View Full Version : Wiring up a 220 outlet.

06-09-2007, 12:23 PM
OK - I have wired soo many 110 outlets I can do that with a blindfold on.

I need to install a 220 outlet for my router.

It has a plug with 3 prongs. I looked at the wiring I the plug. There is one white, one black and a ground. I looked in the control panel in the machine. The Black and White are connected to a circuit board.

I went to Lowes. I got a 30 amp breaker and a recepticle. The recepticle has a screw for black, and one for white and one for ground.

So, the breaker goes in the breaker box. I have wire -- 10-2 with ground. White wire, black wire and ground.

In the breaker box (subpanel) Where do I make the connections.

White and Black to hots on breaker? Is there a polarity?

Ground to ground? In my subpanel, the ground and the neutral are seperated. Not connected together, like in the main panel.

Does the nuetral get used anywhere in this circuit?

06-09-2007, 12:56 PM
You need two hots and a neutral. The single neutral carries the juice back for both of the hots. I think that some folks will use the ground as the neutral, but not a good thing to do.

06-09-2007, 02:00 PM
Yer suppose to use 10/3 for 220v...3 insulated wires and a bare ground wire. Black and Red would be the power wires, green and bare wire grounds. Since you are using 10/2 you would wire it up black on one side of the double pole breaker and white on the other pole. The bare wire to ground. Like Jerry said, you aren't suppose to do this...but being a redneck that I am, I've done it before.

You're best bet would be to get 10/3 wire. Yeah, I know, at the moment, wire isn't cheap, but it's cheaper then buying a new router!

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I've cut it three times and it's still too short!"

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06-09-2007, 02:21 PM
Ya gotta' wire the black & the white to two adjacent FULL-THICKNESS (not half-height) breakers. Either to either, no probs.

Now... before you do that, though, ya gotta' take some red or orange or black electrical tape & fully wrap that white wire. Do it at BOTH ENDS, so you can't see any white anywhere.

That way nobody ever thinks that 2nd hot is "dead" neutral & get their shorts bit.

I like to use red, myself. Makes it look like a 2nd leg that way.

-- Tim --

...and having a FIELD DAY...

06-09-2007, 02:55 PM
Leo with 220 volt circuit you have two hot (110) and a ground no neutral. Sub panels aren't suppose to have the neutral grounded, all neutral are grounded in the main box only.

06-09-2007, 02:59 PM
So then how would YOU wire this circuit?

I can snap a pic of the panel if that would help.

06-09-2007, 03:31 PM
Funny... I have done this a lot (read post about moving ;) ) and I am still nervous telling you how to do this online.... http://www.woodhelp.com/uhoh%20rolling%20eyes%20smiley.gif

In your breaker box you need to have a breaker that is "set up" for 220v... there is 2 terminal screws on the breaker... both are HOT - I would hook the black and white wires to this, marking the white wire with black electrical tape on each end so I knew it was now a hot wire... and the ground I would wire up to the neutral bar in your breaker box...

Where the hell is Sonny anyhoo??

I will go email him... so we don't kill ya http://www.woodhelp.com/Cheesy%20Smiley.gif

06-09-2007, 03:34 PM
That is what I was thinking too - but it just doesn't sound right.

SONNY ??????

Where are you when we need you.

06-09-2007, 04:43 PM
Here's the deal... right now I have the bandsaw and tablesaw both wired just like I described... and they run :)

You get 2 hots and one neutral with a 3 wire 220v run... with a 4 wire you add a ground...

At least that's my understanding... and what I do... did... will do again :)

Wood Rookie
06-09-2007, 05:21 PM
Can't you just throw all your live wires into a bucket of water? That would connect them. (The REAL redneck way.)

Sorry I have nothing constructive to add to this...


06-09-2007, 05:22 PM
I will let you know in about a half hour.

If you trace the wiring back to the main panel - the white neutral and ground do come together. In reality they are hooked together.

So I am going to hook the ground wire to the white neutral bar in the sub panel.

06-09-2007, 10:11 PM
You're doing it right, Leo. Inside the breaker panel, you may have ONE or you may have TWO ground bars. If you have TWO, they're electrically identical to each other... and completely hard-connected. If you have ONE, you have one.

Either way, electrically, you have ONE.

It's possible that the machine you're connecting to wants 120 divided out from the 240. In that case, you'll have return current going back up the third wire (neutral or ground) to the breaker panel. That can make for discomfort if you assume that the bare wire is just a dead protective ground with no current on it, ever.

If you disconnect a NEUTRAL from the breaker panel while the equipment is "live", the wire will be "hot" (from return current) in your hand.

If you disconnect a protective GROUND from the panel with the equipment "live", that ground is "dead" because it's only protective - it only connects to the chassis, frame, or case of the equipment.

It's best to use an INSULATED wire to carry that potentially-"live" neutral (or ground, whichever it is) back to the panel, instead of a bare wire.

BUT... you're very probably OK just as you're doing it.

A three-wire 240V plug is nearly exact equivalent to a two-wire 120V plug... likewise receptacles & wiring. It's assumed that there's no protective ground, but there is a neutral. A four-wire 240V plug is like a three-wire 120V plug - you've got hot(s), neutral, and ground.

Make sense?

-- Tim --

...and having a FIELD DAY...

06-09-2007, 10:26 PM
I gotta ask a dumb question. Why is there a twistlock plug on the machine? That's not factory is it?

We use hundreds of twistlock plugs and receptacles at work, but we use them for a much different reason. It is imperative that our tools can NOT become grounded, so ungrounded twistlocks are installed on everything used in this certain area (we do not connect the green wire). That way some dumbo won't be able to plug a grounded tool into the power outlet and kill himself on the spot (I work in a strange environment with massive DC voltages).

If your machine is truly 220 volt, you are on the right track. You should have purchased a two pole (looks like two breakers riveted together with a common bar across the handles) circuit breaker. Using two single pole circuit breakers is against the National Electrical Code because a double pole breaker is more than just two breakers stuck together. A double pole breaker has a common trip link for both poles internally. This ensures that if a fault or overload occurs, BOTH circuits will be broken.

Anyway, It takes only two wires and a ground for your circuit to function. Both insulated conductors are tied to the circuit breaker. And as Tim alluded, it is a smart idea to wrap the white with black tape so it cannot be mistaken for a neutral wire. Itís not mandatory, but it is smart.

Now to the hard part. The ground wire, bare or not, should be attached to the GROUND bus, or bar, NOT THE NEUTRAL BUS. I emphasize this because, even though in your case the neutral and ground bus are tied together (the term is bonded), that is not always the case. The neutral bus in my both garage and house panels is NOT bonded to the grounding bus. My grounding buss ties directly to earth ground, simply meaning the ground rod driven outside below my meter socket (actually two rods). My neutral bus is tied to the power companyís transformer neutral, and wonít be grounded until it gets back to the power company grounding point, wherever that may be. In your case, Leo, and in most older homes, both the ground and neutral are tied together (bonded). However, newer homes, at least in this part of the country, are mandated to separate the two. This is a fairly new power company requirement, within the last ten years. They will not hook up a new service to a bonded panel.

The only reason Iím going on about this is so you all will not think that these posts are a blanket instruction on grounding your equipment. Please check carefully where you connect a ground wire. Grounding can save your life- the lack of it can kill you.

06-09-2007, 10:38 PM
NICE writeup!

Only one thing... the NEC does mandate that a white-insulated wire used as a supply wire MUST be colored to indicate that fact. Electrical tape is their suggested way of accomplishing that coloration. As white is out of the question, green indicates protective ground, and yellow indicates 24VAC, there aren't a lot of colors left... and red is very commonly used for second-purpose legs.

-- Tim --

...and having a FIELD DAY...

06-09-2007, 11:11 PM
On 220volt the ground is ground. As chassie ground. You can run a 220 volt circuit on two wires, the ground is for protection. Some motors such as water well pumps operate with two wires. It is rather confusing but you are ok to use the bare wire in your circuit as ground. The reason that the neutral in a sub panel isn't connected to ground is for safety, if you connect it to ground it will still work. If a wire return to the main is broken there is a possibility that the metal of the sub panel will be hot.

06-10-2007, 12:52 AM
Just for a second.


The plug is a 30 Amp plug.

The cable on the plug is what one would use for either a 115 volt or 230 volt machine.

What I did not see is any indication of the actual voltage requirements for the machine.

If the machine is TRUELY a 230 volt machine, the plug wiring is not the best in color code terminology, but it is acceptable and it will work. (BTW - Both my dust collector and table saw are wired in a similar manner and both are 230 Volt machines. The table saw used a wh, bk, gr cable for the power cord.)

If the machine is truely 230 volts, the white and black are used as the hot leads and the green is AC Safety ground. For this wire your outlet as Tim suggests, 10/2 w/ ground and wrap the white wire with red or black tape so that the wire becomes a "black color code" wire. (I prefer conduit with red, black and green wires.) Connect the blacks to the gold terminals of your outlet. Connect the ground (or green) wire to the green terminal of the outlet. In the circuit panel, connect the ground to the ground bus. Connect your black wires to your double wide breaker and snap into place.

The thing that confuses everyone is that it is NOT necessary for a 230 volt machine to have a neutral wire in the circuit. My table saw outlet has three wires, phase a, phase b and ground. The plug looks like a smiley face with its eyes closed, has only three prongs, and no neutral.

06-10-2007, 10:40 AM
Tim, you may have taught me something this morning. Thank you.

I canít seem to locate the code requirement for residential conductors concerning current carrying conductor identification (specifically white), though my code book is a few years old. In the old days, 12-2 romex was used throughout the home, and heating circuits and switch legs were not normally re-marked. It was a given that when you pulled a switch out of the wall, the black was the hot and the white was the return to the fixture. Iíll keep looking through some of the driest reading book on the planet though. The code changes faster than Mario Andretti can drive.

It has been mandated as long as I remember by NEC that earth ground (equipment ground) wires be clearly marked. Those conductors, if not either green or bare, must be identified by green colored tape, or a tag designating the conductor function. Like you, I use green tape when needed. I usually go one step further and wrap a Brady tag indicating the circuit number on all my wires, including neutrals. Much easier to modify later without having to trace.

The bonding issue I discussed above has tripped up more than one good electrician, including myself several years back. I installed a 200 amp garage service for a friend and, as I had done for years, I bonded the neutral bus and ground bus together with the green bonding screw that comes with the panel guts. The power company inspector inspected the installation, and, after having me remove the bonding screw gave me the Okey- Dokey sticker. The PC boys were out the next day to hook it up to their power.

I rarely give electrical advice over the internet, mainly because most people donít read half of the post, canít understand what they read, or dispute what has been written. But this was a good opportunity to let at least a few people know that instructions for one case may not fit the next case. In Leoís case, he traced the service out and knows that the two busses are bonded. The next person that searches the archives may think that itís standard to install the equipment ground onto the neutral bus, when it is not. Grounding is much more important than the power wiring. Electricity will ALWAYS find the easiest path to get to the earth. ALWAYS. Ever been shocked? You were lucky. You just happened to be very poor path to the earth. Had you been the EASIEST way for the current to get to the earth, you would be dead. Common 110 volt house current kills more people than all other voltages combined.

Just reiterating the importance of correct electrical installation. I have seen firsthand the aftermath of a screw up.

06-10-2007, 01:30 PM
OK heres what i did

I personally wired the subpanel when I wired the addition in 2002.

There is a neutral bar and a separate ground bar. The ground bar is attached directly to the box.

Back in the MAIN panel in the house the green ground and the white neutral that feed the subpanel, and connected to the same strip. Electrically, they are connected together.

For the machine - yes it is truly 230V, 15A

At the subpanel:

I used a 30 amp 220 Square D breaker.

I ran a 4' piece of 10-2 wire from the panel to the receptical.
Ground connected to the ground bar in the panel.
Black and White connected to the breaker.

At the receptical - ground to ground, black and white to the other screws.

IN the machine - the ground is connected to the case.

It works - to me that is what matters - it works.

As for the plug - I don't know if it came from the factory that way. All I know is that "I" got the machine that way.

06-10-2007, 01:35 PM
>If the machine is truely 230 volts, the white and black are
>used as the hot leads and the green is AC Safety ground. For
>this wire your outlet as Tim suggests, 10/2 w/ ground and
>wrap the white wire with red or black tape so that the wire
>becomes a "black color code" wire.

That is what I did - except for wrapping the white with blace tape.

>The thing that confuses everyone is that it is NOT necessary
>for a 230 volt machine to have a neutral wire in the

That is what was confusing me. I looked at my main panel and noticed that my well pump only had two hot leads going to it. As near as I could tell that was the same with the dryer. So I figured I would do the same with my machine. It worked.

06-10-2007, 05:04 PM
"It works - to me that is what matters - it works"

That's how I judge these things... if it works, it must be right :)

Glad ya got it going!

06-10-2007, 05:50 PM
Ya done good! As long as it's safe, and from your detailed description, it is, all is well again in the kingdom of Woodworking .com.

06-10-2007, 08:25 PM
Leo you did it right. Marking the white wire as a hot wire is a good idea. Good luck with your machine, looks great and I belive you can get it going. Keep us posted.

06-10-2007, 10:07 PM
Even if you use a magic marker, please mark the white wire either red or black. Twenty years from now, after you've sold the house and someone goes into the circuit, they will immediately KNOW that the marked white wire is hot. The marking could save somebody's life.

06-02-2010, 09:30 AM
I don't have a problem wiring it with 10/3


The machine is NOT wired that way.

The plug on the machine has a black, a white, and a ground. Nothing else.

I am not a redneck and I don't like doing it wrong - but I don't think I have an option here. How do I rewire the machine?

If I wired the recepticle differently, like using a neutral - How then would I get all that into the machine?

Wait a minute - I am going to snap a few pics. Be right back. tick tick tick tick tick tick tick tick tick .................................................. ........

Just gotta crop and fix em up .................................................

OK - I am back

There are three pics of the plug on the machine

There are two pics of the recptical I bought at Lowes

Am I going about this right or all wrong?

What are my options?