5-236
M60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
GROUPED ELEMENTS
CHAPTER 5: SETTINGS
5
IEC curves
For European applications, the relay offers three standard curves defined in IEC 255-4 and British standard BS142. These
are defined as IEC Curve A, IEC Curve B, and IEC Curve C. The IEC curves are derived by the operate and reset time
equations.
Eq. 5-30
where
T = operate time (in seconds)
TDM = Multiplier setting
I = input current
I
pickup
= Pickup Current setting
K, E = constants defined in the table
t
r
= characteristic constant defined in the table
T
RESET
= reset time in seconds (assuming energy capacity is 100% and
RESET
is “Timed”)
Table 5-28: IEC (BS) inverse time curve constants
Table 5-29: IEC curve trip times (in seconds)
IEEE Very Inverse
0.5
8.090
3.514
1.471
0.899
0.654
0.526
0.450
0.401
0.368
0.345
1.0
16.179
7.028
2.942
1.798
1.308
1.051
0.900
0.802
0.736
0.689
2.0
32.358
14.055
5.885
3.597
2.616
2.103
1.799
1.605
1.472
1.378
4.0
64.716
28.111
11.769
7.193
5.232
4.205
3.598
3.209
2.945
2.756
6.0
97.074
42.166
17.654
10.790
7.849
6.308
5.397
4.814
4.417
4.134
8.0
129.432
56.221
23.538
14.387
10.465
8.410
7.196
6.418
5.889
5.513
10.0
161.790
70.277
29.423
17.983
13.081
10.513
8.995
8.023
7.361
6.891
IEEE Moderately Inverse
0.5
3.220
1.902
1.216
0.973
0.844
0.763
0.706
0.663
0.630
0.603
1.0
6.439
3.803
2.432
1.946
1.688
1.526
1.412
1.327
1.260
1.207
2.0
12.878
7.606
4.864
3.892
3.377
3.051
2.823
2.653
2.521
2.414
4.0
25.756
15.213
9.729
7.783
6.753
6.102
5.647
5.307
5.041
4.827
6.0
38.634
22.819
14.593
11.675
10.130
9.153
8.470
7.960
7.562
7.241
8.0
51.512
30.426
19.458
15.567
13.507
12.204
11.294
10.614
10.083
9.654
10.0
64.390
38.032
24.322
19.458
16.883
15.255
14.117
13.267
12.604
12.068
IEC (BS) curve shape
K
E
t
r
IEC Curve A (BS142)
0.140
0.020
9.7
IEC Curve B (BS142)
13.500
1.000
43.2
IEC Curve C (BS142)
80.000
2.000
58.2
IEC Short Inverse
0.050
0.040
0.500
Multiplier
(TDM)
Current ( I / I
pickup
)
1.5
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
IEC Curve A
0.05
0.860
0.501
0.315
0.249
0.214
0.192
0.176
0.165
0.156
0.149
0.10
1.719
1.003
0.630
0.498
0.428
0.384
0.353
0.330
0.312
0.297
Multiplier
(TDM)
Current ( I / I
pickup
)
1.5
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
Summary of Contents for M60
Page 9: ...TABLE OF CONTENTS M60 MOTOR PROTECTION SYSTEM INSTRUCTION MANUAL ix INDEX ...
Page 10: ...x M60 MOTOR PROTECTION SYSTEM INSTRUCTION MANUAL TABLE OF CONTENTS ...
Page 552: ...5 344 M60 MOTOR PROTECTION SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 5 SETTINGS 5 ...
Page 660: ...iv M60 MOTOR PROTECTION SYSTEM INSTRUCTION MANUAL ABBREVIATIONS ...