Two-Speed Starter - GE MM200 Instruction Manual

CHAPTER 4: SETPOINTS

Two-speed starter

MM200 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL
Figure 4-3: Typical starter timing for full-voltage reversing starter
Motor current
Contactor A relay
Contactor B relay
Pre-contactor
Starting
Running
The following additional setpoints are available for the full-voltage reversing starter.
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. 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.
Transfer Time
Range: 0 to 125 seconds in steps of 1
Default: 1 second
This setpoint represents the time between stopping and starting in a new direction for
the reversing starter.
The "Two Speed" starter type is a full-voltage or across-the-line two speed starter.
When a start A (low speed) control is received, the pre-contactor relay (if any) is picked up
for the set
Pre-Contactor Time
relay picks up and seals-in, starting the motor in low speed. When a start B (high speed)
control is received, the A contactor is dropped out. When contactor A status Off is received,
the contactor B relay picks up and seals-in, starting the motor in high speed. Should a start
A (low speed) control be received when the high speed contactor B is picked up, contactor
B is dropped out. When contactor B status Off is received, the starter waits for the set
to allow the motor to slow. When the transfer time timer times out, the
Transfer Time
contactor A relay picks up and seals-in, starting the motor in low speed. When a stop
control is received, the contactor A and B relays are dropped out and the motor stops.
If the
High Speed Start Block
speed) control unless already running on contactor A (low speed).
Forced starts are not supervised by this starter transfer timer – any external starting circuit
must itself respect high to low speed transition restrictions and starting in high speed
restrictions.
The following figure illustrates typical starter timing beginning from the stopped state.
T
P
P = Pre-contactor time setting
T = Transfer time setting
. When the pre-contactor timer times out, the contactor A
setpoint is "Enabled", this starter will not allow a start B (high
CONFIGURATION SETPOINTS
T
888718A1.CDR
4–5