GE 489

4-60 489 Generator Management Relay
GE Power Management
4.10 S9 THERMAL MODEL 4 SETPOINT PROGRAMMING
4
The following curves illustrate the resultant overload protection for 80% and 100% voltage, respectively. For voltages inbe-
tween these levels, the 489 shifts the acceleration curve linearly and constantly based upon the measured voltage during
generator start.
Figure 4–16: VOLTAGE DEPENDENT O/L PROTECTION AT 80% AND 100% VOLTAGE
808830A2.CDR
1
123 45678
2
3
4
5
6
7
8
9
10
20
30
40
50
60
70
80
90
100
TIME TO TRIP (SECONDS)
MULTIPLES OF FULL LOAD AMPS
200
300
400
500
600
700
800
900
1000
489
VOLTAGE DEPENDENT OVERLOAD
PROTECTION AT 80% V
GE Power Management
808829A2.CDR
1
123 45678
2
3
4
5
6
7
8
9
10
20
30
40
50
60
70
80
90
100
TIMET OTRIP (SECONDS)
MULTIPLES OF FULL LOAD AMPS
200
300
400
500
600
700
800
900
1000
489
TVOL AGE DEPENDENT OVERLOAD
PROTECTION AT 100% V
GE Power Management