Abstract: The windings of the electromotor at the starting are connected to the main power through starting resistors for a very short period of time, before being directly connected to the main power source.A voltage is initially established at the terminals of a voltage control resistor provided by at least one of the starting resistors, or a fraction thereof, before the running of the motor will occur and the direct connection of the motor windings to the main power is allowed only when the voltage across the voltage control resistor has decreased with respect to the voltage initially established at the starting of the motor. The temperature difference between the voltage control resistor, or a fraction thereof, and the ambient is also sensed and any new start of the motor will be prevented till the temperature of the control resistor is not adequately decreased.

Abstract: A refrigerating system in which a refrigeration fluid medium is flowing in a closed circuit comprising a compressor, a condenser, a receiver for containing the refrigeration fluid in a liquid state, and an evaporator serially connected between the outlet side and the intake side of the compressor; the improvement consisting in a cooling device for the compressor, comprising an auxiliary flow path for circulation of the refrigeration fluid, branched-off between the fluid receiver and the intake-side of the compressor and provided with a flow restrictor. Pressure sensing elements are provided on the intake side to provide a control signal in the absence of liquefied fluid in the receiver.