Replies

1. 
   Jeff_Patrick | Mar 14, 2002 04:46am | #1

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   Single pole are for 110volt and double are for 220volt. I strongly suggest that you learn much more than you apparently now know before proceeding. There are many good books (support your local library) on the subject that will teach you the basics and everything else. You should probably hire a professional.

1. 
   Donald_C._Brown | Mar 14, 2002 05:22am | #2

   *thomas-Improper electrical wiring kills many people in this country every year. Hire someone who knows what he's doing (an electrician). Don't rely on the Internet to answer your electrical questions. It's serious stuff.

1. 
   RonTeti | Mar 14, 2002 05:50am | #3

   *thomas not to be insulting so please dont mis understand, like Donald said basically if you have to ask that kind of question for your own safety hire someone to do it.

1. 
   thomas_witt | Mar 14, 2002 02:58pm | #4

   *Thanks for the info and the concern guys!I have done quite a bit of wiring and it has all been sucessful. Just could'nt find an explanation of those terms in my books on the subject.I did suspect that was the answer though. So in a sense, to ask for a 220 volt double pole circuit breaker is redundant? Tom

1. 
   Bill_Donovan | Mar 14, 2002 09:13pm | #5

   *Tom,In regards to the earlier posts, yes PLEASE be sure you know what you're doing. You'll be working at the main breaker and in my house that's 200 amps. If you accidentally touch those bus bars and they're live... hope you have good life insurance. I'm not an electrician but I read a lot (books and the NEC code) plus I have friends that are electricians. It's amazing what good beer and good food will get you! Pay particular attention to wire gauge in relation to amps. Other electrical mistakes will just not work but THIS one will start fires.The reason for double poles is to avoid a brownout situation to the motor etc. When you rewire a motor for 220, each field on the motor is supplied by one leg of the 220 volt circuit (110 volts each). If the circuit breaker wasn't tied together physically(although some makes only have a single bar on the outside) and you tripped one side only, the motor would get half the voltage you rewired it for and cause it to overheat etc.Again, can't stress enough the need for safety and knowledge when dealing with electricity. Some electricians will review your work for a reduced fee if you feel pretty confident doing the actual wiring. If this is the case, wait to energize the new circuits until they give the OK. P.S. Most DYI books are pretty sketchy on the 220 stuff because many people would have problems working with it. The B&D book is pretty good but look to the library as the other post said for a better selection. Good luck.

2. 
   Steve_Schefer | Mar 14, 2002 09:46pm | #6

   *Thomas, the answer to your question is that there are single throw double pole breakers for 220 and there double throw double pole breakers for 110. For the reasons mentioned about brown outs, only use a single throw double pole breaker on 220. The double pole double throw breakers must never be used for 220 but they do provide a convienent way to add two 110 circuit breakers in single package.Above all, follow the advice before this and consult your local building codes before installing any electrical circuits.Steve

3. 
   BarryO_ | Mar 14, 2002 09:54pm | #7

   *> The reason for double poles is to avoid a brownout situation to the motor etc. When you rewire a motor for 220, each field on the motor is supplied by one leg of the 220 volt circuit (110 volts each). If the circuit breaker wasn't tied together physically(although some makes only have a single bar on the outside) and you tripped one side only, the motor would get half the voltage you rewired it for and cause it to overheat etc. This isn't true for any 101/220 motor I'm familar with. When wired for 220, the 2 sets of coils are wired in series, which is placed across the two hot lines. No connection to the neutral is made, so if just one of the breakers were to open, power would not be supplied to the motor -- no fear of overheating.It would be a safety hazard, however. It would appear that the motor was unpowered, when in fact the windings would be supplied with 110V from the other breaker -- dangerous.In other types of 220V circuits, there would be a concern that current unbalance with just one breaker open would cause higher current flow in a neutral, above its design load.

4. 
   thomas_witt | Mar 15, 2002 02:33am | #8

   *Thanks for the discussion and explanation of the "double pole" question. I've never seen it explained before in my books. If anyone wants to put in some recommendations on electric wiring books I think it would be helpful. Again, thanks for the concern and I hope everyone reading in hears it. One can get badly hurt or die doing this if one is not careful. However, this is far from my first time with 220. This will be the third shop I've wired. The one thing I absolutely will not touch is Three Phase. We have a lot of that in this building and if I ever get a three phase machine I'm calling the electrician! Regards, Tom

5. 
   Bill_Duckworth | Mar 15, 2002 04:20pm | #9

   *In response to your request, "If anyone wants to put in some recommendations on electric wiring books I think it would be helpful," Rex Cauldwell's "Wiring a House" is one of the best books Taunton Press has ever published.

6. 
   Bill_Donovan | Mar 15, 2002 08:33pm | #10

   *Tom,There was a post on wiring a shop on the finehomebuilding discussion page as well. I had previously incorporated some of the items in my basement shop. For what it's worth:- Added a separate sub-panel for the shop with a 220 disconnect (lockable). All shop power comes off this panel. I have young kids and this is to prevent their curiosity from causing a terrible accident.- A small red light located by the shop exit alerts me to the fact that the shop power is on (wired directly off the panel). The kids have been warned about the danger but the only real protection is prevention.- The shop lights are off the main panel so that in case I manage to trip the sub-panel, I won't have to group around in darkness.- This approach probably added only $150 to the entire job but allows me to sleep a lot easier!

7. 
   Seth_Frankel_ | Mar 16, 2002 12:41am | #11

   *I'll second the recommendation for Rex Cauldwell's i Wiring a House. It puts to shame all the Black and Decker and Home Depot variety wiring books.Best,Seth