ABB RELION 620 Series Technical Manual page 722

Section 4
Protection functions
4.6.2.6
4.6.2.7
Table 677: LSHDPFRQ Group settings (Basic)
Parameter
Load shed mode
Restore mode
Start value Freq
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Table 674: Setting for a five-step restoring operation
Load-shedding steps
1
2
3
4
5
Signals
Table 675: LSHDPFRQ Input signals
Name
F
dF/dt
BLOCK
BLK_REST
MAN_RESTORE
Table 676: LSHDPFRQ Output signals
Name
OPERATE
OPR_FRQ
OPR_FRG
START
ST_FRQ
ST_FRG
RESTORE
ST_REST
Settings
Values (Range) Unit
1=Freq<
6=Freq< OR df/dt
8=Freq< AND df/dt
1=Disabled
2=Auto
3=Manual
0.800...1.200 xFn
Restoring start Val setting
0.990 · Fn (49.5 Hz)
0.990 · Fn (49.5 Hz)
0.990 · Fn (49.5 Hz)
0.990 · Fn (49.5 Hz)
0.990 · Fn (49.5 Hz)
Type Default Description
SIGNAL 0 Measured frequency
SIGNAL 0 Rate of change of frequency
BOOLEAN 0=False Block signal for activating the blocking mode
BOOLEAN 0=False Block restore
BOOLEAN 0=False Manual restore signal
Type Description
BOOLEAN Operation of load shedding
BOOLEAN Operate signal for under frequency
BOOLEAN Operate signal for high df/dt
BOOLEAN Start
BOOLEAN Pick-Up signal for under frequency detection
BOOLEAN Pick-Up signal for high df/dt detection
BOOLEAN Restore signal for load restoring purposes
BOOLEAN Restore frequency attained and restore timer
started
Step Default
1=Freq<
1=Disabled
0.001 0.975
1MRS757644 F
Restore delay time setting
200000 ms
160000 ms
100000 ms
50000 ms
10000 ms
Description
Set the operation mode for load shedding
function
Mode of operation of restore functionality
Frequency setting/start value
Technical Manual
620 series