Where would I buy magnet wire?

Question

and what gauge will adequately support 3000 amps with 26 volts? I am winding it up and using about 15,000 feet, I think.

I dont really know how to do the math to figure out how much footage I will need. I am putting it on a spool with a 22" diameter , and 5" inch depth; and my iron core is 4.5" diameter, and 5" depth.

I have been trying to figure it all out, and I keep coming up with 28,000 feet - the amount that I will need to fill the spool. - that is working with a wire that has a 2 millimeter diameter . A wire with a 3 millimeter diameter comes out to 14,000 feet? does that even sound right?

Answer 1

Your numbers are all scrambled. 2mm wire is good for 40 amps before melting, 3mm for 60 amps, but that's a far cry from 3000 amps!

How much length? depends on how many turns, which depends on the magnetic field you want, and on the core.

But again, your numbers are wrong. 15000 ft of wire to support 3000 amps is probably all the copper in a city.

Start at the beginning and list what you want to do, in detail.

Answer 2

If you are playing with a power supply that will deliver 3000 amps,  you need to consult an expert.  Assuming you are dealing with conventional electromagnets here, not  using superconducting wire, and you are dealing with sustained magnetic field, not a pulse magnet, then you are taling about 3000 amps at 36 volts AC. 3000 amps can generate a lot of heat in a short amount of time.  Since the voltage is low, large arcs are probably not your biggest problem but, if you start melting your wire or some other part of your electrical circuit, things can go bad in a hurry. Get some qualified engineering design help.

As far as length of wire and how much will fit in a given volume, do some modeling with wire on small spools.  It may help if you make an assumption about how much of the volume is wire, how much is insulation, and how much is air.  Then treat it as a "solid", calculate the weight, then back calculate the length of wire that will give you the calculated weight.   Whenever you are doing calculations, be careful with units (you mention feet, mm, and inches).  Good luck

Answer 3

Is this 3000 amps pulsed? If not you are going to need a few million dollars worth of wire.

Answer 4

To figure how much wire you need to fill a spool:-

1) Figure the volume of the spool.

2) Multiply by a "packing factor" of 0.5

3) This is the volume of wire that you will need. Divide by cross sectional area to get the length.

There are certain exotic winding methods that will give packing factors greater than 0.5, but this is a good working value.

Volume of spool = PI(11^2 - 2.25^2) = 1821 cu. inch.

Volume of wire = 1821 * 0.5 = 910 cu inch

Wire diameter = 0.080 inch (2mm)

Wire XC area = PI(0.04^2) = 5.03E-3 sq inch

Wire Length = 910 / 5.03E-3 = 181E3 inch = 15,100 ft.

You probably left out the packing factor in your calculations. This coil will not take anything like 3000 amps at 26 volts, which is 78kW. You will be lucky to dissipate even 200 watts in a 22" diameter coil.

Edit:-

3 batteries in series will give about 24 volts at 1000 amps. The voltage per battery drops to about 8V, and series connection does not increase the current. You need a EE to design a proper magnet, the way you are going you will just get a fire ball. Dimmers work off AC, not DC.

Answer 5

3000 Amps would take a wire thicker than 1 inch in diameter see

http://www.powerstream.com/Wire_Size.htm

And 1000 feet of that wire would weight a lot!

What are you doing?