Mm3 Sequences - GE MM3 Instruction Manual

9 STARTER TYPES 9.10 WYE-DELTA OPEN TRANSITION STARTER

9.10.2 MM3 SEQUENCES

START sequence:
1. Start command received by the MM3 (serial, switch input or faceplate).
2. Close Contactor A output relay – the motor is now in a wye configuration.
3. Close Aux. output relay 1M contact.
4. Maintain 1S contactor until CHANGE OVER CURRENT or CHANGE OVER TIME initiates a transition from wye to
delta. See CHANGE OVER CURRENT and CHANGE OVER TIME descriptions above for more detail.
5. Open Contactor A output relay – change over delay 20 ms wye to delta.
6. Close and maintain Contactor B output relay – the motor is now in a delta configuration.
STOP/TRIP sequence:
1. Stop command received by the MM3 or a trip occurs.
2. Open contactor B output relay.
3. Open Aux. output relay 1M contact
When the power to the MM3 is interrupted, all output relays on the MM3 will de-energize causing them to open
and stop the motor. The MM3 can only be wired for fail-safe operation.
If feedback is not received from the Contactor A Status N.O. input within one second of closing Contactor A
relay, an OPEN CONTROL CIRCUIT alarm will occur. This will cause All starter output relays to open. If feed-
back remains at the Contactor A Status N.O. input more than one second after opening the Contactor A output
relay, a WELDED CONTACTOR alarm will occur.
If feedback is not received from the Contactor B Status N.O. input within one second of closing Contactor B
relay, an OPEN CONTROL CIRCUIT alarm will occur. This will cause All starter output relays to open. If feed-
back remains at the Contactor B Status N.O. input more than one second after opening the Contactor B output
relay, a WELDED CONTACTOR alarm will occur.
If feedback is not received from the Wye Delta 1M contact interlock input within one second of closing Contac-
tor A relay, an OPEN CONTROL CIRCUIT alarm will occur. This will cause All starter output relays to open. If
feedback remains at the Wye Delta 1M contact interlock input more than one second after opening the AUX.
output relay, a WELDED CONTACTOR alarm will occur.
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GE Power Management MM3 Motor Manager 3 9-29