DNK
"JDB is correct with the 13.4 amps though...assuming this is a multiwire with nuetral pulled...I don't see how you would get 1700w a on one phase and 1500w on another with a straight 208V load...."
HE is correct with 13.4 amps. His results and mine are the same. The load shown is 2 single phase loads connected phase to neutral with a net neutral current of 13.4 amps.
"If you only ever measured between the A leg and the B leg, say because you had a single phase load connected A to B, then you would only have a single sine wave to look at, and thus _no_ phase angle difference to consider."
Winnie
The single sine wave you refer to is the net result of the addition of phase A and Phase B. There are times when phase A is at
about 170 volts and Phase B is at another value that results in a single sine wave. The phase difference still exists.
"If you have two legs of a three phase wye system, then _referenced to neutral_ the two legs will be 120 degrees apart. But if you only connect a single phase load between A and B, at any instant in time the current flowing from phase A will have to exactly match the current flowing to phase B."
The current wave form follows the voltage wave form if the load is resistive. If its inductive then the current does not follow the voltage. The currents add as vectors just as the voltage and as you say at any point on the sine waves the resultant currnet in both phases are the same.
" Referenced to neutral the _voltages_ may be 120 degrees apart, but referenced to each other the current flow is exactly the same (meaning a 0 or 180 degree phase difference depending upon your sign conventions)."
That is not correct. Again the currents are added as vectors as said above. If you look at my first post I added the current as vectors.
[This message has been edited by Bob (edited 03-10-2006).]
