what size wire to run for 220V??

[Ken Fitzgerald]

My main reason was to eliminate nuisance trips.

[NICK BARBOZA]

Ok i think im catching on... so in the panel with the 10/2 i will attach the white and black to the breaker, and the ground to the appropriate bar. with no "common" attached to it's bar. correct? and likewise on the receptical, white and black to the brass screws and ground to the green.

the rating on the motor is 15 amps. so i should still go with a 30 amp or will 20 suffice?

thanks for your patience with my in-experience,
Nick

[Dennis Peacock]

It would depend on the FLA of the motor, but assuming an overall efficiency of 80%, you're right on the ragged edge of maxing out a 20 amp circuit at 220 volts.

Yup....my feelings exactly.

[Tom Veatch]

...so in the panel with the 10/2 i will attach the white and black to the breaker, and the ground to the appropriate bar. with no "common" attached to it's bar. correct? and likewise on the receptical, white and black to the brass screws and ground to the green.

Correct. You should also permanently mark the white wire at the terminations with something to identify it as a "hot" wire - length of black heat shrink for example.

the rating on the motor is 15 amps. so i should still go with a 30 amp or will 20 suffice?

20 amps is sufficient for a 15 amp load.

[Dave MacArthur]

Nick--
You are researching what you need to do, and I commend you for going for it, and researching here.

HOWEVER--- you DEFINITELY need to buy a book on home electrical and read it before doing this, and if you don't feel 100% ready after that, hire an electrician.

You need a permit from the local authority to do the electrical work, usually before any work is done--a good plan with all info on it will usually get the permit, and they will inspect before you hook up power.
--failure to do this, or follow code in several areas of your question can lead to a fire, and absolutely to an insurance company denying coverage if that happens.

Again, kudos to you for investigating...but your questions on 220 needing 3 wires plus ground, and the 30 A for a 15 A motor really have me worried--no disrespect intended.

Here's my take on your situation:
1. If it's easy for you to run the wire (easy to add a 30A circuit later), then I'd go with 20A circuits, and I'd run them on 12 gauge wire with 2 conductors and a ground (12-2NM-B)
--the circuit breaker protects the WIRE
--the plugs must be correctly sized to the circuit breaker! Not the wire
--a circuit with a 30A CB MUST have all plugs be 30A NEMA plugs... this means you can't plug stuff into them without replacing their male plugs.


2. If running the wire is not easy, and/or you want to give yourself flexibility for future increased amp motors (5HP), or to possibly run some 110 plugs off one of your 220 circuits, AND the cost of the now-expensive copper wire is not a limfac, then I'd run 10-2 wire, protected with 20A CB and with 20A receptacles; and anywhere I thought I might want 110 option later, I'd run 10-3. You can look in a book later about running one of the hots from a 220 onto the neutral for 110 power on a 220 circuit, if it ever comes up.

--Downsides: 10-2 or 10-3 are more expensive
--10 gauge wire is much stiffer! and hard to pull
--you can't fit much 10 ga wire into conduit, forcing larger conduits or more of them if using them


Good luck! and read this:
http://www.selfhelpandmore.com/homew...rage/index.htm

[Rick Christopherson]

When I did my shop, I used 10/3 with grnd. for all 220 circuits. Cost was a bit more, but I can install anything with a 5hp motor AND I can pull a 110 line from that setup.

That would be a great concept if it weren't a code violation.

[Steven Wilson]

Nick, 12-2 will support a 20A circuit and will be just fine for your Jet (more than likely, you still need to look at the FLA on the motor when the machine arrives).

Having said that, 220v tools are like rabbits - they multiply quickly. Unless you have a big main panel that is sparsley populated I would take the opportunity to run a sub-panel (say 50-60A) for wiring up 220v machine circuits (keep your lighting on the main).

Having run a sub-panel I would then run conduit and pull THHN wire to wire circuits for individual 220v tools. If you do this and then need to upgrade later you don't have to tear into your walls just and conduit and/or pull new wire if you need to.

I'm not a fan of using 10ga for all of my wiring and then change breakers and plugs as needed. Doing so reduces the number of wires you can run in conduit (or run through boxes if you do that), isn't very ellegant (the next owner of your house will go Huh????), and is costly. Unless you know that you are likely to procure a 5HP machine in the next few years I would just wire the circuit appropriately (20A in your case most likely) and deal with any upgrades when the time comes.

[David G Baker]

I run #10 or larger to sub panels and drop smaller legs to my plugs. I have at least 5 or 6 sub panels, they don't cost that much and make things very convenient if you want or need to add more circuits.