This model is suitable where overhead tank capacity is small and underground tank capacity is large. 

This controller is suitable for controlling the  overhead tank water supply as soon as the overhead tank gets empty. The pump will start and the underground tank water will be transferred to overhead tank. The pump will be stop when the overhead tank gets full.

The controller has a protection for pump Dry run safety which senses the water reaching to overhead tank within the 60 seconds whenever pump starts. If the water is not reaching to the overhead tank within the specified time, it trips the pump and gives audio visual alarm. Thus, protecting the pump from damage. The audio-visual alarm will be reset by the application of Reset switch & pump will start if dry run fault is rectified.

Note: if water is supply from underground tank & incoming water flow will be very high ball valve required to stop underground tank overflow.