Run dry protection?

[Alternety]

I have a centrifugal pump pressurizing the house from a storage tank. Is there a way to stop the pump if the tank runs dry? Without putting a float in the tank. I am automating watering so it could possibly empty the tank if a valve stuck or a hose burst.

My thoughts were a pressure drop in the pump input or a recognizable current change in the pump.

The pressure approach, I am not sure there is enough of a recognizable change to stop the pump before damage. I have no idea just how sensitive they are to running dry. A simple pressure switch like I use for turning the pump on and off, before the pump would be fairly easy. But I have no idea if it would provide the necessary protection.

Current in the pump would need to consider changes due to output loading as pressure tanks fill.

Any suggestions appreciated.

 

[Valveman]

A Cycle Sensor is what you need. It actually looks at amps times the power factor, which is more sensitive than just amps.

 

[Sponsor]

 

[Ballvalve]

I have a centrifugal pump pressurizing the house from a storage tank. Is there a way to stop the pump if the tank runs dry? Without putting a float in the tank. I am automating watering so it could possibly empty the tank if a valve stuck or a hose burst.

My thoughts were a pressure drop in the pump input or a recognizable current change in the pump.

The pressure approach, I am not sure there is enough of a recognizable change to stop the pump before damage. I have no idea just how sensitive they are to running dry. A simple pressure switch like I use for turning the pump on and off, before the pump would be fairly easy. But I have no idea if it would provide the necessary protection.

Current in the pump would need to consider changes due to output loading as pressure tanks fill.

Any suggestions appreciated.

For 30 bucks [-] your problem was solved many decades ago with your basic pressure switch with a low pressure cut out. Search anywhere and find them. Square D. Saved my pressurizer pump 50x. Now for a deep well pump you can do the same, but far better with the cycle sensor or franklins pumpsavers. They test the amp draw and reset automatically.