UO3 series 3-inch submersible motors – Ideal for water-wells of 3-inches or larger diameter Easy to repair or rewind as fitted with CSCR and CSR system, 3 Inch Oil Lubricated Motors are fitted with enameled copper wire (Class-H) for stator winding. For flawless sealing this submersible motor is fitted with a mechanical shaft seal of carbon and ceramic and an oil seal of Nitrile rubber. But that’s not all, pressure equalizing rubber diaphragm protects from the pressure and volume variation. Hence, 3 inch Oil Lubricated Motors are used for fountains, gardening/horticulture, pressure boosting units.