Originally Posted by Bootleggersboy
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
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.