GE Multilin 489 Instruction Manual page 186
Generator management relay
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Also See for Multilin 489:
- Instruction manual (306 pages) ,
- Communications manual (78 pages) ,
- Instruction manual (259 pages)
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(× FLA)
× 1
× 2
× 3
6.0
2.50
5.00
7.49
0
6.5
2.12
4.24
6.36
0
7.0
1.82
3.64
5.46
0
7.5
1.58
3.16
4.75
0
8.0
1.39
2.78
4.16
0
10.
1.39
2.78
4.16
00
15.
1.39
2.78
4.16
00
20.
1.39
2.78
4.16
00
5–76
Courtesy of NationalSwitchgear.com
Table 5–7: 489 Standard Overload Curve Multipliers
STANDARD CURVE MULTIPLIERS
× 4
× 5
× 6
× 7
9.99
12.4
14.9
17.4
9
9
9
8.48
10.6
12.7
14.8
0
2
4
7.29
9.11
10.9
12.7
3
5
6.33
7.91
9.49
11.0
8
5.55
6.94
8.33
9.71
5.55
6.94
8.33
9.71
5.55
6.94
8.33
9.71
5.55
6.94
8.33
9.71
Custom Overload Curve
If the induction generator starting current begins to infringe on the thermal damage
curves, it may become necessary to use a custom curve to tailor generator protection so
successful starting may be possible without compromising protection. Furthermore, the
characteristics of the starting thermal (locked rotor and acceleration) and the running
thermal damage curves may not fit together very smoothly. In this instance, it may be
necessary to use a custom curve to tailor protection to the thermal limits to allow the
generator to be started successfully and utilized to its full potential without compromising
protection. The distinct parts of the thermal limit curves now become more critical. For
these conditions, it is recommended that the 489 custom curve thermal model be used.
The custom overload curve allows users to program their own curves by entering trip
times for 30 pre-determined current levels.
The curves below show that if the running overload thermal limit curve were smoothed
into one curve with the locked rotor thermal limit curve, the induction generator could not
be started at 80% voltage. A custom curve is required.
× 8
× 9
× 10
× 11
19.9
22.4
24.9
27.4
9
8
8
8
16.9
19.0
21.2
23.3
6
8
0
2
14.5
16.3
18.2
20.0
7
9
1
4
12.6
14.2
15.8
17.4
6
4
2
1
11.1
12.4
13.8
15.2
0
9
8
7
11.1
12.4
13.8
15.2
0
9
8
7
11.1
12.4
13.8
15.2
0
9
8
7
11.1
12.4
13.8
15.2
0
9
8
7
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
× 12
× 13
× 14
× 15
29.9
32.4
34.9
37.4
8
8
7
7
25.4
27.5
29.6
31.7
4
5
7
9
21.8
23.6
25.5
27.3
6
8
0
2
18.9
20.5
22.1
23.7
9
7
5
4
16.6
18.0
19.4
20.8
5
4
3
2
16.6
18.0
19.4
20.8
5
4
3
2
16.6
18.0
19.4
20.8
5
4
3
2
16.6
18.0
19.4
20.8
5
4
3
2
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