110 upgradable to 220

[kolky]

Putting new electric in my garage and I’ve got a couple of spots where I am going to put dedicated 110 outlets for a fridge and air compressor.

As these would be dedicated 20A outlets, I started thinking that if I run them with 10ga, wire instead of 12ga and put them in a quad box, I could easily upgrade those outlets to 220 in the future if needed as long as I leave a breaker slot open next to each.

Does that sound reasonable or am I missing something?

 

[mike93lx]

Why would you need 10 to upgrade to 240v?

110/220 are pre-war Voltages. It's 120 and 240

Wire gauge determines current carrying capacity, not voltage capacity

 

[u2slow]

#12/20A/240v circuits are very useful in my shop. It's all my compressor and welder need.

 

[The Cobbler]

as noted, wire gauge doesn't determine voltage , it determines amps . a run of 14/2 is capable of feeding 240 but is limited to 15amps
what sort of amperage do you need for your 240 circuit?

 

[kolky]

Sorry should have stated 240.

I was thinking 10ga in case I needed to go up to 30A 240 and because I ended up getting some 10ga wire on Amazon a while back when they had it for $35 for 50ft. Some of the things I could see using that in the future would be an electric car charger, large compressor or welder.

 

[Terry D]

If you are running new electric, then you should have a panel large enough for future add on's. Run your 120 volt receptacles and run some for 240 volt receptacles now or down the road. The gauge of wire has nothing to do with voltage

 

[karoc]

Like my ole father inlaw us to say “ Better to have it,than to want it” 10 will give you more flexibility

 

[Jackfre]

I agree that you should build it for future growth and flexibility. Another consideration for you is what you are putting on your walls. I did 1/2” plywood with tech screws. When I added the solar last year it took me about 15 minutes to remove the two sections of wall necessary to access the interior of the wall and add the combiner panel, etc. It took about 15 minutes to close back up. I’m kinda slow and didn’t anticipate my needs properly. Being able to access the interior of the walls has really helped me out. With plywood prices where they are you may only do sections of the wall.

 

[jeepxj]

my vote is for #10 home runs.

 

[u2slow]

Most 15-20a devices won't take #10 so you have to pigtail it down.

Upsizing is never-ending. If you go #10, you'll get a machine that needs #8.

I wire in what I need when I actually need it. Saves a lot of money.

 

[rburke65]

OP....OMG...?...did you just say 110...220? I see already where the purist voltage gods have corrected you! You must be a real Neanderthal! Ha... Shame on you.

 

[mike93lx]

OP....OMG...?...did you just say 110...220? I see already where the purist voltage gods have corrected you! He must be a real Neanderthal! Shame on you.

Happy to do my part.

 

[American Locomotive]

I don't understand what that would get you? I'd just run a separate 240v circuit if you think you're going to install something in the future.

 

[alfredeneuman]

Run some flexible conduit through the walls, through the top plate, or both.
Then no matter what your needs in the future you'll be covered.

 

[u2slow]

What I did in my shop is run #12 MWBC's on a 2-pole breaker. Then wherever I have a box, I can wire a 120 or 240 receptacle as needed.

Doesn't work with gfci's of course, but I don't need or require them.

 

[alfredeneuman]

What I did in my shop is run #12 MWBC's on a 2-pole breaker.

What if you need a circuit larger than 20 amp?

 

[u2slow]

What if you need a circuit larger than 20 amp?

*Then* I would add a dedicated circuit later.

 

[hippie2cams]

When I built mine I had the electrician run all the basic wiring before insulating, then install surface mount box so addons could be run through conduit.

 

[Terry D]

When I built mine I had the electrician run all the basic wiring before insulating, then install surface mount box so addons could be run through conduit.

Yes, this exactly. If you are having finished walls, then run some flexible conduit from the panel to some surface mounted boxes. Then you can always add on to the boxes with conduit and pull in circuits later.

 

[Citation]

I get the idea but I think I would do it differently. For example, currently you have a 120V compressor but in the future you might need a bigger compressor. So the 10A wires that currently feed a standard 120V outlet could later be changed over to a 20A, 240V outlet (bigger compressor, welder, electric car charger etc). It could be handy but really if you think you might want a 240V outlet in the future, run the wire now even if you just wire it into a box with a cover plate. If you have the panel space, put in the breaker but leave it off with a tag or something. If you really can't just leave a 240V line terminating in a box in the wall then sure, use the 10G wire for this outlet. You could change it later.

 

[alfredeneuman]

Doesn't work with gfci's of course

There are 2 ways of protecting MWBCs.
You can install a 2 pole GFCI breaker or where you have 120V circuits install separate GFCI receptacles

 

[u2slow]

There are 2 ways of protecting MWBCs.
You can install a 2 pole GFCI breaker or where you have 120V circuits install separate GFCI receptacles

Agreed, I was thinking of the receptacles.

Regardless, I require neither one.

 

[nadogail]

110/120/125 ?, I am one of those Dinosaurs who is slowly adapting to the latest permutations of our version of the “English” language.

 

[Showkey]

110/120/125 ?, I am one of those Dinosaurs who is slowly adapting to the latest permutations of our version of the “English” language.

Thats because you have it wrong …..it’:

110/115/120

We have not up the ante to 125 yet.

 

[Walkers]

just make sure the wire feeding you sub panel is big enough. Why not put in a nema 6-50 outlet to feed a welder now. Also, get a compressor that will take the higher voltage and wire it that way for quieter start ups.

 

[alfredeneuman]

Also, get a compressor that will take the higher voltage and wire it that way for quieter start ups.

Please explain why the start ups would be quieter.

 

[Stuff]

Thats because you have it wrong …..it’:

110/115/120

We have not up the ante to 125 yet.

What about 117?

Receptacles show ratings of 125.

 

[Walkers]

Please explain why the start ups would be quieter.

Start ups are easier running the motor on higher voltage, there is less inrush current. On lower voltage when the compressor kicks on you get the typical lights dim, low growl of the motor, then it comes up to speed. With the higher voltage the motor just turn on.

 

[alfredeneuman]

Start ups are easier running the motor on higher voltage, there is less inrush current.

Isn't the total energy expended to start the motor the same?

 

[pattenp]

Start ups are easier running the motor on higher voltage, there is less inrush current. On lower voltage when the compressor kicks on you get the typical lights dim, low growl of the motor, then it comes up to speed. With the higher voltage the motor just turn on.

If properly wired for the load at the voltage used a duel voltage motor will start and run the same on 120V as on 240V. The issues you give are due to voltage drop from an inadequate supply and has nothing to do with 120V vs 240V in itself.

 

[Walkers]

I would have to disagree with you from my personal experience. A compressor plugged in at an outlet right at the SE running low voltage starts up the same as it does 300 feet away in my shop. Transformer is 50’ from SE. so unless you think the service cables or transformer are undersized (they are not) then I would say that the higher inrush current on the lower voltage wiring was responsible. YMMV.

 

[Walkers]

Isn't the total energy expended to start the motor the same?

You would think so, but every thing I have ever changed from 120 to 240 starts up faster and easier on 240 (Or are we up to 245-250 yet?)

 

[jeepxj]

You would think so, but every thing I have ever changed from 120 to 240 starts up faster and easier on 240 (Or are we up to 245-250 yet?)

I wonder if there is math to support that. i always thought you went 2XX volt to reduce wire size for same KW.

 

[pattenp]

I would have to disagree with you,...... I would say that the higher inrush current on the lower voltage wiring was responsible. YMMV.

That's what causes voltage drop which is what I was saying. The wiring is undersized to handle the inrush current. Just to generically say a motor runs better on 240V vs 120V without stating other mitigating variables is inaccurate.

 

[Walkers]

What I am saying is that plugged directly into the source it still does it, so is it really a mitigating factor? Or is it just the way it is?

 

[KenC]

A lot of dual voltage consumer grade compressors come with and undersized cord. That may be the limiting factor on 120v.

 

[Lassen Forge]

But wait, my current electrical line voltage is 113.31 ± .2%... anything else is WRONG and NOT IN AMERICA...

Because even though we ALL know what is meant by 110-220 or 120-240 or 117-234... we still have to show we are smarter than y'all...

 

[alfredeneuman]

Because even though we ALL know what is meant by 110-220 or 120-240 or 117-234

Of you ALL know why do you use the wrong terms? Typos?

 

[Lassen Forge]

Of you ALL know why do you use the wrong terms? Typos?

Huh? Speaking of typos...

 

[alfredeneuman]

Huh? Speaking of typos...

I'm not immune to typos. Are you?
Math is a big part of electricity. If you enter the wrong figures you'll get wrong results.
There has to be a standard.