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BobRankin 10-20-2007 10:02 AM

Help on installing a 220v outlet
Hi, I have a 220v woodworking tool in my garage and would like to add a 220v outlet as there's only a 110v outlet there. My garage sits right above my fuse box so I'm thinking I could lay the cable from there to my fuse box and possibly buy the parts at home depot so I can ask someone who knows that their doing to make the final connections and verify it's up to code.

Where can you buy extra fuse panel switches? On mine I have 2 spare slots for 2 more. Some have metal clips joining 2 15 amp switches. I have a Home Depot across the street but I didn't see anything but those old screw in glass ones.

If anyone could let me know what guage wire would be okay for a normal 220v outlet (not a 220v/110v mixed like an oven) I'd like to do some of the dirty work and get the parts ready. The actual outlet is only $10.

jproffer 10-20-2007 10:26 AM

Wire guage depends on amperage. Look at the instructions or the info. plate on the tool. Did the instructions say that the tool wasn't "220/110 mixed"? How do you know that? If that is the case, and if the rated amperage is less than 30, you can use 10-2 NM.

Find out all the info needed ( the tool really "clean" 220 - no 110 needed) and post back.

J. V. 10-20-2007 11:20 AM

That does not look like a fuse panel to me. It's a breaker panel.
Just note the panel manufacturer name and go across the street and get a two pole breaker rated at the amps of the tool nameplate.
Purchase the correct size wire as per the amps, located on the tool nameplate.

Do not count on the salesperson at HD to give you the correct information everytime. EVER! Some are quite good, but that would be an exception.

Is the existing 120 volt recept box fed with conduit or cable? If it's conduit you will be able to pull the new wires (if existing are to small)) into the same conduit. Unless your tool current dictates bigger wire than allowed in the conduit and box.*

Check all this out, and if you need more assistance let us know.
This is a simple project. But do it right.

BobRankin 10-20-2007 11:50 AM

One tool I'll be using is just 220V only, it's a dust collector.
Motor: 2HP, 220V 60Hz
The tool store said it's 220v 9a so a 15 amp breaker should be ok.

Another tool I might get you can either buy the 110v version or the 230 volt version:
Amps 15 / 7.5
Volts 115 / 230
Hertz 60

Mike Swearingen 10-20-2007 12:25 PM

I'm not a pro electrician, so wait for their confirmation, but I think that you can go with a 30 amp double breaker with 10/2-with-ground wiring to do what you want to do.
There is no neutral with 220v, so you will need to connect both the black and white wires to the breaker (mark the end of the white wire with black tape on both ends) and conenct the bare gound wire to the ground buss in the panel (see where all the other bare wires are connected).
This is very easy and you can DIY. First, of course, you have to turn OFF the main breaker, but be aware that the two 120v legs above the main breaker are still HOT and will kill you if you touch them.
In fact, you need an electrical tester to test the panel after you turn it off to make sure that the main breaker in fact turned it off.
Good Luck!

BobRankin 10-20-2007 03:52 PM

With your help and the walkthrough I found online (normal circuit breaker only though) I think I can try it. I'll use my volt meter to make sure there's no current.

What should I be getting to install the xx/2 220v circuit breaker if I'm just using a dust collector, table saw or both at once?:
pair of 15a or
pair of 20a, 30a?

I'm guessing a double 15a but I'm not sure by having them clipped together they would add together to make 30 or if one of the leads gets >15a it would trip them both off.
If it trips at 15amps and my dust collector is only 9a is that risky for my machine?

Lastly, is there anything wrong with going with a thicker gauge wire than what is required? What if I went with 10 gauge for my double 15a circuit?

Andy in ATL 10-20-2007 05:50 PM

Definitely use 10 awg so when you find that you need a bigger breaker you will be ok up to 30A.

Mike Swearingen 10-20-2007 07:05 PM

As far as I'm concerned, there no such thing as "too large wire" on a just may be a little more expensive initially. When I built my home back in 1977, I did not use anything smaller than 12g anywhere in the house, although I knew that 14g would have been just fine on many of the 15 amp lighting circuits. All of my receptacle circuits are 20 amp.
I'm still with the double 30 amp breaker (NOT two 15 amp single pole breakers) with 10g/wg for what you want to do.
Listen to the great pros here for their opinions (not just me, because I'm not one.)

BobRankin 10-21-2007 12:09 AM

Would bad things happen running a single outlet for 15 feet direct from the breaker with a pair of 15a breakers using 14 gauge wire? The rest of my house uses 14 gauge wire.
The 220v outlets I saw at home depot all were rated 15a only. Nothing higher for those. Would using anything better than 14 gauge help since the outlet connection would bottleneck the run? The dust collector is 9a and since it's a single outlet nothing more would be used at the same time.

Andy in ATL 10-21-2007 06:08 AM

Simply put, no, bad things wouldn't happen. I would encourage not to use a pair of fifteen amp breakers with a handle tie, but instead use a double pole fifteen amp breaker. At the distance you are running 14 AWG would be fine.

Stubbie 10-21-2007 10:24 AM

You can use a double pole breaker with common trip as Andy has stated for single phase multiwire line to line 240 volt loads so as to disconnect both ungrounded conductors.....NEC 240.20(B)(2). This is a code requirement not a choice. A double pole breaker isn't very expensive. This requirement pretty much eliminates you from an incorrect installation like having the breakers configured such that you cannot handle tie them.

J. V. 10-21-2007 10:35 AM

Bob, if you can't find a 220 volt receptacle at 30 amps it is because they are usually rated 250 volts at 30 amp.
Google (search web) "Nema Standard Plugs and receptacles" you will find a chart that shows you the receptacles, their configuration, style, voltage and current.

Use a two pole breaker, not two 30 amp single poles tied together. Does that make sense to you?

As a DIY'er I recommend that you always go up on size not down on electrical distribution installations.

I agree with the above statements regarding using 30 amp #10 AWG wire.
You can also tap the circuit in the box and add your 120 volt outlet if you need one. But, you need 4 wires for this.
2 - hots #10
1 - neutral #10
1 - ground #12 green in color or bare cooper conductor. Example: 10/3 with ground.

Simply splice one hot, use the neutral and connect all grounds for 120 volt.
Just remember if the breaker is 30 amp you CANNOT use wire smaller than #10. You might want to look at splicing options. The best connection possible.

Stubbie, Can you show him the picture of the splice you presented in a recent forum? Insulated compression type.

BobRankin 10-21-2007 10:54 AM

The breaker I got was 15 amp 2 pole, not the ones with the clip or metal joiner piece.

Stubbie 10-22-2007 02:20 AM

Sorry, I'm not following what is going on here. So I need everyone to clear me up.....:)

1.) Where are we getting this 30 amp branch circuit from?

2.) What are the electrical requirements for the table saw?

3.) How do we know we need line to line and line to neutral loads on the same branch circuit?

4.) If we do need #3 and a 30 amp double pole breaker how we gonna connect a cord and plug table saw (that we know nothing about) to a 30 amp rated branch circuit and how we gonna connect a 9 amp 230 volt cord and plug dust collector to a 30 amp branch circuit?

5.) Where are we getting 30 amp receptacles from?

This is what I know....We have a table saw of unknown electrical requirements, we have a 9 amp 230 volt cord and plug dust collector. He wants to use the remaining 2 spaces in his main panel to get a 230 volt circuit to his dust collector. So I ask again where we getting this... just put in 10 awg so you have 30 amp capability? I am assuming this is coming from the combined possible load requirements of the table saw and dust collector and assuming they are on the same branch circuit. Take into consideration that these tools are not going to have 30 amp plugs. It would appear the DC has a 15 amp plug and we don't know about the saw. Look at table 210.24 and tell me if you see any problem in doing this? Specifically the required receptacle rating for 30 amps.


BobRankin 10-22-2007 06:48 AM

The table saw is 230v 7.5 amps or possibly 230v 12 amps depending on which I get. I only got a single outlet plug so only one would run at the same time.
I ended up running 14 gauge wire to a bi pole 15 amp breaker, no neutral with ground since I'll never use it for anything else. It's 15 feet of cable to the panel.
I was asking at the store if I wanted to run both appliances at once and getting a dual outlet but I didn't know you would add the amp of appliances together.
1) For the single outlet to run the 9amp dust collector OR the 7.5 or 12 amp table saw can you tell me if what I did was ok?

2) If I wanted to go back and put in a dual outlet to run both machines at the same time could you tell me (new question for the thread) what I'd need to do to safely handle the 2x 230 machines together? 10 gauge wire + 30 amp breaker maybe? Or two different cable runs to different breakers?

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