the resistive property of the conductor per foot(2R), times the length(L), times the load(I), divided by the conductor area in circular mills (CM) 

NEC Chapter 9, Table 8 has these properties.


The resistive prop of copper is around 12.9 and you would divide the load in half for the parallel conductor, so:
26*500*287.5 = 3737500/500000 =7.47

drop of around 7.5 volts per cable

Max suggested VD is 5% of 240, or 12 volts.


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## chenley (Feb 20, 2007)

Same here, POCO will install conductors from transformer to meter. If going underground they will tell me the type and size of conduit they want and we just have to install the peice going down and the 90, they do the rest.


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## brian john (Mar 11, 2007)

sparky970 said:


> I think if I were doing this, I would pull parallel 500's.


 
Why guess?

http://www.csgnetwork.com/voltagedropcalc.html


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## nolabama (Oct 3, 2007)

thanks for the new calculator brianjohn
oh and it must be nice for your pocos to do that stuff for you 

the condo project with the easy pacs we had to provide the conductors from transformer to meter and we had to provide the drawings 
it guess it depends the last underground i did they provided conductors


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