Lots of discussion on this.. I'm no expert, but it didn't sound right. I found 2 relevant articles on Wikipedia: http://en.wikipedia.org/wiki/Three-phase_electric_power http://en.wikipedia.org/wiki/Split_phase
So, your dryer, oven, etc. in a U.S. home runs on split phase power, *not* 3 phase. (2 phase power is not the same as split phase.) And your reference to "ground" should be "neutral". The ground wire should never carry a current - if it does, then you have a problem. It is there for safety. The neutral wire (I've heard it called the "grounded conductor") can carry current for loads that require a single phase. I agree with what you said about 3 phase in commercial installations. Note: My experience is only the U.S.A. - what you say may be true for the U.K. On Mon, May 4, 2009 at 12:52 PM, Dave Wade <g4...@dpwade.eclipse.co.uk> wrote: > 2 Live + ground is two phase. A three phase supplies doesn’t need a ground, > but usually one is provided to allow single phase equipment to be used. > > > > Power is generated by three phase alternators and these expect the load on > each phase to be identical. > > > > So in most areas of buildings where high power is used (e.g. a large machine > room or server centre) there will be outlets connected to each of the three > phases and attempts made to balance the load across the phases. > > > > Certainly in the UK using the power in an unbalanced way may result in > financial penalties. > > > > Typically three phase equipment performs the balancing internally so are > “desirable” from the suppliers point of view. > > > > Even when we ran 4381’s we still had a mix of three phase and single phase, > but of course we are on 22volts. I don’t think there is any three phase > stuff left in our machine room any more. > > > > Dave Wade G4UGM > > Illegitimi Non Carborundum > > > > -----Original Message----- > From: The IBM z/VM Operating System [mailto:ib...@listserv.uark.edu] On > Behalf Of John Harris > Sent: 04 May 2009 17:05 > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: z890 power: 3 phase vs 1 phase? > > > > The main difference between single phase and 3-phase (basically a ground and > 2 live circuits) is the resultant voltage. > > Single-phase = 110v US and 220v UK > > 3-Phase = 220v US and 385v UK > > All heavy duty applicances in the US (A/Cs, Washer/Dryers, Electrical > cooktops etc) use 220v,(3phase). > > By supporting 3-phase, appliances can run in a multi-tude countries and the > manufacturer only has to worry about the frequency i.e. 50/60hz between the > regions. > > I had one pulled into my garage for my 220v tools. > > My 2-cents worth > > John Harris > > IBM > > ------ Original Message ------ > Received: 11:37 AM EDT, 05/04/2009 > From: Dave Jones <d...@vsoft-software.com> > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: z890 power: 3 phase vs 1 phase? > > That's right...the z boxes basically have an a/c system built into them. > The a/c units here at the house (living here in Houston, we know a > thing or two about a/c....) both run on three phase power. > > Alan Altmark wrote: >> On Monday, 05/04/2009 at 08:57 EDT, Dave Jones <d...@vsoft-software.com> >> wrote: >>> Well, the z boxes all have motors to drive the fans, but I do not >>> understand why they would need 3 phase power..... >> >> Don't forget the coolant compressors. >> >> Alan Altmark >> z/VM Development >> IBM Endicott > > -- > Dave Jones > V/Soft > www.vsoft-software.com > Houston, TX > 281.578.7544 > > -- Bruce Hayden Linux on System z Advanced Technical Support IBM, Endicott, NY
