We had to rewire our dryer from a 4 prong to 3 prong outlet for our house (built before the 4-prong code). It is hot/hot/neutral (black/red/white if I remember correctly), with the case wired to the neutral. I believe 110 is used to run the small stuff (light and buzzer), and 220 runs the heavy stuff. If you go to the local hardware store they sell both 3 and 4 wire cords and you can look at the color scheme. Mark On 12/11/2009 5:27 PM, Sean Breheny wrote: > Hi Mark, > > I just looked up what you said and it seems that the distinction is > not between houses and mobile homes, but between new and old > construction: > > http://fixitnow.com/appliantology/dryercords.htm > > This says that the latest codes require a 4-prong plug > (hot,hot,neutral,gnd) for 220V appliances in the US. Older homes > usually have only 3-prong plugs (hot,hot,neutral) for 220V circuits, > and as you say, in these cases, the neutral is connected to the case > of the appliance. > > Interesting, because I don't think that connecting the neutral to > something "human touchable" is very safe since there could be a single > point of failure which would electrify the case (an open neutral in > the connection back to the breaker box). I always thought that > three-prong 220V outlets were hot,hot,gnd not hot,hot,neutral. If you > have no 110V stuff in the appliance, neutral isn't needed. > > Sean > > > On Fri, Dec 11, 2009 at 8:05 PM, Mark wrote: > >> My brother does appliance installation. In the USA there is two >> standards for wiring appliances. One is when they are installed in a >> frame built home and another when they are installed in places like >> mobile homes. In frame built homes the plugs are 3 pronged. The outer >> two connections are HOT (red, black) at 120V each or 240V between the >> two and the middle is neutral (white). Ground (green) of the appliance >> is tied to this same neutral. In a mobile home a 4 pronged plug is >> required, where the outer two connections are still HOT (red , black) at >> 120V but the neutral (white) is not connected to the frame and the 4th >> prong (green) supplies an extra ground which connects to the metal frame. >> >> If you look on something like a electric dryer where the connections are >> you will find a metal tab that can be connected to the center neutral to >> bond the frame to the neutral wire if installed in a home. When >> installed in a mobile home that tab is removed and the green wire is >> attached to the frame. >> >> Good Luck >> Mark >> >> >> >> >> >> PICdude wrote: >> >>> FWIW, I opened the outlet, and the three wires are green (tied to the >>> back of the case), then red and black. >>> >>> So I'm confused as to what to do now. I don't mind getting an outlet >>> wired in here, but need to test this thing in the next few days before >>> my DOA warranty runs out. >>> >>> Not sure where else I can find 220V to test this. >>> >>> Cheers, >>> -Neil. >>> >>> >>> >>> >>> >>> >>> >> -- >> http://www.piclist.com PIC/SX FAQ& list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> >> > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist