230V Outlet Installation

[Peter Meacham]

I need to install a surface mount outlet box to power my recently purchased used Delta 36-812 Unisaw.

Details:

- Outlet will be wall mounted indoors about 10' from main panel box.
- I want to use the Electric Dryer 30 Amp circuit breaker (currently unused). I could change the breaker to 20 Amp if necessary.
- The molded plug on the Unisaw has two horizontal blades and a round ground pin.
- The Unisaw data plate says it uses 12.4 Amps at 230V, single phase.
- I purchased a NEMA 6-20R (20A-250V) single outlet from Home Depot which has two live and one ground connectors.
- I was going to run flexible conduit from the panel box to the outlet.

My questions are: Is that the correct outlet to use?
What wire do I need? (I'm thinking Red, Black and Green, 12 gage.


Thanks, Pete

[Mike Archambeau]

check this out: http://www.csgnetwork.com/wiresizecalc.html

it will guide you on the wire size.

And this for plugs and outlets (males and females): http://www.google.com/imglanding?q=2...jKaksM&start=0

[Peter Meacham]

Thanks for those links Mike -

So, it looks like I am OK using the outlet I purchased and 12 gage wire (I have some), but it is White/Black/Green - anyone know is it is code correct to use those three colors instead of the Red/Black/Green?

[Prashun Patel]

This from an electrician friend (take with grain of salt as I - not an electrician - am relaying):

You cannot use 12ga wire with a 30A breaker. You need a 20a breaker or 10ga wire. 10ga might be harder to work with.

While not ideal, the colors of the wire don't matter, as long as they're properly marked for hot and neutral.

The breaker should be rated to the equipment and the wire and the receptacle. If you are using a 30a breaker, you need 10ga wire, and a receptacle that can at least handle a pass-through of 30a.

The risk to your equipment of oversizing the breaker is that if the motor bogs down, it might not trip and you risk burning the motor out.

My electrician friend convinced me to size mine to 12ga / 20A.

[Peter Meacham]

Shawn

Thanks for the reply.

I am going to change the breaker to 20A and use my White/black/green 12 gage wire to go the 15 feet or so from the main panel box to the outlet that I am installing.

I will paint the ends of the white conductor a red color to signify it as a hot conductor (along with the black conductor).

I think that will be OK unless anyone else has any input.

Thanks, Pete

[Dan Friedrichs]

You've got it right. Typically people will scribble on the end of the white wire with a Sharpie, or wrap a piece of black tape around it.

[Don Jarvie]

Sounds good. Just find the plug that matches the outlet.

Just an FYI, the 250V plug has the prongs configured different than the 20A-125V plug. I learned this with 2 trips to HD.

Double check the motor unless you did it yourself to make sure the black and white from the cord are connected to the 2 leads in the motor. You would be surprised how some people wire the green ans one of the hot. If if happen to have the green as a hot the motor will run but just on 1 leg (120 out of 240) since both are hot.

[Milind Patil]

Fully agree with Shawn. Your wire must be rated at or above the circuit breaker, otherwise you run risk of wires overheating (read fire hazard) in the event of overload. For 20amp breaker with 12AWG would be a good choice. Use 12/2 NM-B wire (available at HomeDepot, Lowes). There is no neutral in 220v circuit. Just two live wires and one bare ground wire. So total three wires in single 12/2 NM-B cable. Thats it !

You don't need to use conduit if unless you really want. You can fish the wire inside the wall (this is more elegant approach).

[Peter Meacham]

Thanks for the additional inputs, all good advice and I should get the job done this afternoon.