The US 220 came from the days of single phase split winding transformers yielding 110 to Neutral. Not a three phase thing but, the "open-delta" two phase transformers used in residential distribution, were two split winding transformers wound is a three phase style with the third winding missing. It also provided splits for 110V and are truly a two phase system. But a matter of semantics. The open delta transformer was a cost reduced virtual three phase????!!!.
--- mkel...@es.com wrote: > > Just out of curiosity, where does the designation "220V come from? If you > measure the potential difference between two phases of a three-phase system, > you get 208V. If you measure the difference between the two phases in a > residential or light commercial area, you would probably get 240V. > > So, where does the term "220V" come from? > > Thanks, > > Max Kelson > Evans & Sutherland ===== Best Regards Hans Mellberg Regulatory Compliance Consultant and Design Services By the Pacific Coast next to Silicon Valley Santa Cruz, CA, USA 408-507-9694 __________________________________________________ Do You Yahoo!? Yahoo! Auctions - buy the things you want at great prices http://auctions.yahoo.com/ ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
