Quote:
Originally Posted by kf4rca
Did you know that in New York City the electric utility supplied DC power to the old warehouse district until 2007 so those businesses could operate their old DC elevators?
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On the AC side, old elevators and "lifts" in Philadelphia and other cities that once used two phase (240 volts, 4 wires, 90 degrees out of phase). Later on, those same buildings were fitted with 3 phase to two-phase transformers, so the "old elevators" could still be used when overheads were upgraded to 3 phase, 120 degrees phase lag. It was not as simple as replacing a motor.
