On 02/27/2012 04:49 PM, Skylar Thompson wrote: > On 02/27/2012 04:40 PM, Edward Ned Harvey wrote: >>> From: tech-boun...@lists.lopsa.org [mailto:tech-boun...@lists.lopsa.org] >>> On Behalf Of Luke S. Crawford >>> >>> On Mon, Feb 27, 2012 at 04:02:44PM -0800, da...@lang.hm wrote: >>>> the math in sine-wave AC circuits is odd, but a 208v circuit is exactly >> 2 >>>> 120v circuits >> >> Actually... I'm quite sure 120V is a single phase (relative to ground), and >> 240V are just two 120V circuits that are directly out of phase with each >> other (2-phase) and 208V is three 120V signals that are each 120deg out of >> phase with each other. >> >> 120V = 1 phase >> 240V = 2 phase >> 208V = 3 phase > > It all depends on how you measure the voltage. 240V split-phase is 120V > phase-to-ground and 240V phase-to-phase. 208V can come as single-phase, > and is 208V phase-to-phase and 120V phase-to-ground.
I just realized that this was kind of unclear - the difference between 120V single-phase and 208V single-phase is that 120V single-phase has a single hot conductor, while 208V single-phase has two hot conductors, -120V and +120V relative to ground. It's still three-conductor single-phase, but 208V and 240V electronics are designed to draw from both hot conductors. -- -- -- Skylar Thompson (skylar.thomp...@gmail.com) -- http://www.cs.earlham.edu/~skylar/ _______________________________________________ Tech mailing list Tech@lists.lopsa.org https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
