2007-09-09 06:47:21 · 3 answers · asked by dgoosed1 1 in Science & Mathematics ➔ Engineering
Household 240v in the US is usually single phase. It is delivered as a 3-wire dual voltage. Each 'hot' leg is 120v phase to neutral. Because the two 'hots' are 180 degrees out of phase the voltage is 240 'hot-to-hot'.
Keep in mind that some US households actually use 208v which is the phase to phase voltage in 3-phase system when the phase-to-neutral is 120v. (That is each leg to neutral will be 120v but because they 120 degrees out of phase will measure 208 phase to phase.)
And please never refer to the neutral as the ground. Although the should both be at ground potential they serve entirely different purposes and should never be interconnected except at the distrubution load center (i.e. main breaker box)
2007-09-09 07:19:49 · answer #1 · answered by Jim E 4 · 3⤊ 0⤋
Single phase. A 440 volt 3-phase supply measures 240 volts rms phase-to-earth. You will generally finf in a street that some of the houses are on phase A, some on phase B and some on phase C. If one phase fails, not all the street goes off.
2007-09-09 13:55:24 · answer #2 · answered by Michael B 6 · 1⤊ 2⤋
As an electrician in Canada Jim E is right the other guy is way off
2007-09-09 15:04:41 · answer #3 · answered by Sparky the wonder 2 · 2⤊ 0⤋