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Cable size , service size, Ampere , voltage drop

Cable size , service size, Ampere , voltage drop

Cable size , service size, Ampere , voltage drop

(OP)
Hi
I asked to move 3 phase transformer to new pole.
This 3 phase transformer is feeding apartment building from pole to underground service.
Currently this tx 3-50kva ,600/347 V, 4-4/0 Al.
they gave me the peak load on tx is 135 kva.
77 residents in apartment all 120/240. But i don't know the main Ampere going to building.

my new pole is meter or 240ft away from current location.
I don't know the service size (A) ampere in apartment.
so i don't know how to calculate voltage drop based on new distance.
What cable size should I use? and what is actual size Ampere in there?

RE: Cable size , service size, Ampere , voltage drop

This forum is intended to provide help, but not to do your work. There's enough threads dealing with voltage drop calculations already in this forum. I suggest you start there.

RE: Cable size , service size, Ampere , voltage drop

You were given the peak load on the tx in kVA and its kVA rating and you know the voltage level, but you can't find the current for cable sizing? You may feel I'm harshly saying the following, but the engineering code of ethics requires me to put the safety of the public foremost: If you have no knowledgeable support for this task within your company, you are attempting to practice engineering outside the area of your competence and should look for a new job.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.

RE: Cable size , service size, Ampere , voltage drop

You should start by reading the applicable electrical codes and calculating the service size according to the code that you work under.
Under the code that I am subject to, I must use the calculated demand load to calculate the voltage drop.
My code book has voltage drop tables and instructions on how to use them.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Cable size , service size, Ampere , voltage drop

(OP)
Thank you all for the pointers.

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