ABB SPAF 140 C User Manual And Technical Description page 10

10
Four protection stages, two signalling and two
tripping, are used in the example described.
Stage 2 produces an alarm signal, if the fre-
quency exceeds the rated frequency, and stage
3, correspondingly, if the frequency falls below
the rated frequency. The selected alarm limits
allow the generator and the turbine to operate
for a long time with the concerned frequency,
without any risk of being damaged.
Stage Operate
value (Hz)
1 53.0
2 51.5
3 48.5
4 47.0
*)The trip contact TS2 is used for underfrequency alarm, because only one trip contact is
required for the protection.
Fig. 5. Setting of the protection stages of frequency relay SPAF 140 C used for the protection of a
generator and a turbine.
In the case described in the example the switches of the frequency relay SPAF 140 C can be set as
follows:
Setting of t, relay module SPCF 1D15
Switch- Serial comm. Checksum Operation
group parameter
SGF1 S84
SGF2 S85
SGF3 S86
SGF4 S87
SGF5 S88
SGF6 S89
SGF7 S90
SGB1 S91
SGB2 S92
SGB3 S93
SGB4 S94
SGB5 S95
SGB6 S96
SGR1 S97
SGR2 S98
SGR3 S99
SGR4 S100
SGR5 S101
SGR6 S102
SGR7 S103
SGR8 S104
SGR9 S105
Should the frequency decrease or increase to a
dangerous level, the relay provides a trip signal.
The protection also includes a blocking input
which can be used for blocking the relay opera-
tion, for instance, during the start of the gen-
erator.
The start values and operate times of the pro-
tection stages and the timers controlling the in-
dividual circuit breakers are shown in Fig. 5.
The designations used in Fig. 5 refer to Fig. 4.
Delay Timer Relay output
0.30 t
1
1.00 t
2
1.00 t
3
0.30 t
4
1 Only frequency function
1 Only frequency function
1 Only frequency function
1 Only frequency function
255 Outputs continuously operated
2 TS1 connected to LED indicator TRIP
0 U = 100 V
n
15 Blocking via external control signal BS1
0 External control signal BS2 not in use
0 External control signal BS3 not in use
0 External control signal BS4 not in use
0 External control signal BS5 not in use
15 Undervoltage blocking to all stages
2 Overfrequency trip signal to trip contact TS1
0 Not in use
1 Underfrequency alarm signal to signal contact SS1
0 Not in use
8 Underfrequency alarm signal to trip contact TS2
0 Not in use
2 Underfrequency trip signal to trip contact TS1
0 Not in use
0 No recovery function
Function
TS1 Tripping
SS1 Overfrequency alarm
TS2 * Underfrequency alarm
TS1 Tripping