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All about Motors
Direct-on-line start of three-phase motors |
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| Reversing and two speeds (reversing contactor) |
| Special circuit (tapped winding) for feed drives, etc. |
FORWARD: feed or high speed
RETRACT: high speed only
STOP: tapped winding |
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0: Stop
I = Low speed – FORWARD (Q17)
II = High speed – FORWARD (Q21 + Q23)
III = High speed – FORWARD (Q22 + Q23)
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Q17: Feed forward
Q21: High speed forward
Q23: Star contactor
K1: Contactor relay
Q22: Retract high speed
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Method of operation: Forward travel is initiated by pressing pushbutton I or II according to the speed
required. Pushbutton I switches on the feed motion via Q17. Q17 maintains itself via its normally open contact 13-14. If the feed
movement is to occur at high speed star contactor Q23 is energized via pushbutton II which energizes the high speed contactor Q21 via its
normally open contact Q23/13-14. Both of the contactors are maintained via Q21/13-14. A direct switch over from feed to high-speed during the
process is possible.
High speed reverse is initiated by pushbutton III: Contactor relay K1 picks up and energizes star contactor Q23 via K1/14-13. High-speed
contactor Q22 is energized via the normally open contacts, K1/43-44 and Q23/44-43, and are maintained via Q22/14-13. The reverse action can only
be stopped via pushbutton 0. Direct changeover/reversal is not possible.
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