ok folks. This topic needs to be clarified. With respect to each other, by definition, two conductors have a potential difference at 180 degrees. Period. The 90 degree stuff may pertain to current but not to voltage. You would need a four-phase transformer to get 90 degree phasing and simply it does not exist. Voltage, is usually measured: wrt ground, wrt other reference conductor such as neutral or wrt to another voltage (hot) conductor. In some cases, the voltage difference between ground and two other conductors may be 120/240 degrees such as in a three phase system. So, no matter how you measure voltage it will either be at 120, 180 or 240 degrees wrt to some other conductor.
In the US there have been many systems of low voltage (staying below 480V)distribution yielding the following voltages: 480/240/120 480/208/120 from three three phase 480/230/115 single split phase 230/115 single split phase motor control voltage 220/110 single split phase older home voltages 208/120 from three phase 480/277 (for fluorescent lighting) 117 (where did this come from? seen in many older HP instruments) Open Delta (3, 4 or 5 wire, when one is grounded into neutral its called a "stinger") Split phase (three or four wire) Y (four and five wire) Hope this stirrs the pot!!!! ===== Best Regards Hans Mellberg Regulatory Compliance & EMC Design Services Consultant By the Pacific Coast next to Silicon Valley, Santa Cruz, CA, USA 408-507-9694 __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at 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: No longer online until our new server is brought online and the old messages are imported into the new server.
