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4 PROGRAMMING
Table 4–2: 239 PHASE OVERLOAD TRIP TIMES (SECONDS)
CURVE
NUMBER
1.03
1.05
1
1437
854
2
2874
1707
3
4311
2561
4
5748
3415
5
7184
4269
6
8621
5122
7
10058
5976
8
11495
6830
9
12932
7683
10
14369
8537
11
15806
9391
12
17243
10245
13
18680
11098
14
20116
11952
15
21553
12806
b) PHASE S/C
•
PHASE S/C TRIP: In any application where the available short circuit current is above the inter-
rupting capability of the contactor, short circuit currents must cause a fuse or circuit breaker to
operate. This prevents damage to the contactor which is not designed to interrupt normal levels
of short circuit current. In an application with fuses, program the setpoint
&855(17?3+$6( 6&?3+$6( 6?& 75,3 2)) to prevent the contactor from attempting to trip during a
short circuit.
If a circuit breaker which can be tripped by an external contact closure is available upstream from
the contactor, it is possible to program the setpoint 6 3527(&7,21?3+$6( &855(17?3+$6( 6
&?3+$6( 6?& 75,3 $8;,/,$5< to cause a short circuit to activate the auxiliary relay instead of the trip
relay. Though, it is also possible to activate both the trip & auxiliary relays simultaneously. The
auxiliary relay could then be connected to the upstream breaker to cause it to open for a short cir-
cuit. Ensure that the auxiliary relay is only programmed to activate under short circuit when used
in this manner.
SPECIAL NOTE: The AUXILIARY and TRIP status indicators will both operate for these trips
even if the TRIP relay is not selected for use (i.e. AUXILIARY). If the breaker cannot be externally
tripped, program the setpoint 6 3527(&7,21?3+$6( &855(17?3+$6( 6&?3+$6( 6?& 75,3 2)) to pre-
vent the contactor from attempting to trip during a short circuit. If a breaker is used as the motor
starter interrupting device, short circuit protection would generally be enabled as it will normally
be capable of handling the fault current. Short circuit protection causes the breaker to open
quickly to prevent excessive mechanical damage or fire due to any large phase current. Com-
plete protection from phase-to-phase and phase-to-ground faults is provided with this feature.
GE Multilin
Courtesy of NationalSwitchgear.com
MULTIPLE OF MOTOR FULL LOAD CURRENT
1.1
1.5
2
2.5
416.7
70.0
29.2
16.7
833.4
140.0
58.3
33.3
1250.0
210.0
87.5
50.0
1666.7
280.0
116.6
66.6
2083.4
349.9
145.8
83.3
2500.1
419.9
174.9
100.0
2916.8
489.9
204.1
116.6
3333.5
559.9
233.3
133.3
3750.1
629.9
262.4
149.9
4166.8
699.9
291.6
166.6
4583.5
769.9
320.7
183.3
5000.2
839.9
349.9
199.9
5416.9
909.9
379.1
216.6
5833.5
979.9
408.2
233.2
6250.2 1049.8
437.4
249.9
239 Motor Protection Relay
3
4
5
6
10.9
5.8
3.64
2.50
21.9
11.7
7.29
5.00
32.8
17.5
10.93
7.49
43.7
23.3
14.57
9.99
54.7
29.1
18.22
12.49
65.6
35.0
21.86
14.99
76.5
40.8
25.50
17.49
87.5
46.6
29.15
19.98
98.4
52.5
32.79
22.48
109.3
58.3
36.43
24.98
120.3
64.1
40.08
27.48
131.2
70.0
43.72
29.98
142.1
75.8
47.36
32.48
153.0
81.6
51.01
34.97
164.0
87.4
54.65
37.47
4 PROGRAMMING
8
10
11
1.39
0.88
0.73
2.78
1.77
1.46
4.16
2.65
2.19
5.55
3.53
2.91
6.94
4.42
3.64
8.33
5.30
4.37
9.71
6.18
5.10
11.10
7.06
5.83
12.49
7.95
6.56
13.88
8.83
7.29
15.27
9.71
8.01
16.65
10.60
8.74
18.04
11.48
9.47
19.43
12.36
10.20
20.82
13.25
10.93
6 3527(&7,21?3+$6(
4-23
4
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