220V Electrical

[Gary Petit]

I am going to start running electrical for my woodshop. I have a few questions and am by far no electrician. The questions I have are changing my 110 to 220v. My 15inch planer is already wired for 220 20 amp. I plan on changing my table saw to 220 and my radial arm saw. The question I have is can I put that all on one 20 amp circuit? The tools will not be ran together only separate. Or is that to many wires going into one circuit? I have a 60 amp sub panel. I need to leave room for my dust collector 110 v for its own circuit, and the same for my air filtration system on its own circuit also, which is 110v. Then I need a couple more 110v outlets for my jointer, bandsaw, and router table.

Main question is it possible to do that with 220v circuits if I am not running them together.

Thanks,

Gary

[Von Bickley]

Yes..... That should work O.K.

[Ian Scofield]

Should work fine, however make sure you do some load balancing. 220v is just spread across two 110 legs that are 180 degrees off of eachother. Therefore, your main tools will be providing an equal load to each of these legs. When you add your 110 elements, ensure you're spreading them evenly across those two legs. IE dust collector on leg 1, air filtration on leg 2, etc.

I'm sure some EE major will come along and correct me somewhere in this, not claiming to be an expert*

[Art Mann]

Paying attention to balancing the 120V loads is an important point if your feed circuits are marginal in size.

Perhaps you already know but I will mention it just in case. The nominal voltage is now 120V line to neutral and 240V line to line. If you measure 110 or 220 volts with a voltmeter, you need to call an electrician or perhaps your utility company. When I started reading 110V and less in my shop, I investigated and discovered that the neutral wire was not connected at the utility pole. I called the power company and they came out and replaced the bare aluminum neutral wire going to my house because a squirrel had gnawed the wire in two. I promise I am not making this up. The lineman told me it happens all the time.

[Charles Lent]

A broken Neutral will give you fits. I'll bet that you aren't seeing the lights flicker much any more and you aren't replacing light bulbs much any more either.

I got a free meal at a fine restaurant one time. Their lights were flickering big time and I commented to the waiter that I knew what the problem was. He ran off and I was soon visited by the chef/owner and the rest of the kitchen help. They told me that they had 3 electricians look at it and none could figure out what was wrong.

I went from my dinner out to the kitchen, opened their main electric panel, wiggled the main Neutral wire terminals, and one of them sparked significantly. With an insulated screwdriver from my car I tightened the terminal and the flickering problem was gone. I told the owner that he needed to have an electrician repair it properly, since the Neutral wire end and terminal were in very bad shape. I then put the panel back together and went back to my meal, but they had replaced it with a new hot meal (Filet Minion this time) and included a bottle of wine and cheesecake desert. I ate well that night.

Charley

[Gary Petit]

I am trying to understand the balancing of the legs. Is a leg on the left and right side of the electrical bar running down the box? So if my 220 circuit is on the top left, you are saying to balance my dust collector on the right side of the 20 amp circuit? and my air filter put back on the left side with the 220v circuit? Am I understanding this correctly? Thanks

[Jason Roehl]

I am trying to understand the balancing of the legs. Is a leg on the left and right side of the electrical bar running down the box? So if my 220 circuit is on the top left, you are saying to balance my dust collector on the right side of the 20 amp circuit? and my air filter put back on the left side with the 220v circuit? Am I understanding this correctly? Thanks

No. The legs alternate down each side--that's how you get 240V, and why a double breaker is used. Each leg supplies 120V towards that 240V, and each section of the double breaker has one leg feeding it. If you were to see a panel with no breakers in it, it would be obvious.

This link shows a panel with no breakers: http://i.stack.imgur.com/hk18c.png

Note that the breakers attach to the center posts of the bus bars, which alternate from each leg (labeled 'A' and 'B' in the link).

"Balancing" a breaker panel means attempting to put roughly 1/2 the normal electrical load on each leg, which would, of course, only apply to 120V circuits.