Contactor Circuits

5. Contactor Circuits

5.1. Types of Excitation of the Control

Self-excitation

Advantage: no-voltage characteristic

Figure

Separate excitation

Figure

The contactor circuits are provided with permanent contact making

Control current locking

Advantage: By means of the control current locking contactor, no-voltage characteristic is attained in separately excited contactor circuits.

5.2. Possibilities of Representing Contactor Circuits

pulse contact making functional diagram

mixed representation - main circuit (single-pole); control circuit (all-pole)

control circuit - shown in the form of a circuit diagram

sequential circuit - functional diagram

Circuit diagram for the control of the sequential circuit

Sequential circuit with rotation monitors and unlocking switches

Circuit diagram for the sequential circuit with rotating monitors and unlocking switches

5.3. Reversing Contactor Circuits

control current - pulse locking

Circuit diagrams for reversing contactor circuits (pulse locking)

To be used for single drives only, circuit is not safe!

Circuit diagrams for reversing contactor circuits (pulse and holding current locking)

reversing contactor circuit - push - button locking

Circuit diagrams for reversing contactor circuits (Push-button locking)

Circuit diagrams for reversing contactor circuits (Push-button locking arranged as rapid change-over circuit; suitable for smaller motors only)

Reversing contactor circuit with star-delta starting main circuit

Circuit diagram for the control of the reversing contactor circuit with star-delta starting

5.4. Arc Extinguishing Circuits

reversing contactor - rapid changing-over

Arc extinguishing circuit for separate excitation

Circuit diagram for the control of the separately escited arc extinguishing circuit

5.5. Three-contactor Star-delta Connection

main circuit

Circuit diagram for the control of the three-contactor star-delta connection

5.6. Squirrel-cage Induction Motor

with effective resistance for starting in the stator and self-monitoring (unsymmetric circuit)

Circuit diagram for the control of the starting action with effective resistance

5.7. Sliping Rotor

with rotor contactor starter

Circuit diagram for the control of the slip-ring rotor with rotor starter

5.8. Interference Suppression

Interference suppression of a universal motor

Interference suppression of a direct-current shunt motor

Interference suppression of switch gears

Interference suppression of electric bells (A)

Interference suppression of electric bells (B)

5.9. Light-current Controlled Power Plant with Impulse Relay

Figure

Figure

Figure