... protections ,Automatic Voltage Regulation (AVR) Function ,multi-step speed , multiple torque setting source ,output freq.0.1- ... be realized. B504 Economic sensorless vector control inverter :Power Range:Single phase 220V 0.5HP-3HP (0. ... 150%-1 minute 180%-10 secondsTransmitter signal0~10mA,4~20mA,0~20mANo.of V/F PatternsVector curve, ... New Sensorless Vector Control Inverter,B504 Variable Speed Drive !