VD for Length

[FranklinMade]

Anyone have a VD formula for length?
Like if I had a 50 amp 240v load how far could I run it? Anything would help. Thanks!
2xkxi / cm/vd?

 

[retirede]

https://www.southwire.com/calculator-vdrop

 

[HEYDOG]

Anyone have a VD formula for length?
Like if I had a 50 amp 240v load how far could I run it? Anything would help. Thanks!
2xkxi / cm/vd?

For single phase it is L = VD * CM / 2 * K * I

 

[FranklinMade]

For single phase it is L = VD * CM / 2 * K * I

So it would be…..
7.2(3%of 240) x 10380(#10) divided by 2 x 12.9 x 50?

 

[FranklinMade]

For single phase it is L = VD * CM / 2 * K * I

What would be an example?

 

[HEYDOG]

What would be an example?

First off a #10 awg is not big enough for 50 amps. A example….. A 240 volt single phase circuit is feeding a 24 amp load using #10 copper conductors. What is the maximum length this circuit could be and not exceed 3% voltage drop?

 

[FranklinMade]

First off a #10 awg is not big enough for 50 amps. A example….. A 240 volt single phase circuit is feeding a 24 amp load using #10 copper conductors. What is the maximum length this circuit could be and not exceed 3% voltage drop?

Yes that would be correct. So how would you write out the problem

 

[FranklinMade]

Yes that would be correct. So how would you write out the problem

7.2 x 10380 / 2 x 12.9 x 24 ??

 

[mayanees]

Hey FranklinMade,
A sanity check is that you don't need to upsize unless you run farther than the voltage in feet. So for 120 Volt, you can run 120 feet. 480 Volt, 480 feet. It's not exact, but it's worthy.

 

[Dsg319]

 

[FranklinMade]

View attachment 2563543

Thank you very much!!

 

[kwired]

It is algebra, you need to know how to rewrite the formula to find the missing figure.

simplified example a + b = c

if you already know what a and c are and need to find b then it is rewritten c - a = b.

 

[FranklinMade]

It is algebra, you need to know how to rewrite the formula to find the missing figure.

simplified example a + b = c

if you already know what a and c are and need to find b then it is rewritten c - a = b.

Thanks! I need to start taking school again

 

[Carultch]

Thanks! I need to start taking school again

Use the formula triangles, like Dsg319 showed at the top of the paper.

It is very common to have a formula in the form of A = B*C. Usually with a meaning behind the formula of "cause = resistive property * effect".
Draw a triangle with A on top, B on the bottom-left and C on the bottom right. Cover up the unknown, and you'll see your expression for it, in what remains.