Two-Speed Starter - GE MM300 Instruction Manual

CONFIGURATION SETPOINTS

Two-speed starter

5–8
Figure 5-6: 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.
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 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
Transfer Time to allow the motor to slow. When the transfer time timer times out, the
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).
The pre-contactor is omitted on forced starts (for example, undervoltage restart immediate
or external start). 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
MM300 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
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853718A1.CDR