You are perfectly right: the same here in Belgium: neutral is the middle of the 380 3ph, it should never be grounded; 1 ph + neutral gives 240V (used to be 220V >30 years ago). To get 3ph 380 at home one needs to convince the power distributor otherwise one gets 1 ph + neutral only.
2009/5/4 Bruce Hayden <[email protected]>: > 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 <[email protected]> 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:[email protected]] On >> Behalf Of John Harris >> Sent: 04 May 2009 17:05 >> To: [email protected] >> 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 <[email protected]> >> To: [email protected] >> 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 <[email protected]> >>> 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 > -- Kris Buelens, IBM Belgium, VM customer support
