Mm3 Sequences - GE MM3 Instruction Manual

9.7 AUTOTRANSFORMER OPEN TRANSITION STARTER 9 STARTER TYPES

9.7.2 MM3 SEQUENCES

START (CONTACTOR SEQUENCE set to 1S-2S) sequence:
1. Start command received by the MM3 (serial, switch input or faceplate).
2. Close and maintain Contactor A output relay – close 1S contactor.
3. Wait 20 ms, close and maintain Aux. 1 output relay – power is applied to the autotransformer.
4. Wait for the time set in the CHANGE OVER TIME setpoint.
5. Open Contactor A and Aux. output relays.
6. Wait 20 ms.
7. Close and maintain Contactor B output relay.
START (CONTACTOR SEQUENCE set to 2S-1S) sequence:
1. Start command received by the MM3 (serial, switch input or faceplate).
2. Close and maintain Aux. 1 output relay – power is applied to the autotransformer.
3. Wait 20 ms, close and maintain Contactor A output relay – close the 1S contactor.
4. Wait for the time set in the CHANGE OVER TIME setpoint.
5. Open Contactor A and Aux. output relays.
6. Wait 20 ms.
7. Close and maintain Contactor B output relay.
STOP/TRIP sequence:
1. Stop command received by the MM3 or a trip occurs.
2. Open Contactor B output relay.
If feedback is not received from the 1S, 2S or R contacts to the Contactor A, B or auxiliary relay Status N.O.
inputs within one second of closing Contactors A, B or the auxiliary relay, an OPEN CONTROL CIRCUIT alarm
will occur. This will cause Contactors A, B and the auxiliary relay to open.
If feedback remains at any of the Status N.O. inputs for more than one second after opening the its respective
relay, a WELDED CONTACTOR alarm will occur.
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9-20 MM3 Motor Manager 3 GE Power Management