ABB Relion 620 Series - Page 718

4.6.2.6 Signals
Table 675: LSHDPFRQ Input signals
Name Type Default Description
F SIGNAL 0 Measured frequency
dF/dt SIGNAL 0 Rate of change of fre-
quency
BLOCK BOOLEAN 0=False Block signal for acti-
vating the blocking
mode
BLK_REST BOOLEAN 0=False Block restore
MAN_RESTORE BOOLEAN 0=False Manual restore signal
Table 676: LSHDPFRQ Output signals
Name Type Description
OPERATE BOOLEAN Operation of load shedding
OPR_FRQ BOOLEAN Operate signal for under fre-
quency
OPR_FRG BOOLEAN Operate signal for high df/dt
START BOOLEAN Start
ST_FRQ BOOLEAN Pick-Up signal for under fre-
quency detection
ST_FRG BOOLEAN Pick-Up signal for high df/dt
detection
RESTORE BOOLEAN Restore signal for load re-
storing purposes
ST_REST BOOLEAN Restore frequency attained
and restore timer started
4.6.2.7 Settings
Table 677: LSHDPFRQ Group settings (Basic)
Parameter
Values (Range) Unit Step Default Description
Load shed mode
1=Freq<
6=Freq< OR df/dt
8=Freq< AND df/dt
1=Freq< Set the operation
mode for load
shedding function
Restore mode
1=Disabled
2=Auto
3=Manual
1=Disabled Mode of operation
of restore function-
ality
Start value Freq 0.800...1.200 xFn 0.001 0.975 Frequency set-
ting/start value
Start value df/dt -0.200...-0.005 xFn /s 0.005 -0.010 Setting of frequen-
cy gradient for
df/dt detection
Table continues on the next page
Protection functions 1MRS757644 H
718 620 series
Technical Manual