10/2 or 10/3

[Jason Yeager]

Hello

I am wiring a garage/shop and am trying to figure out which wire to take to my 220 outlets with. I don't have any tools that require 220, but want to have the wiring in should I acquire a some 5 h.p. machinery. 10/2 is quite a bit cheaper, so if I could get by with that, that would be great, but don't want to wish later that I would have run 10/3.

Thanks

[Mike Henderson]

Maybe one of the other electrical people can correct me, but I don't see why you'd need 10/3 for 240V. You only use two wires, plus a ground, to wire up a 240V outlet. There' no need to carry neutral to a 240V outlet.

Mike

[Andy Bardowell]

Mike’s right Jason you only use a three wire for appliances such as stoves and dryers that need both 220 and 110 for accessories, etc.

[Tom Veatch]

Mike and Andy gave you good advice. I'll only add that if you're running NMC, you can use the exact same 2 conductor + ground cable for 240v circuits that you'd use for 120v circuits of the same amperage. You'll need to identify the white wire as a "hot" wire at accessible locations using colored tape, heat shrink tubing, or other identification acceptable to your local electrical inspectors. If you're pulling separate wires inside conduit, you'll need two conductors that are colored other than white or green.

[Mike Cutler]

10/2 and make white black. AWG 10 is hard enough to work with, no reason to make it harder with an extra conductor.

[Scott Wigginton]

Ditto what others have said, I'm using 20 Amp breakers for both my 110 & 220 outlets so I ran 12-2.

Size your outlets to your future "upgrades", for me that's mostly 3 HP tools so the 20 Amp breakers is fine, but if you want some 5 HP then definetely run a separate the 30 Amp/10-2 gauge now so it'll be there when you're ready.

[Rick Moyer]

The simple answer is 10/2 is what you want.

I am currently (pun intended) wiring my garage/shop and I ran all 12 ga. in conduit as I think over 3HP is overkill for a home hobby shop and I don't plan on getting 5HP and larger equipment. Of course you never know. I could always run 10ga. in there if I had too later, though. If you are running wire in the wall you may want to use 10 ga., although I still wouldn't for the extra expense and trouble.

[Eric DeSilva]

AWG 10 is hard enough to work with, no reason to make it harder with an extra conductor.

Amen. That stuff is thick and stuffing 10/2 into a box can be a real pain--go for the deep boxes if you are doing a new install. I've been contemplating rewiring a 220V circuit in my garage with 6/2 for a welder, and am finding it really easy to put the task off.

[Jason Yeager]

Thanks fellas,

10/2 it is, kind of like flyfishing...

Cheers

Jason

[James Benson]

The code for wiring 30 amp 220 Volt in Calif. is for 4 wire cable(one for both hots, a neutral, and a ground wire). Most new electric appliances -driers, stoves, etc. have a four prong plug. It wouldn't hurt now to run 4 wire. It costs more now but could save headaches later. Just my 2 cents.

[Jim Becker]

James brings up a good point. There are a few jurisdictions that require four wire service for 240v circuits because they generally are thinking about appliances, rather than 240v-only tools. (You just leave the neutral unconnected and capped off in the outlet box) You may have to run the 10/3 if that is the case. But you only "need" 10/2 for your 240v tools...

[Rollie Meyers]

The code for wiring 30 amp 220 Volt in Calif. is for 4 wire cable(one for both hots, a neutral, and a ground wire). Most new electric appliances -driers, stoves, etc. have a four prong plug. It wouldn't hurt now to run 4 wire. It costs more now but could save headaches later. Just my 2 cents.

That sounds like a inspectors whim, not code if the load does not require a neutral there is no requirement to supply one, The NEC has required 4 wire feeds to ranges & dryers since the 1996 NEC (250-60 then now 250.140). Unless one is bringing in cooking appliances to a shop in most cases a 2-conductor w/ ground cable will be code compliant.

[James Benson]

What a local electrician told me to do is to get a 4 wire plug. But don't use the "Neutral" lug. Wire the two hots and the ground only. Does the same thing and meets the local code(County's). Since they don't know what the end use will be, They require it.

[Rollie Meyers]

What a local electrician told me to do is to get a 4 wire plug. But don't use the "Neutral" lug. Wire the two hots and the ground only. Does the same thing and meets the local code(County's). Since they don't know what the end use will be, They require it.

As I said it was a inspectors whim then, absolutely not a code issue & they can't go w/ "What if", they need to cite the CEC California Electrical Code which is the NEC.Currently CA is using the 2005 NEC.

[Jim Becker]

Rollie, my understanding is that local jurisdictions can require "more" than code if they put it in ordinances, so it may not just be an inspector's whim if they insist on 4 wire, even though the intended use will not require 120v. Our township has done that with some plumbing things, for example.