- COMPL_FAST
- COMPL_FBBM
- COMPL_1ST_PH
- COMPL_RES
- COMPL_TDLY
If feeder 1 is the standby feeder, then OPEN_CB2 is activated if:
• transfer is allowed from feeder 2 to feeder 1
• transfer is not started by CB open transfer
• transfer is running, i.e. one or more transfers are active
CLOSE_CB1 is activated if:
• transfer is allowed from feeder 2 to feeder 1
• transfer is completed, this is indicated with following signals:
- COMPL_FAST
- COMPL_FBBM
- COMPL_1ST_PH
- COMPL_RES
- COMPL_TDLY
9.12.5.6 Load shedding
The load-shedding action can be performed based on various load shedding modes
during transfer action.
OPR_LOADSHED
Load
shedding
U_AB_BB
(from Voltage monitoring)
TR_RUNNING
(from Bus transfer)
Figure 947: Load shedding module diagram
The OPR_LOADSHED output is TRUE if any of the following conditions are satisfied:
• Instantaneous: If the transfer is active (TR_RUNNING is TRUE), and
Load
shedding mode
setting is “Instantaneous”, the OPR_LOADSHED will be TRUE.
Load shedding is not activated during fast transfer.
• Voltage based: If the TR_RUNNING signal is TRUE, and
Load shedding mode
setting is “Voltage based” and busbar voltage is less than
Loadshed V limit
.
• Time based: If the TR_RUNNING signal is TRUE, and
Load shedding mode
setting
is “Time based” and the fast transfer is not active (FAST_READY is FALSE), the
OPR_LOADSHED is TRUE after
Loadshed time delay
setting parameter value.
If
Load shedding mode
setting is “None”, the OPR_LOADSHED output remains FALSE.
9.12.5.7 Circuit breaker monitoring
Breaker closing time is essential information for the function, especially the 1
st
phase transfer needs accurate information of the circuit breaker closing time in
1MRS759142 F
Control functions
REX640
Technical Manual
1781
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