
Load-shedding steps
Restore start Val setting
Restore delay time setting
4
0.990 · Fn (49.5 Hz)
50000 ms
5
0.990 · Fn (49.5 Hz)
10000 ms
4.6.2.7
Signals
LSHDPFRQ Input signals
Table 896: LSHDPFRQ Input signals
Name
Type
Default
Description
U3P
SIGNAL
-
Three-phase voltages
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
LSHDPFRQ Output signals
Table 897: 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 restor-
ing purposes
ST_REST
BOOLEAN
Restore frequency attained
and restore timer started
4.6.2.8
LSHDPFRQ Settings
Table 898: LSHDPFRQ Group settings (Basic)
Parameter
Values (Range)
Unit
Step
Default
Description
Load shed mode
1=Freq<
6=Freq< OR df/dt
1=Freq<
Set the operation
mode for load
shedding function
Table continues on the next page
Protection functions
1MRS759142 F
938
REX640
Technical Manual