DEVICE TO PROTECT SUBMERSIBLE PUMP MOTOR AGAINST OVERLOAD AND DRY RUNNING Russian patent published in 2012 - IPC H02H7/08 

FIELD: electricity.

SUBSTANCE: device comprising three transformer reactors installed into phases of a supply circuit, a three-phase half-wave rectifier, also a potentiometer and a capacitor connected to outputs of the three-phase half-wave rectifier, a voltage divider made on three resistors, one of divider's outputs is connected to a bus +Usupply, and the other one - with a common bus, two comparators, an inverter, the first and second light diodes, a logical element 2OR, a time delay element, an output relay, a contact of which is connected into a control circuit of an actuator, the input is connected to the output of the time delay element, and the output is connected to the bus +Usupply, power contacts of the output relay are connected into phases of the supply circuit, additionally the following components are introduced - the voltage divider resistor, an off button that shunts this resistor, and an on button connected in parallel to the voltage divider resistor connected to the inverting input of the first comparator.

EFFECT: improved reliability of the proposed device operation.

1 dwg