voltage drop

[bracemc]

I am having a bit of trouble figuring the formula for finding the max length a conductor can be when I know the CM, FLA, VD% and K. I have seen a few calculators that do this but I wanted to see the formula for myself to understand how it is figured.

Any help would be great.

 

[nakulak]

voltage drop =2 x k x I x L /(circ mils)


(change the 2 to 1.732 for 3 phase)

 

[bracemc]

voltage drop

Thanks. But I know the formula for the voltage drop, what I am looking for is what is the max length of the conductor(s) can be. I know the conductor size, VD%, cirmils, and K value.

If I know that I am going to be using #2 AWG with a max of 3% VD, how far can I run the wire before exceeding the 3%.

 

[augie47]

http://www.mikeholt.com/documents/freestuff/other/VoltageDropCalculator.xls

 

[nakulak]

L is the lenth, solve for L

is it single phase ? if so
vd= 2kil/cmils

cmils for #2 = 66360

what is the voltage ? is it 120 ? if so , 3% of 120 = 3.6 volts
is it copper ? if so k = 12.9

what is the current ? is it 100 amps ? if so
3.6 = 2 x 12.9 x 100amps x L /66360

you do the math

 

[bracemc]

voltage drop

The mike holt one did the trick. Thanks.

 

[augie47]

The mike holt one did the trick. Thanks.

that's what you pay me for

 

[LarryFine]

that's what you pay me for

Where's my cut? :-?