Rockwell Automation 7763 Medium Voltage OneGear SMC Flex Motor Controller (10-15 kV) - Manual (Page 44)

44 Rockwell Automation Publication 7760-UM001D-EN-P - October 2014
Chapter 1 Product Overview
Functional Description Bulletin 7763 – Basic Control – Controlled Start only
When wired as shown in Figure 25 on page 45 , the controller operates as follows:
Pressing the "Start" button initiates the start sequence. Relay "-KG1" closes and
applies control power to terminal 17 of the SMC Flex module. The auxiliary
contact #4 (set for "normal") closes, picking up "-KG3", which completes the
hold-in circuit on the start button, and closes the Start Breaker.
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 "-KG2", which closes the
bypass breaker. The motor then runs at full line voltage.
When the "Stop" button is pressed, the "-KG1" relay opens terminal 17 on the
SMC Flex module. The "AUX4" and "AUX1" contacts open, which opens the
start and bypass breakers, allowing the motor to stop.
Bulletin 7760 – Basic Control – Controlled Start Only
The Bulletin 7760 is intended for addition to an existing motor controller, which
provides circuit isolation, motor switching, and overload and overcurrent
protection. When wired as shown in
Figure 26 , the controller operates as follows:
When a start is initiated in the existing motor controller and the contactor (or
breaker) closes, a contact must be supplied to tell the 7760 to start also. A "-KG1"
contact will apply control voltage to terminal 17 of the SMC Flex module.
When stopping the motor, the contactor in the existing controller will open,
removing power from the motor, and then the "-KG1" relay. The "AUX1" contact
(External Bypass) is held closed for 10 seconds to keep the bypass contactor
closed for a short time.
The “Fault” contact on the SMC Flex module should be wired into the existing
controller to trip the main contactor (or breaker) in the event of a fault condition
sensed by the SMC Flex module.
If possible, it is better to have the SMC Flex module control the main contactor
(or breaker) directly. In this case, the control circuit would look like, and function
similar to, the descriptions above for the Bulletin 7763.