Seal failure is a condition where a submersible pump and its motor housing have been compromised. Water has penetrated into the housing which is normally filled with oil. Most pumps have what is known as a double seal: If the first seal fails, it gives us time to do maintenance before (inevitably) the second seal fails.
Seal failure can be caused by many factors including vibration, the pump running dry, improper start up procedures and just plain wear and tear. The old mechanics tell us that there are two types of seal failures: Ones that have happened, and ones that will happen. That's why a seal failure alarm is a good idea when planning your pump controller.
Once water penetrates the housing, major damage is likely. Seal failure is not entirely preventable. It's just a matter of time, usually, before the elements prevail. But detecting seal failure is possible by using a implementing a seal fail alarm into your pump controller box. The seal failure alarm uses probe sensors to detect early failure to the seal and tells the operator the pump needs to be serviced soon.
If you are using submersible pumps, it's a good idea to include a seal failure alarm into the design of the pump controller boxes. For a minimal cost, you can save yourself of your customer lots of potential damage by catching seal failure before it damages the pump and motor. -- Rich Kreekon