DEVICE FOR PROTECTING ELECTRIC MOTOR OF SUBMERSIBLE PUMP AGAINST OVERLOADING Russian patent published in 2007 - IPC F04D15/00 H02H7/08 

FIELD: electric engineering.

SUBSTANCE: device comprises three current transformers connected to the power supply, three-phase full-wave rectifier, potentiometer, RC-circuit with diode, first comparator, indication element, output relay, two comparators, and current transformer connected to one of the power source phases. The first output of the transformer is connected with the common bus, and the second output is connected with the inverting input of the second comparator. The inverting input of the third comparator is connected with the phase wire of the same phase. The output of the second comparator is connected with the first input of the 2AND and 2AND-NOT circuits. The output of the 2AND-NOT circuit is connected with the second input of the 2AND circuit whose output is connected with the inverting input of the integrator whose output is connected with the first output of the switch. The second output of the switch is connected with the resistor that is connected with the capacitor and non-inverting input of the repeater whose inverting input and output are connected to the common point that is connected with the second input of the OR circuit and second RS flip-flop whose output is connected with the second indication element.

EFFECT: enhanced reliability.

2 dwg