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Old 03-11-12, 01:08 PM   #18
nexsuperne
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(voltage goes down- current goes up)


How?basic ohms law- if the potential difference goes down (incoming voltage decreases) then across a fixed resistive load the current and power across the load will decrease. Eg if you have 100volts across a 1 ohm load, then it will pull 100 amps. If you decreased the voltage to 50v, then across the same 1 ohm load, it will pull 50 amps. I=V/R .

The power quadruples when the voltage is doubled or the resistance halved. P=VI eg the same 100 volts at 100 amps will be 10000 watts. At 50 volts, and 50 amps, the power is 2500 watts.

If you lost a phase on a 3 phase supply, then the remaining 2 phases would overload at certain points in the 3 phase motors rotation. This would cause a breaker to trip.

I guess you are talking exclusively about inverter drive technology, not the old school stuff!
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