Autotransformer Open Transition Starter - GE MM300 Instruction Manual

CHAPTER 5: SETPOINTS
Autotransformer open
transition starter
MM300 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL
Pre-Contactor Time
Range: 0 to 60 seconds in steps of 1
Default: 0 seconds
This setpoint specifies the time after a start command before the motor is started. Most
starters do not use this delay for forced starts such as 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 pre-contactor function.
Ramp Up Time
Range: 0 to 125 seconds in steps of 1
Default: 1 second
This setpoint specifies the time after signalling the soft starter to ramp up that the up-to-
speed feedback can be delayed without issuing a Drive Start Fail alarm.
Ramp Down Time
Range: 0 to 125 seconds in steps of 1
Default: 1 second
This setpoint specifies the time after signalling the soft starter to ramp down before the
main contactor is opened, cutting power to the starter. If speed feedback is still on when
this time expires, a Drive Stop Fail alarm is issued.
The following table shows the I/O names used in Autotransformer open transition starter. It
also shows connections between contactor, inputs/outputs and internal flags/operands
driving these outputs.
FlexLogic operand Contact output
Contactor A Relay C1
Contactor B Relay C3
Contactor C Relay Assignable (default: N/A)
Autotransformer open transition starter is a reduced voltage starter.
The expansion I/O module type C, D or E must be properly installed when the
Autotransformer open transition starter is used. Three motor contactors R, 1S and 2S each
controlled by a separate MM300 output relay are used to perform this function. There are
two options of this starter: 1S-2S and 2S-1S. Each one offers a slightly different sequence
of contactors operation. The description of both sequences is given as follows:
1S-2S start sequence:
1. Start A command received by the MM300 (serial, digital input or faceplate).
2. Wait for the time set in the Pre-Contactor Time setpoint.
3. Close and maintain contactor 1S.
4. Wait until contactor 1S closed status is received, then close and maintain contactor
2S. Reduced voltage is applied to the motor.
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.
2S-1S start sequence:
1. Start A command received by the MM300 (serial, digital input or faceplate).
2. Wait for the time set in Pre-Contactor Time setpoint.
CONFIGURATION SETPOINTS
Contactor Status contact input
1S C5
R C6
2S Assignable (default: N/A)
5–13