1.automatic pump alternation,select single pump control when needed for motor maintenance. 2.led linghts indicates water level, motor status 3.motor over-run protection 4.Automatically transfers to non-operating pump when current pump is overloaded. 5.Three second time delay for liquid level detectionto prevent inaccuracy caused by ripples. 6.Alert signal will be sent when incorrect electrode rod is intalled or wiring get disconnected. 7.Two sets of terminals available for monitoring liquid level,abnormal signal and operating status. 8.Remote monitoring with RS485/MODBUS/RTU.