Rockwell Automation 1560E SMC Flex Smart Motor Controller - Manual (Page 177)

Appendix
C
1560E and 1562E Relay Control
Functional Description
The following functional descriptions and associated control circuits are
for units using electromechanical (relay) control.
Bulletin 1562E • Basic Control – Controlled Start only
When wired as shown in Figure C.1, the controller operates as follows:
Pressing the "Start" button initiates the start sequence. Relay "CR" closes
and applies control power to terminal 17 of the SMC-Flex module. The
auxiliary contact #2 (set for "normal") closes, picking up "MC", which
completes the hold-in circuit on the start button, and closes the main
contactor.
The SMC-Flex module examines the line voltage, looks for fault
conditions, checks phase rotation, calculates zero crossing information,
and begins gating the SCRs to start the motor.
When the motor approaches rated speed, the SMC-Flex module closes the
"AUX1" (up-to-speed) auxiliary contacts, closing relay "BC", which closes
the bypass contactor. The motor then runs at full line voltage.
When the "Stop" button is pressed, the "CR" relay opens terminal 17 on
the SMC-Flex module. The "AUX2" (Normal) contact opens, dropping
out the main contactor, allowing the motor to stop. The "AUX1" contact
also opens, but "BC" is held closed for a short time by the control module.
This holds the bypass contactor closed for about 10 seconds to protect the
power electronics from any voltage transients due to opening the motor
circuits.
1560E-UM050B-EN-P - June 2013