float switches are the cheapest option, but they can and do go wrong. the key is reducing the number of cycles.
for example, if the pump is in a small tank/area to be emptied, then the pump will empty the tank, and then cut out. the water will then fill the tank, and pump will kick in again, so to reduce the number of times it has to do this, there are a few options.
1)increase the size of the area to be emptied
2)choose a pump that will empty the area slowly, but no too slowly, that the area will overflow.
3) govern the pump back so that it empties the area slowly (if you get the pump to pump water, anbd then close the valve slowly, eventually you will hear a change of pitch from the motor. Once past this point, you are liable to damage the pump, and it will cavitate)
4)use a liquid level relay and level probes, which can have a time delay built in.
also, ensure that your sump pump has a non return valve directly after the pump, and a normal valve (ball valve) directly after that. this ensures that when the pump stops, the water doesnt syphon back, and the ball valve is so that you can maintain the NRV without getting wet.
This is assuming you re using solid pipe, and not layflat hoses.
john
