Abstract: A motor drive, particularly for submersed electric pumps, has a jacket closed hermetically by a bottom and a head in order to form a first hermetic chamber, which contains an electric motor that is immersed in a bath of dielectric cooling liquid; the jacket is associated with an enclosure in order to form a second hermetic chamber, which contains a power supply and control unit connected to the electric motor. The motor drive includes a compensation means that balances the variations in volume of the dielectric cooling liquid and generates an overpressure within the first hermetic chamber, the first hermetic chamber is substantially independent of the second hermetic chamber.

Abstract: A method and device for starting single-phase asynchronous motors which substantially consists in disengaging the start winding of a single-phase asynchronous motor, after its starting, by using a switching means that is connected in series to the start winding. The switching means is controlled as a function of a starting time and of a starting voltage.

Abstract: A power supply and control unit for submersed electric motors includes an enclosure which is jointly connected to the motor of a submersed electric pump and forms a hermetic chamber that contains an electronic power supply that can be connected to the motor. The unit includes a heat exchange means in the liquid state that completely fills the empty space within the hermetic chamber yin order to transfer to the enclosure the heat generated by the electronic power supply.