Dry-Run Protection for Deep Well Pumps

A deep well pump must never run without water. The water lubricates the bearings and cools the motor, and a pump that runs dry can be damaged in a short time. Wells make this a real risk: in a dry season, or when the pump draws more than the well can give, the level can fall to the inlet.

Ways to protect the pump

1. Set the pump correctly: inlet at least 1 m below the dynamic water level, measured at the real duty flow.
2. Fit level electrodes in the well, one above the pump inlet to stop the pump and one higher to allow a restart.
3. Use a control panel that also watches the motor current. A pump that loses its water draws less current, and the panel can stop it.
4. Add a restart delay, so the well has time to recover before the pump starts again.

Check the well, not only the pump

If the protection trips often, the well is being pumped harder than it can give. Choose a smaller flow size, or run the pump for shorter periods with time to recover between them.