GE T60 User Manual

GE Multilin T60 Transformer Protection System 5-225
5 SETTINGS 5.6 GROUPED ELEMENTS
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 formulae for these curves are:
, (EQ 5.30)
where: T = operate time (in seconds), TDM = Multiplier setting, I = input current, I
pickup
= Pickup Current setting, K, E =
constants, t
r
= characteristic constant, and T
RESET
= reset time in seconds (assuming energy capacity is 100%
and
RESET is “Timed”)
Table 5–26: IEC (BS) INVERSE TIME CURVE CONSTANTS
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
Table 5–27: IEC CURVE TRIP TIMES (IN SECONDS)
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
0.20 3.439 2.006 1.260 0.996 0.856 0.767 0.706 0.659 0.623 0.594
0.40 6.878 4.012 2.521 1.992 1.712 1.535 1.411 1.319 1.247 1.188
0.60 10.317 6.017 3.781 2.988 2.568 2.302 2.117 1.978 1.870 1.782
0.80 13.755 8.023 5.042 3.984 3.424 3.070 2.822 2.637 2.493 2.376
1.00 17.194 10.029 6.302 4.980 4.280 3.837 3.528 3.297 3.116 2.971
IEC CURVE B
0.05 1.350 0.675 0.338 0.225 0.169 0.135 0.113 0.096 0.084 0.075
0.10 2.700 1.350 0.675 0.450 0.338 0.270 0.225 0.193 0.169 0.150
0.20 5.400 2.700 1.350 0.900 0.675 0.540 0.450 0.386 0.338 0.300
0.40 10.800 5.400 2.700 1.800 1.350 1.080 0.900 0.771 0.675 0.600
0.60 16.200 8.100 4.050 2.700 2.025 1.620 1.350 1.157 1.013 0.900
0.80 21.600 10.800 5.400 3.600 2.700 2.160 1.800 1.543 1.350 1.200
1.00 27.000 13.500 6.750 4.500 3.375 2.700 2.250 1.929 1.688 1.500
IEC CURVE C
0.05 3.200 1.333 0.500 0.267 0.167 0.114 0.083 0.063 0.050 0.040
0.10 6.400 2.667 1.000 0.533 0.333 0.229 0.167 0.127 0.100 0.081
0.20 12.800 5.333 2.000 1.067 0.667 0.457 0.333 0.254 0.200 0.162
0.40 25.600 10.667 4.000 2.133 1.333 0.914 0.667 0.508 0.400 0.323
0.60 38.400 16.000 6.000 3.200 2.000 1.371 1.000 0.762 0.600 0.485
0.80 51.200 21.333 8.000 4.267 2.667 1.829 1.333 1.016 0.800 0.646
1.00 64.000 26.667 10.000 5.333 3.333 2.286 1.667 1.270 1.000 0.808
IEC SHORT TIME
0.05 0.153 0.089 0.056 0.044 0.038 0.034 0.031 0.029 0.027 0.026
0.10 0.306 0.178 0.111 0.088 0.075 0.067 0.062 0.058 0.054 0.052
0.20 0.612 0.356 0.223 0.175 0.150 0.135 0.124 0.115 0.109 0.104
0.40 1.223 0.711 0.445 0.351 0.301 0.269 0.247 0.231 0.218 0.207
0.60 1.835 1.067 0.668 0.526 0.451 0.404 0.371 0.346 0.327 0.311
0.80 2.446 1.423 0.890 0.702 0.602 0.538 0.494 0.461 0.435 0.415
1.00 3.058 1.778 1.113 0.877 0.752 0.673 0.618 0.576 0.544 0.518
TTDM
K
II
pickup

E
1–
---------------------------------------
=
T
RESET
TDM
t
r
1 II
pickup

2
–
---------------------------------------
=

GE T60 Specifications

General

Brand	GE
Model	T60
Category	Relays
Language	English