Appendix D: Optional equipment
74
SC9000 EP medium voltage drives
IB020001EN—February 2016
www.eaton.com
Figure 74. Selected motor on utility bus
4.
Sync Down
●
When instructed by the supervisory control, the PLC
sends a command to the AFD to “Sync Down”
●
The PLC commands the AFD to start
●
With the AFD output contactor open and the selected
motor’s bypass contactor closed, the PLC closes the
selected motor’s motor select contactor (
Figure 75
)
Figure 75. Motor select contactor closes
●
The AFD is commanded to match the utility’s voltage,
frequency and phase angle; once this is completed, the
AFD output contactor closes and the selected motor’s
utility’s bypass contactor opens. The AFD output reactor
dampens any transient currents that may occur during the
transition (
Figure 76
)
Figure 76. AFD contactor closes, bypass opens
●
The AFD, now connected to the selected motor, operates
at a set speed or follows a reference speed (
Figure 77
)
Figure 77. Selected motor runs on AFD bus
Control interface
Customer commands for each motor include Start, Stop,
Sync Up, Sync Down, and Run Speed. Motor and Contactor
status are available for supervisory control.
Control options
The SC9000 EP Synchronous Transfer system comes
standard with Eaton Programmable Controllers. Other
controllers can be furnished as an option.
Control application configuration
The SC9000 EP medium voltage drives application has
programming parameters for use with Synchronous Transfer
systems. Refer to Chapter 5, Parameter Group G1.17 for
detailed information on these parameters.
Fault conditions / alarm states
The SC9000 EP monitors fault conditions and alarm states
for all Synchronous Transfer system elements. Individual
motor PLCs monitor motor and contactors’ status and
coordinate with the Drive master PLC at all times. Drive
status and alarm conditions are available through the
SC9000 EP operator interface and remote supervisory
control interface provisions.
O&M technical references
For additional information about the Synchronous Transfer
system elements, refer to this SC9000 EP User Manual,
IB02004001E and your project O&M Manual references:
AD02004001E
Synchronous Transfer Control with
SC9000 EP
Summary of Contents for SC9000 EP
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