Mm3 Sequences - GE MM3 Instruction Manual

9.4 SLIP RING STARTER 9 STARTER TYPES

9.4.2 MM3 SEQUENCES

START sequence:
1. The start command is received by the MM3 (serial, switch input, or faceplate).
2. Close and maintain Contactor A relay – the motor is now starting with the secondary resistors in circuit.
3. Wait STAGE ONE SHORTING TIME delay.
4. Close and maintain Contactor B relay – the motor is now running with the secondary resistors shorted out.
STOP/TRIP sequence:
1. Stop command received by the MM3 or a trip occurs.
2. Open Contactor A and B output relays.
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 S or R contacts to the Contactor A or B Status N.O. inputs within one sec-
ond of closing Contactor A or B output relays, an OPEN CONTROL CIRCUIT alarm will occur. This will cause
Contactor A and B output relays to open. If feedback remains at the Contactor A or B Status N.O. input more
than one second after opening the Contactor A or B output relays, a WELDED CONTACTOR alarm will occur.
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9-12 MM3 Motor Manager 3 GE Power Management