DEVICE FOR PROTECTING ELECTRIC MOTOR OF SUBMERSIBLE ELECTRIC PUMP AGAINST OVERLOAD AND "DRY STROKE" Russian patent published in 2010 - IPC H02H7/08 

FIELD: electricity.

SUBSTANCE: device includes three transformers installed into supply main phases, three-phase rectifier, potentiometre, two comparing units, two light emitting diodes, electric motor current indicators, logic element 2OR, output relay the contact of which is connected to control circuit of actuating device, and power contacts of output relay are connected to supply main phases, time delay unit; to the device there introduced is smoothing capacity connected to outputs of three-phase half-wave rectifier, voltage divider made on three resistors, one of its outputs is connected to bus +U_power, and the other - to common bus; voltage divider is also connected to inverting inputs of comparing units; inverter the input of which is connected to output of the second comparing unit, and output is connected through resistor to the input of the second light emitting diode and to the second input of logic element 2OR. Time delay element the input of which is connected to output of logic element 2OR.

EFFECT: improving operating reliability of device for protection of electric motor of submersible electric pump against overload and dry stroke.

1 dwg