9-4 MM2 Motor Manager 2
GE Power Management
9.2 FV REVERSING STARTER 9 STARTER TYPES
9
9.2.2 MM2 SEQUENCES
START:
1. Start A command received by the MM2 (serial, switch input or faceplate).
2. Close and maintain Contactor A output relay – the motor is now across the line in the forward
direction.
STOP/TRIP:
1. Stop command received by the MM2 or a trip occurs.
2. Open the currently closed Contactor output relay – the motor stops.
REVERSE (if the motor is running in the forward direction):
1. Start B command is received by the MM2 (serial, switch input or faceplate).
2. Open Contactor A relay – the motor is now off line
3. Wait the required transfer time.
4. Close and maintain Contactor B output relay – the motor is now across the line in the reverse
direction.
9.2.3 NOTES
All output relays de-energize when the MM2 power is interrupted, causing them to open and stop the
motor. The MM2 can only be wired for fail-safe operation.
If used, the VT input must have a separate PT so that the current and voltage inputs remain in phase
regardless of which direction the motor is running. See Figure 9–4: FV REVERSING STARTER on
page 9–5.
If feedback is not received from either the F or the R contactor to Contactor Status N.O. inputs within
one second of closing Contactor A or B output relays, an OPEN CONTROL CIRCUIT alarm will
occur. This will cause the currently closed relay to open.
If feedback remains at the Contactor (A or B) Status N.O. input more than one second after opening
Contactor A or B output relays, a WELDED CONTACTOR alarm will occur.
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