Automatic change over switch-L200(50amps).It's monitor the water tank.and when its upto 30%lower..its will pump water automatically...and if it 98%full..its will switch off the PUMPING machine automatically. It's also change over from PHCN to GENERATOR and switches off GENERATOR automatically..It's also set timer for the duration of your GENERATOR..It's also serves as STABILIZER..if the current of PHCN is high/low its will switch off every appliances in the house.Its also has a graphical interface. etc..