AUTOMATIC CONTROL DEVICE OF SUBMERSIBLE ELECTRIC PUMP Russian patent published in 2011 - IPC F04D15/02 

FIELD: engines and pumps.

SUBSTANCE: device includes upper and lower level sensors, direct current relay the normally closed contacts of which are connected to coil control circuit of magnetic starter which connects the electric pump to electric network, step-down transformer the first winding of which is connected through fuse to electric network, and the second winding of transformer is connected to input of rectifier bridge through the circuit made in the form of parallel connected branches one of which represents normally open contacts of upper level sensor, and the other one represents in-series connected normally closed contacts of lower level sensor and normally open contacts of direct current relay the coil of which is connected to output of rectifier bridge. To the device there introduced is time relay the coil of which is parallel connected to the coil of direct current relay, and normally closed contact of time relay is connected to normally open contact of direct current relay, parallel normally closed contact of lower level sensor.

EFFECT: higher reliability of device owing to using the protection of electric motor against emergency operating mode at break of control wire connecting the lower level sensor to control circuit.

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