wire size calculator

Thanks, Grant

Here is one that I have used.

http://www.stanselectric.com/vdrop.html

I am installing another pump 800 feet from my 200 amp 600V splitter. The new pump is 15 HP 600 V - about 15 amps to run. I run all Al ACWU underground because it is cheaper than Teck 90 Cu.

I do get my neighbor - electricion to do the install, but I like the wire size calculator because it gives me a good idea where to locate my pumps without having to call him every couple of days.

I think the site I had the link for was Paige Point Power or something like that. I had it saved in favorites, but it seems to have dissapeard (my wife was house cleaning).

Thanks again, I am sure I will figure it out, if not I will pester my neighbor.

If you google on "wire size calculator", a whole bunch of links come up. The link for Paige is below, but it only goes to 480V.

Here's my calculations, for what it's worth.

Voltage: 600Vrms phase-to-phase
Power: 15 HP
Power Factor: Assume 0.7

Power in Watts equals 15 x 746 = 11,190 W
Power per phase equals 11,190 / 3 = 3730 W
Volt-amps per phase equals 3730 / .7 = 5328 VA

Phase to neutral voltage equals 600 divided by the square root of 3 (1.7) equals 346 V

Current per phase equals 5328 / 346 = 15 amps! You were right.

Now to figure voltage drop per phase

10 ga Cu: 1 ohm per 1000 ft. times 800 ft at 15 amps equals 12 volts per phase = 3.5 percent

8 ga Cu: .8 ohm per 100 ft is 10 volts or 3 percent.

Assuming that a three percent voltage drop is acceptable, 8 gauge or larger copper should do the trick. Of course, bigger is always better.

• Paige Wire Size Calculator

The bit I'm not sure of is how to calculate the current per phase. Lets say we have a 1KW machine at 48V. Thats give or take 20 amps (at high production the battery voltage will usually rise to abut 50V).

On a three phase generator with three wires (no neutral) is the current simply 20 divided by 3 or is it 20 divided by the square root of 3? Can't seem to find this anywhere.

Best wishes, Quentin.

Thanks again, Grant

Thats about what I figured - I will probably use 6 or 4 Al ACWU.

Thanks everyone for you advice and replies, Grant

The wire doesn't know if it's hooked up to single phase or three phase. It only has two ends!