Autotransformer starter (M102 only)
This starter type is used to control the
autotransformer unit in order to minimize voltage
drop during motor startup. Autotransformer
starter with three contactors supports motor
starting with reduced voltage, thus providing
reduced motor startup current. The starting
torque will be reduced accordingly,
Name Pin Description
CCLI X4:6 Contactor control voltage input
CCA X4:7 Contactor control A
CCB X4:8 Contactor control B
CCC X4:9 Contactor control C
DI5 (Loc/R) X1:6 Local/remote control switch input
DI6 (F_Ca) X1:7 Contactor control A feedback
DI7 (F_Cb) X1:8 Contactor control B feedback
—
Operating sequence in Autotransformer
• Motor is stopped → Start1 → CCB&CCC close →
changeover time → CCB opens & CCA closes
• Motor is running → Stop → CCA&CCB & CCC open
—
25 Control circuit for autotransformer starter
* The assigned DI and PIN code may change in actual design
Take note of changeover time and mo-
tor startup time setting
Changeover time < Motor startup time
0 4 . MOTOR STARTERS CONTROL 33