Supply Wire Size for 220 circuits

[652plus2]

Hey guys,

I'm re-wiring my old garage - I added a 100amp subpanel and now I'm laying out all of the circuits. I want to run 4 dedicated 220 lines for my 6hp 80 gallon compressor, my electric oven for powdercoating, a mini-split hvac and a 220 mig welder. None of the runs will be more than 25' long. I know just enough about electricity to get myself in trouble. What size supply wire should I be using? The more I read, the more I think I should ask someone who knows. Can you help?

 

[Charles (in GA)]

Its 240 volt, not 220. You need to look on the data plates of each item and find out the amp draw of the equipment. The welder manual should tell you what to use on it.

Charles

 

[Rosco]

Charles is correct. I ran 10/3 for my compressor, 8/3 for my welder, 12/3 for future mini-split and 6/3 for a free standing stove. It will all depend on the current draw from the appliance or tool. I always run larger just in case and then breaker it down.

 

[652plus2]

Its 240 volt, not 220.
Charles

See what I mean...I know just enough to get myself into trouble. 220, 221...whatever it takes.

Thanks so much for your help. Lets say I haven't chosen a welder yet, ('cause I haven't) but I want to run my wires while I have the walls open. I'm a hobbyist restorer working mainly with sheetmetal, but I want a to step up from a 110 welder. Is there a wire size that I will be safe with without knowing exactly what machine I'm buying and without going wild?

 

[Rosco]

Thats why I ran 8/3. I Might not need the extra wire or guage but I do not want to pull it out in the future.........I will just match my breaker size to the welder.

 

[sdowney717]

I used 8/2 on the welder.
Craftsman AC arc welder with 3 prong plug is only 240 volt circuit.
Inspector approved!

 

[Norcal]

I used 8/2 on the welder.
Craftsman AC arc welder with 3 prong plug is only 240 volt circuit.
Inspector approved!

That because a neutral is not needed & a waste of money for a 240V circuit.

 

[sdowney717]

sure would have been!

 

[652plus2]

Thanks for the help on this, guys. I don't post much, but I read here every day. This is a great forum.

 

[gatchel]

220, 221...whatever it takes.

Great movie!

 

[ForceFed70]

Well, to run a kitchen oven you need a 40A circuit which means 8/3 wire.

 

[Norcal]

Well, to run a kitchen oven you need a 40A circuit which means 8/3 wire.

Depends on the oven, the nameplate tells all but how often is someone gonna install a oven in the shop? not unheard of but a rare thing.

 

[ForceFed70]

Depends on the oven, the nameplate tells all but how often is someone gonna install a oven in the shop? not unheard of but a rare thing.

Well, he did mention electric oven for powdercoating in the original post.

Standard kitchen oven requires a 40A circuit. If he's using a specialty oven, then yeah... he'd need to know the reccomended circuit size.

 

[Norcal]

Well, he did mention electric oven for powdercoating in the original post.

Standard kitchen oven requires a 40A circuit. If he's using a specialty oven, then yeah... he'd need to know the reccomended circuit size.

30A is not unheard of for a oven....

 

[652plus2]

Yeah, it's just a standard kitchen oven I bought for powdercoating, so I'll go with a 40A breaker and 8/3 wire. You can see some of the old set-up in my "pre-divorce garage" below. Now I'm trying to recreate that garage at my new residence. It probably sounds like I'm asking stupid questions, but I don't actually have my compressor, lift, oven, etc with me right now, so I can't just look to see what their requirements are. Everything was stashed in storage in another State when I moved out.

My new garage may be much smaller, but I'm far happier in it...trust me...

 

[Norcal]

A freestanding range will require a min of a 40A* circuit, plus it's required to be 4-wire as grounding the frame of a appliance to the neutral is not allowed in new installations anymore, (Since the adoption of the 1996 NEC).

*Nameplate rating will determine the required circuit.

 

[ForceFed70]

A freestanding range will require a min of a 40A* circuit, plus it's required to be 4-wire as grounding the frame of a appliance to the neutral is not allowed in new installations anymore, (Since the adoption of the 1996 NEC).

*Nameplate rating will determine the required circuit.

1 post you are saying it's not unheard of to use a 30A circuit, the next you are saying it's 40A minimum. Yes, yes.. look at the nameplate rating. But let me assure you that you're not going to find a regular 30" kitchen oven that requires larger than a 40A circuit. Nobody builds them because nobody has the wiring in their kitchen.

The OP already said that he'll use 8/3 wire.

 

[Norcal]

ForceFed70: A oven and a range are 2 different things...........

 

[marslawn]

I just read your post and I can comment on what I know. I have helped out an electrician for some extra work the last years. I put in 6/3 wire for my welder. If I were you I would buy a roll of 6/3 and use it for you welder and oven. The new ranges are almost all 50amp. You can always use a smaller 40amp plug with 6/3 wire. The compressor can be 10/2. I can't speak to your split hvac, but if you have enough 6 wire I would use that. Just remember when you go to install all these items that you use the correct breaker size for each item, this way your wire is protected.

 

[fflintstone]

My new garage may be much smaller, but I'm far happier in it...trust me...

my garage space grew by leaps and bounds when I got divorced.
I was much much happier.

I used to not have a clue with automotive electrical. I met a girl that crawled into the engine bay of my CJ8 and showed me how to use a multimeter. about 12 years latter she became wife2.0......

 

[drcheap]

I know just enough about electricity to get myself in trouble.

Here's a tip to help you get beyond that troubling level of knowledge...

The size (gauge) of the wire needed is not really dependent on the voltage. 120V, 220V, 240V, they all use the same wire. Typically said wire is rated for about 600V or so, and will more than suffice for any wiring job you will ever encounter in your house.

What does affect the size of the wire is the current you need to supply to the load. A 40A circuit is going to need much larger wire than 15A circuit, regardless of the voltage.

The major difference between using 120V vs. 240V will be that there are two hot conductors vs. a hot and neutral. Or there could be two hots and a neutral, but I'll leave the details on that topic as a Googling excercise.