Question regarding Making 220 Volt Extension cord

[Douglas Robinson]

I want to make a 200 Volt extension cord. I know what connectors I need. It will run from a 20 AMp outlet. What wire should I use? 10/3? 12/3? I know it needs a ground wire.

Doug

[rhett]

I would prefer 10/3, but I tend to over do everything. Its always better to have to much than not enough.

[chris99z71]

Check here
SOOW & SJOOW
Remember that the amperages listed are probably for short runs. If you're going to be making a crazy long length, I'd go up a size. There are others on this site who know 1000 times more about electrical stuff than me, but that should get you started.
I think I'd go 10/3 if it was me...
Lowes and HD both carry SOOW and SJOOW, although their offerings are limited and you could probably do better buying from an electrical supply house.
Hope this helps.
Someone please shout if I'm off on any of this.

Edit: FWIW, I think I paid about $1.85/ft for 10/3 SOOW at HD. Of course copper has come down some since then.

[woodworker2000]

12 gauge wire is rated for 20 amps but the proper gauge will depend the length of the extension cord. If this is for your shop area (one-car garage), 12 gauge would work just fine. Anything more would be overkill.

If this is for your new saw, you might consider running a new wire directly from the motor instead of making/using an extension cord. You will save a few bucks by not buying the additional plug ends.

[BumoutBob]

Hold on!!! Save some money---First how many amp are you going to pull? For instance, if you have a 1HP motor running on 120VAC it could pull 13 AMPs. If you wire that same motor for 220VAC the current is cut in half(6.5 Amps). The motor would run on a standard 16 AWG extension cord(10 AMP rating) It would easily run on 50 to 75 feet. The formula is E =IR Voltage (E) when doubled will allow the Current(I) to half when the resistance (R the motor winding) stays the same. This is Ohms Law.

Note too that the breaker for 220 VAC need not be large--if you can find a smaller one. A 15Amp breaker (220VAC) dual switch is large for a 6.5 amp load.

Rule of thumb run 3/4 of the rating of the wire/breaker capacity for motor over load capacity. A little more if the length is below 25 feet

16 AWG wire is rated at 10AMPs
14 AWG wire is rated at 15 Amps
12 AWG is rated at 20 Amps
10 AWG is rated at 30 Amps

[Jim Murphy]

For most of your 220 volt tools, you don't need XX-3, you can use XX-2 w/Ground. The xx-3 actually has four wires: black, white, red and a bare ground. The only time you need XX-3 is if you have a 120 volt element (for example, the lights on the dryer) that needs the white for a return. Almost all 220 volt tools use black/white/ground. That's it. And with copper the price it is, no sense paying for extra metal when you don't need it.


Is this for the PM2000?

[scsmith42]

Ditto Bob and Woodworker's comments - the size of the cord depends upon the load that you plan to put through it as well as it's length, and the type of conducter in the cord.

The recommendations regarding using a "SO" type of cord are right on, as these usually have a high count stranded connector which will carry more amps.

The other consideration is 3 wire versus 4 wire. Current code would call for a 4 wire cord (two hots, a neutral and a ground), and quite frankly the separate ground wire is a good idea. Having said that; many folks have used three wire cords (two hots and a neutral) for years with success.

If you can let us know the length of cord and amperage capacity (or motor type) you plan to use it with, we can advise as to the minimum conductor size.

Regards,

Scott

[Jim Murphy]

Scott, if you run XX-3 w/ ground directly to the contactor, where do the four wires hook up? If you have a sub-panel, the ground and the neutral are isolated.

And Doug, make sure you don't undersize based on the breaker you're drawing from. If it's a 30 amp breaker and you run 12, that's a risk of overheating the wire before the breaker trips. OTOH, there's no problem with upsizing except you're wasting money. Best advice is if the breaker is 20 amp, run 12, if 30 amp, run 10, if 40 amp, run #8.

IANAE (I am not an electrician) but I believe code requirements for XX-3 w/ground apply to dryers and things with a 110 volt need.

[scsmith42]

Jim, re the 4th wire, the answer is "it depends".

The original question was about making an extension cord. Thus, the 4th wire would simply terminate into a 4 wire plug / receptacle, such as a twist lock.

If you're terminating directly to the equipment, as you indicated earlier it's required if any portions of the equipment have 120volt components. In that instance the 4th wire is a chassis ground.

Scott

[MikeH]

Wow, I have no idea what the heck you guys are talking about.

[alleng]

for 220 there is no netural,black to one leg and white to the other,and green to ground.

[chris99z71]

Originally Posted by fernhollowman

For most of your 220 volt tools, you don't need XX-3, you can use XX-2 w/Ground.

That's exactly right. The only exception is the SOOW/SJOOW cord. It does not have a bare ground. SO- labeled XX/3 has a black, a white and a green with no bare ground.
All good advice on oversizing your wire with respect to your breaker. Yes, 10/3 is a little more than 12/3, but it's not like you're buying 1000' of wire. The price difference is ~$0.30 to $0.40/ft. So to me, it's worth it to have that much extra protection in my home to justify spending an extra $12 on a 30' extension cord.
Again, just my $0.01

[Douglas Robinson]

Thanks for the feedback. Yes this is for the PM2000. I only want about a 10 ' cord to maximize manueverability in the 1 car shop. The breaker is 20 Amps. The motor is a 3 hp.

Doug

P.S> I like hpm67's comment

[MikeH]

Originally Posted by Douglas Robinson

Thanks for the feedback. Yes this is for the PM2000. I only want about a 10 ' cord to maximize manueverability in the 1 car shop. The breaker is 20 Amps. The motor is a 3 hp.

Doug

P.S> I like hpm67's comment

Thanks Doug. I know next to nothing about electricity so I feel dumb when you guys start throwing around all these specs.

[Jim Murphy]

Originally Posted by scsmith42

If you're terminating directly to the equipment, as you indicated earlier it's required if any portions of the equipment have 120volt components. In that instance the 4th wire is a chassis ground.
Scott

Not to pick at bones, but to prevent confusion to others, the "4th wire" is a neutral for the 115 volt side of the circuit. The third wire is a ground. There is always a ground in a proper circuit, but, as explained elsewhere in the thread, no neutral in a 230 volt circuit. 230v is Hot 1, Hot 2, and ground. Hot 1 and Hot 2 do the work. Lose the ground and the motor will still run, although not recommended for safety reasons. (Won't harm the motor.)

If, for example, your power equipment had a 230v motor and a 115v worklamp, the 230v motor would use the black and red. The 115v lamp would use either the black or the red, but would need the white neutral to work. The ground, whether insulated or bare, is just that, a ground, and is connected directly to the equipment frame by the mfr.

Old code allowed dryers and stoves to use the ground as a neutral return for the clock, timer, lights, etc. (the 115v stuff). In the main panel, the ground and the neutral are tied together, so it worked just fine, but there was the risk of energizing the frame of the stove/dryer. Recent code requires all four wires.

And if none of this makes any sense, then DON'T attempt your own shop wiring. Know when not to do it yourself.

Jim