The construction, seals and protective monitoring contribute to the motor’s ability to operate in and under water.
by George Weihrauch, Baldor Electric Company
  • Carbon ceramic-faced seals are general purpose, stainless steel seals that are typically used in food processing, petrochemical and wastewater applications with relatively clean effluent.
  • Tungsten carbide-faced seals are popular types that provide harder seal faces for more demanding applications in more viscous fluids.
  • Silicon carbide-faced seals are typically used for the most demanding slurry type (highly viscous fluid) applications.


No matter the material of construction, seals are wear devices. Surface abrasion on the outer seal could lead to seal failure, allowing fluid to enter the motor. In this situation, the oil chamber and moisture probes provide a key safety feature for long motor life. The probes are set to the resistivity of the oil that fills the chamber. If the outer seal fails and water mixes with the oil, the moisture probes detect the moisture influx and send a signal, via a control module, to a control panel warning alarm. This gives the user time to shut down the pump, change the outer seal and restart the motor.

Submersible motors are not like other induction motors. They are specifically designed to safely operate in and under water. Their rugged construction, secure sealing and protective safety monitoring provide long life and safe operation with pump equipment.