Rockwell Automation 1560E SMC Flex Smart Motor Controller - Manual (Page 38)

1-28 Product Overview
%
5-"
%.
0
Functional Description The following functional descriptions and associated control circuits are
for units using IntelliVAC contactor control modules. For units with
electromechanical (relay) control, refer to Appendix C.
Bulletin 1562E • Basic Control – Controlled Start only
When wired as shown in Figure 1.22, 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 ("Normal") closes, energizing "M-IV" and "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, energizing "B-IV", 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 "Normal" contact opens, dropping out the
main contactor, allowing the motor to stop. The "AUX1" contact 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.