GE MM300 Instruction Manual page 124

CONFIGURATION SETPOINTS
5–14
3. Close and maintain contactor 2S. Reduced voltage is applied to the motor.
4. Wait until contactor 2S closed status is received, then close and maintain contactor
1S.
5. Wait for the time set in the Transfer Time setpoint.
6. Open contactors 1S and 2S.
7. Wait until contactor 1S open status is received.
8. Close and maintain contactor R. Full voltage is applied to the motor.
Stop/trip sequence:
1. Stop command received by the MM300 or a trip occurs.
2. Open Contactor R.
3. Open Contactors 1S and 2S if they are not already opened.
The following figures illustrate typical starter timing beginning from the stopped state.
Figure 5-11: Typical starter timing for autotransformer open transition starter 1S-2S
Figure 5-12: Typical starter timing for autotransformer open transition starter 2S-1S
Pre-Contactor Time
Range: 0 to 60 seconds in steps of 1
Default: 0 seconds
This setpoint represents the time after a start command before the motor is started.
Most starters do not use this delay for forced starts such as undervoltage restart
immediate and external start. This setpoint is also used by the inverter starter and the
soft start starter to set the amount of time between powering up an inverter or soft
starter and sending the ramp-up command. An audible or other warning signal can be
activated in this interval by connecting the signal to a contact output set to the
precontactor function.
MM300 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS