12/2 or 10/2 -- 220 general purpose outlets

[Mark Welte]

Black tape is also acceptable--anything but white, green, blue, yellow, or orange, which all have particular uses.

D.

You would love my house then. They can all be hot. Makes any electrical work a practice in patience to determine what wire does what. I am in the process of getting them all up to code but it is time consuming. I see why there is a reason for the code.

[Bruce Wrenn]

Another vote for multi-wire branch circuits. 20 amp, two pole breaker, #12 wire and you can have two 120 circuits, and one 220 circuit at each location. If your local inspector requires that all 120 recpts be on a GFCI breaker, then just use recepticals down stream from 220 recpt.

[Van Huskey]

Dan, Steve already answered the isuue of the neutral current and why a double pole breaker is used.

I'm an Electrical Technologist and I think you'll find that your home already uses multi-wire branch circuits, such as in the kitchen counter receptacles.

regards, Rod.

I am also a fan of multi-wire branch circuits! Ron, points out the most often seen version, kitchens. Since code requires two different circuits on kitchen counters the logical thing for wire savings is 12/3 for two 20 amp circuits. As pointed out the circuits HAVE to be wired out of phase or your neutral can be overloaded.

[Jim Andrew]

When I remodeled my building to change it into a shop, I ran 12-2, and put the 20 amp 220 outlets all around the shop. Then when I bought my equipment, read all I could on this forum about bandsaws, tablesaws etc, and bought all equipment that needed bigger circuits. So the bandsaw, tablesaw, and sander all have dedicated circuits with 10 gauge wire, and the sander has 8 gauge. So now I'm thinking to just change those 220 outlets out, and rewire the breaker to use 110. Can't ever have too many plug ins.

[Rob Russell]

Rod,

While your electrical posts are generally spot-on, remember that kitchen circuits in the USA must be GFCI (I don't know the Canadian eletrical code). It is acceptable to feed the front end of kitchen circuits from a 2-pole breaker as you describe, but the entire circuit after that needs to be split.

Rob

[James A. Wolfe]

For all of you wiring 2 circuits using a common neutral (i.e. 10-3 110v and 220v circuits) be aware that a tie bar must be installed on the breaker tabs so that if one trips, both open. That way, when you're working on the circuit in the future and turn off the circuit, your neutral will not be current carrying.

[Van Huskey]

Rod,

While your electrical posts are generally spot-on, remember that kitchen circuits in the USA must be GFCI (I don't know the Canadian eletrical code). It is acceptable to feed the front end of kitchen circuits from a 2-pole breaker as you describe, but the entire circuit after that needs to be split.

Rob

That is assuming you use just two GFCI outlets which most people do, if you wire each outlet with a GFCI then there isn't an issue.

[Michael W. Clark]

I used 12/2 for all the 110V and 220V circuits with 20A breakers and 20A corresponding plugs. I have dedicated circuits for the TS (30A 220V, 10/2, with phase converter), air compressor, dust collector, and a separate 220V 20A circuit for future needs. I ran multiple 110V 20A circuits for wall plugs and a sepearte circuit for lights and another one for ceiling plugs.

I know its code for the tape on the white wire, but I didn't use any and the inspector passed it. If you can't tell white is hot on a 220V breaker in the box, you probably shouldn't be messing with it. I should probably mark it in the receptacles, but I used 220V receptacles and labeled the inside of the box and face plate that it is 220 in case we move.

Even if you have duplex 220V 20A receptacles on the same circuit, it doesn't mean you can run two 3HP tools simultaneously. You are still limited by the amperage of the circuit. It may be able to do it if the tools are not pulling FLA, but if they do pull FLA, you could (and should) trip the breaker. The breaker is there to protect the wire and receptacle.

[Dan Hintz]

I know its code for the tape on the white wire, but I didn't use any and the inspector passed it. If you can't tell white is hot on a 220V breaker in the box, you probably shouldn't be messing with it. I should probably mark it in the receptacles, but I used 220V receptacles and labeled the inside of the box and face plate that it is 220 in case we move.

And that's where the problem lies... everyone does this work thinking either they'll be the only ones touching it or anyone else who does touch it will immediately understand what they're looking at. It leaves no room for error, it leaves no room for modifications down the road by someone who isn't fully clued in and a third party takes possession later on.

It's tape... the only reason not to use it and properly mark the line is laziness. The time you spent marking the box could have just as easily been used to tape the wire. I now have to be extra careful because the guy before me thought the same way... can't count the number of lines I thought were dead because I flipped a switch, only to find out he wired the neutral, or he used single breakers on a double line, etc. Do it right once and save everyone the trouble down the road, including yourself.

[Michael W. Clark]

And that's where the problem lies... everyone does this work thinking either they'll be the only ones touching it or anyone else who does touch it will immediately understand what they're looking at. It leaves no room for error, it leaves no room for modifications down the road by someone who isn't fully clued in and a third party takes possession later on.

It's tape... the only reason not to use it and properly mark the line is laziness. The time you spent marking the box could have just as easily been used to tape the wire. I now have to be extra careful because the guy before me thought the same way... can't count the number of lines I thought were dead because I flipped a switch, only to find out he wired the neutral, or he used single breakers on a double line, etc. Do it right once and save everyone the trouble down the road, including yourself.

Dan,
I can add the black tape to the white wire easy enough by pulling the receptacle out and taping the wire. I labeled the inside of the box with a label that says "220V". The cover plate has the same adhesive label that says "220V". The receptacle is a 220V receptacle that physically cannot accept a 110V plug. I may not have done it per code, but I don't think I was lazy and and the labels are more descriptive. The inspector liked it.

As far as the panel. If someone looks at a 2-pole breaker and a white and black wire are connected to it, and they do not know that the white wire is hot, then a strip of black tape will likely not clue them in either. If all the wires were the same color in the panel, a competent person familiar with the equipment would be able to discern what is hot in the panel based on their understanding of the equipment (not saying its the proper way to do it, but it could be done).

I am only saying that if you are willing to touch a wire connected to a breaker thinking that it is not hot because of its color, taping it would probably not have prevented the accident. Safety rules are necessary but they can only go so far. I copied what was already there in the panel that passed inspection in 2007. What keeps someone from touching the main buss, its not black, its pretty and shiny?

Edit: Just noticed you had some instances with a hot white wire. I always check voltage with a voltmeter before I touch any wires or do any electical work. This is a safety requirement by most standards. If you don't follow safety practices, the methods in place will not protect you. That wire is just as hot with or without black, red, purple, or any other color tape..

[Dan Hintz]

If you don't follow safety practices, the methods in place will not protect you.

Oh, the irony in such a statement...

[Van Huskey]

Michael, I don't want to pile on but I just don't understand. You obviously know one is supposed to mark a white wire that is hot and the correct way to do it is with black tape that is almost surely on your belt or in your box next to you as you wire the circuit. What I don't get is you go to the trouble of marking the inside and outside with 220V labels but not bother with the standard marking which my most measures is much easier. To extend your logic anyone that looks at the receptacle housed in a box should immediately be able to tell it is a 240v circuit and know what to expect when they open the box and wouldn't need the 220V labels. I guess my question would be since you know the correct way to mark the white wire as hot and it is easy and cheap why would you buck convention and code?

[Michael W. Clark]

Van,I did the labels for my own benefit. I had multiple outlets in the shop with 12/2 wire. Some were 220V, some were 110V, and some were dedicated circuits. I wanted to distinguish which boxes were which. I had a drawing, but wanted to physically label them. I wasn't intentionally bucking the code, thought I was going above and beyond, and this particular inspector agreed. There was no need to tape the wire as the boxes were labeled. I could have easily taped the wire if the inspector told me to do so.

Dan,we should all take personal responsibility for our safety. For example, if you don't know how to use a TS, take the time to learn about it, or, better yet, get someone to show you how to use it. If you don't know that a 2-pole breaker has two hot wires, then you probably should go learn more about it before messing with it. Codes and wire colors do not take the place of checking voltage, understanding the circuit, and the equipment you are working on. If that white wire with black tape is hot and I touch it, do I not get the same shock from it as I would a black wire with the same volatage? I want to go home to my family everyday in the same condition I arrived at work. I'm not going to depend on that white wire not being hot, just because it is code. I check it.

[Steve Meliza]

The reasons for wrapping black tape on a white wire not being used as a neutral are less obvious when you have a home run of romex because it is easy to see what the wire is attach to at either end and the romex keeps the wires for that circuit nicely grouped together. Imagine instead that you have a junction box with 3 or more runs of romex entering it or have conduit with THHN wires in it, both with a mix of white wires serving as both hot and neutral. When you don't have a breaker or receptacle handy to show you the purpose of each wire then you tend to depend on insulation color. Confusion leads to danger, danger leads to getting zapped, getting zapped leads to the dark side.

I disagree that you went "above and beyond" as that would mean that you met code and then did something that the code doesn't require in order to make the circuit better. Code allows you to use EMT for the circuit ground, but experienced electricians will go "above and beyond" by also running a ground wire inside the EMT to ensure the path to ground is never broken. Your inspector interprets the code and dictates what measures are required to meet code, so legally you can say that the inspector allowed an alternative marking means for this particular installation. That is my personal view so don't let that detract from your sense of satisfaction at doing a job that the inspector found to be safe and conforming to code.

[Michael W. Clark]

Steve,
Thanks, that is more correct that I was allowed an alternative marking means rather than going above and beyond. Point well taken about the juction box. My runs were labeled coming into the subpanel.

If troubleshooting a system or working on wiring that is (or could be) connected to power on the other end, I still think it is a good idea to always check the voltage before working on the circuit. Make sure that it is safe and prevent others from turning it on while you are working on it. I usually check the voltage between each wire and ground. You don't always know that you have turned off the correct breaker or if the circuit is being back-fed from something else. Seems safer to me than just assuming its not hot because of convention.

I knew a maintenance guy that once said "Those wires don't look hot." Then he touched them and got zapped. It was 480V, small horsepower motor (2-3HP). Luckily, he was not hurt, but I'm sure that would not be my luck.

Ya'll convinced me. I'll add black tape to the white wires on the 220V circuits, eventually. Its the proper way. And I don't want to be "lazy". (just kidding Dan, I do respect your comments and read many of your posts on here.)

Back to the OP...12/2 on 20A 220V and 110V outlets. Go up from there depending on equipment requirements or anticipated future needs. I would hesistate to use 14/2 in a workshop unless maybe for a dedicated lighting circuit or other circuit with a light load. IMHO

Mike