[Tony3141]

Are there any outlets that take a common household plug which are designed for 10/2 wire and 110V? I've found some outlets that are good for 20A, but not 30A. Would the 20A receptacles work with 10/2 wire?

[tkrussell]

Common household outlets are limited to 15 and 20 amp. Any common household appliance is no more than 20 amps.

There are some appliances that may need 30 amp, such as a window air conditioner, or a dryer, and there are special outlets for those.

Why do you ask? Very odd question.

[stanfortyman]

You can use 10/2, but as TK says, you CANNOT use more than a 20A breaker.

If you have some 10/2 and are looking to use it up you'll be sorry. That is a PIA to work with in small boxes and you have to be real careful with box fill.

[Tony3141]

I was rewiring part of my shop and at some point I may want to have a 240V 30A circuit. So I thought I would run 10/2 wire, use it as 110V circuit until I get tools that are 240V. Just trying to save some time and effort later if I want to upgrade. It sounds like I could do this and then use a 20A circuit breaker with 20A outlets. The only trouble comes in fitting the wires in the boxes.

[tkrussell]

OK, since the #10 wire will not connect to any 15 or 20 amp device, what you can do is pigtail short pieces of #12 wire onto the #10 wire at each outlet box, and then connect the #12 wire onto the device.

As Stan mentions, be sure the outlet box is large enough to handle the #10 wire, device and pigtails.

Converting over to 30 amp 240 volt circuits will be easy by changing the breakers and devices to 30 amp.

I do have to say, and not just with this question, but many others, if posters would just add the detail in the original question, would make answering so much more easier and quicker, than all of this back and forth.

[rtw_travel]

I was rewiring part of my shop and at some point I may want to have a 240V 30A circuit.

Just to complicate your decision, you may need 10/3 wire, not 10/2. It depends on what you end up wanting to do.

If it was me, I'd go a bit bigger gauge, and then have a small sub-panel in the shop. Then you can do whatever you want in the future.

[stanfortyman]

Just to complicate your decision, you may need 10/3 wire,

Why would he need 10/3 ?

[Stratmando]

I'm guessing the 10-3 would allow a second circuit with just 1 extra wire, or it could be a switchleg for lights?

[rtw_travel]

Why would he need 10/3 ?

I can think of a number of reasons:
- don't twistlocks require 4 wires?
- There are a bunch of power distribution centres/ extension cords that would take a 240V twistlock and separate it into a number of 120VAC outlets (no subpanel required).
- depending on the location of his toolroom, it may be a better spot for a backup generator (with appropriate transfer switches etc).

The bottom line is that you get a bit more flexibility.

[stanfortyman]

My comments:

- don't twistlocks require 4 wires? NO, not always. A twistlock is no different than any other receptacle. There are about 100 different configurations.

- There are a bunch of power distribution centres/ extension cords that would take a 240V twistlock and separate it into a number of 120VAC outlets (no subpanel required). Why would he need this in a shop he is just now re-wiring? That is a job site item.

- depending on the location of his toolroom, it may be a better spot for a backup generator (with appropriate transfer switches etc). In the middle of a shop? Also, how would this help?

He specifically states he may want a 30A/240v circuit in the future for tools. 10/3, while it maybe would give some amount of flexibility later, is more just a waste of material.

[rtw_travel]

In most cases, we should not assume that we know exactly what the opening poster needs, because they hardly ever give full information. I have always thought our role at askme was to give enough information defining plausible situations, so that they can make up their own mind based on their own circumstances.

Yes, if he absolutely guarantees that he will only need a single circuit 8/2, then by all means he should install 8/2. If he is not exactly sure what he might need, then we should give him more information so he can make a better decision.

Stanfortyman - neither you nor I were wrong in our answers. I am just annoyed that you wrote mine off as if yours was the only answer that could be right.

Is 8/3 a waste of material? Perhaps, but it is more flexible for unknown future needs. 8/3 will have one extra wire if you end up only needing 8/2. However, 8/2 is scrap if you end up needing anything other than 3 wire 220V circuit, or a single circuit 120 V. Do you want to give up this flexiblity to save $0.50/foot?