GE 489 - Manual (Page 114)

4-64 489 Generator Management Relay GE Multilin
4.10 S9 THERMAL MODEL 4 SETPOINTS
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
489
VOLTAGE DEPENDENT
OVERLOAD PROTECTION at 80% V
808830A3.CDR
1
1 2 3 4 5 6 7 8
2
3
4
5
6
7
8
9
10
20
30
40
50
60
70
80
90
100
T
IM
E
TO
T
R
IP
(S
E
C
O
N
D
S
)
MULTIPLES OF FULL LOAD AMPS
200
300
400
500
600
700
800
900
1000
GE Multilin
489
VOLTAGE DEPENDENT
OVERLOAD PROTECTION at 100% V
808829A3.CDR
1
1 2 3 4 5 6 7 8
2
3
4
5
6
7
8
9
10
20
30
40
50
60
70
80
90
100
T
IM
E
TO
T
R
IP
(S
E
C
O
N
D
S
)
MULTIPLES OF FULL LOAD AMPS
200
300
400
500
600
700
800
900
1000
GE Multilin