Rockwell Automation 1402-LSM Line Synchronization Module Installation Instructions - Manual (Page 39)

Chapter 4
Application Information
4–5
Discrete Outputs From The PLC–5 Continued
present, the synchronization fails and the “Synchronization Failure” discrete
input to the PLC–5 will be asserted. Additional information pertaining to the
cause of the failure may be obtained by reading the appropriate block transfer
data from the “Synchronizing Bus Error Parameters” table. (See Appendix B,
“Block Transfer and Discrete I/O Definition”, for additional information.)
The Auto Synchronization Mode discrete output from the PLC–5 causes the
LSM to issue the appropriate error signals, both continuous discrete inputs to
the PLC–5 and via block–transfer, to cause via the PLC–5 the alternator
voltage, frequency, and phase to align with the Reference Bus. Once these
conditions are satisfied, the Close Breaker discrete input to the PLC–5 will
be asserted based on the synchronization configuration.
The Check Synchronization Mode discrete output from the PLC–5 causes the
LSM to function in the same manner as the Auto Synchronization Mode
output from the PLC–5, except it will not assert the Close Breaker discrete
input to the PLC–5. This mode is useful for testing the system.
The Permissive Synchronization discrete output from the PLC–5 will not
cause the LSM to issue any error signals, but it will assert the Close Breaker
discrete input to the PLC–5 if the synchronization criteria are satisfied.
The Load Share Disable discrete output from the PLC–5 when set to 1 will
cause the load share function of the LSM to be disabled.
The Isochronous/Droop Mode discrete output from the PLC–5 when set to 1
indicates Isochronous mode of load share operation. If this output from the
PLC–5 is cleared to 0 the LSM will operate in the droop mode of load share.
While the LSM is in Droop mode, all load share errors and discrete inputs to
the PLC–5 will be set to 0. The load share terminals on the front of the
module will be disconnected from internal circuitry, therefore, the load share
function is effectively disabled.
The Enable Single Phase Synchronization discrete output from the PLC-5,
when set to 1, allows the synchronization function to ignore the V1 and V2
inputs. In this mode, phase rotation mismatch does not cause a
synchronization failure, and the V1 and V2 inputs are not used for features
such as dead-bus detect or over-voltage detection. This mode allows
connection of the V3 inputs to single phase systems, or those systems with a
single transformer per 3-phase system.
Interfacing to the LSM Continued