You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter gmtt
- Start date

- Status
- Not open for further replies.

- Location
- Macon,GA

I would use 2/0, this would ensure max 3% voltage drop. I assumed you were using copper.

- Location
- Seattle, WA

- Occupation
- Electrical Engineer

For a 240V single phase three wire, 500 feet long. I calculate a 4.61% drop with 3/0 copper

I would use 2/0, this would ensure max 3% voltage drop. I assumed you were using copper.

I also get 2/0

CM = 2 x K x I x D / VD

CM = 2 x 12.9 x 60 x 500 / 7.2 = 107,500

1/0 = 105,600

2/0 = 133,100

This is assuming that it is actually a 60 amp load not just a 60 amp OCPD. If this is a 60 amp OCPD than the actual load would probably be less than 60 amps. More like 60 X .8 = 48 amp load.

Thanks guys. I found a voltage drop calcualtor in the web. Actually it is a 30A generator pushing power to the 49th flr. I am using 2 AWG copper with a drop of 2.9%. Thanks.

If you're going

Thanks guys. I found a voltage drop calcualtor in the web. Actually it is a 30A generator pushing power to the 49th flr. I am using 2 AWG copper with a drop of 2.9%. Thanks.

Don't forget if you are using A EGC look at 250.122 (B).

- Location
- Macon,GA

Thanks guys. I found a voltage drop calcualtor in the web. Actually it is a 30A generator pushing power to the 49th flr. I am using 2 AWG copper with a drop of 2.9%. Thanks.

Can you share the one you found?

- Location
- Scotland Neck, NC

Can you share the one you found?

There is one on this site.

- Location
- Macon,GA

There is one on this site.

Yeah I am not too confident with that one to tell you the truth.

- Location
- Scotland Neck, NC

Yeah I am not too confident with that one to tell you the truth.

Bussman fuse site has one I think. I may have the spelling wrong so Google to get a selection. I got all the same answers that all the others got using the same parameters.

- Location
- Chapel Hill, NC

- Occupation
- Retired Electrical Contractor

Here is one calculator. #1 is what is needed if the load is 20 amps. If it is 15 amps then you need #2

Last edited:

- Location
- Scotland Neck, NC

Here is one calculator. 2/0 is what is needed.

This one gave the same results the other ones I tried. Works for me!!

- Location
- Chapel Hill, NC

- Occupation
- Retired Electrical Contractor

I edited my post And it is wrong. I see now that it is 60 amps and for that I get 2/0. 240 volts single phase. Damn I am carelessThis one gave the same results the other ones I tried. Works for me!!

Last edited:

- Location
- Roanoke, VA.

- Occupation
- Engineering

If you're goingupthe building, wouldn't the voltage get higher as you go?

I would also think it would slow down too....

I know I would.

- Location
- Scotland Neck, NC

Here is one calculator. #1 is what is needed if the load is 20 amps. If it is 15 amps then you need #2

That did not work for me!!!!:grin:

- Status
- Not open for further replies.