Type 1215----1228 are of medium and small capacity water-filled, sealed constructions, water-submersible, three phase asynchrocous motors.

Typically the motor is comprised of stator, rotor, thrust bearing, guide hearings, compensation bag and scals, stator windings are wound with wspecially insultated water-resistant winding wire which ensures extremely high dielectric strength and heat resistance. Rotor is of squirrel-cage type, Thrust bearing and guide bearings are made of extre-strong and wear-resistant material, suitable for water lubrication. The thrust bearing is fo special construction, thus the capability of taking pump axial thrust is greatly strengthened, An excellent sealing device is installed at the shaft extention side to prevent the entrance of well water into the motor, An elastic rebber bag is installed at the bettom to equalize the motor's internal water contraction/expansion pressure with the well water submergence pressure.

Tyep 1234 motors ate of larger capacity submersible motors, In order to increase the ability of heat-dissipation. Pipe lines are welded on the motor housing. The motor's internal cooling water cireulates through the pipe lines, and the well water outside of the housing carries away the heat.