GE Multilin B30 Bus Differential System 5-1295 SETTINGS 5.6 GROUPED ELEMENTS5IEC CURVESFor European applications, the relay offers three standard curves defined in IEC 255-4 and British standard BS142. Theseare defined as IEC Curve A, IEC Curve B, and IEC Curve C. The formulae for these curves are:, (EQ 5.5)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 5–14: IEC (BS) INVERSE TIME CURVE CONSTANTSIEC (BS) CURVE SHAPE K E TRIEC Curve A (BS142) 0.140 0.020 9.7IEC Curve B (BS142) 13.500 1.000 43.2IEC Curve C (BS142) 80.000 2.000 58.2IEC Short Inverse 0.050 0.040 0.500Table 5–15: 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 10.0IEC CURVE A0.05 0.860 0.501 0.315 0.249 0.214 0.192 0.176 0.165 0.156 0.1490.10 1.719 1.003 0.630 0.498 0.428 0.384 0.353 0.330 0.312 0.2970.20 3.439 2.006 1.260 0.996 0.856 0.767 0.706 0.659 0.623 0.5940.40 6.878 4.012 2.521 1.992 1.712 1.535 1.411 1.319 1.247 1.1880.60 10.317 6.017 3.781 2.988 2.568 2.302 2.117 1.978 1.870 1.7820.80 13.755 8.023 5.042 3.984 3.424 3.070 2.822 2.637 2.493 2.3761.00 17.194 10.029 6.302 4.980 4.280 3.837 3.528 3.297 3.116 2.971IEC CURVE B0.05 1.350 0.675 0.338 0.225 0.169 0.135 0.113 0.096 0.084 0.0750.10 2.700 1.350 0.675 0.450 0.338 0.270 0.225 0.193 0.169 0.1500.20 5.400 2.700 1.350 0.900 0.675 0.540 0.450 0.386 0.338 0.3000.40 10.800 5.400 2.700 1.800 1.350 1.080 0.900 0.771 0.675 0.6000.60 16.200 8.100 4.050 2.700 2.025 1.620 1.350 1.157 1.013 0.9000.80 21.600 10.800 5.400 3.600 2.700 2.160 1.800 1.543 1.350 1.2001.00 27.000 13.500 6.750 4.500 3.375 2.700 2.250 1.929 1.688 1.500IEC CURVE C0.05 3.200 1.333 0.500 0.267 0.167 0.114 0.083 0.063 0.050 0.0400.10 6.400 2.667 1.000 0.533 0.333 0.229 0.167 0.127 0.100 0.0810.20 12.800 5.333 2.000 1.067 0.667 0.457 0.333 0.254 0.200 0.1620.40 25.600 10.667 4.000 2.133 1.333 0.914 0.667 0.508 0.400 0.3230.60 38.400 16.000 6.000 3.200 2.000 1.371 1.000 0.762 0.600 0.4850.80 51.200 21.333 8.000 4.267 2.667 1.829 1.333 1.016 0.800 0.6461.00 64.000 26.667 10.000 5.333 3.333 2.286 1.667 1.270 1.000 0.808IEC SHORT TIME0.05 0.153 0.089 0.056 0.044 0.038 0.034 0.031 0.029 0.027 0.0260.10 0.306 0.178 0.111 0.088 0.075 0.067 0.062 0.058 0.054 0.0520.20 0.612 0.356 0.223 0.175 0.150 0.135 0.124 0.115 0.109 0.1040.40 1.223 0.711 0.445 0.351 0.301 0.269 0.247 0.231 0.218 0.2070.60 1.835 1.067 0.668 0.526 0.451 0.404 0.371 0.346 0.327 0.3110.80 2.446 1.423 0.890 0.702 0.602 0.538 0.494 0.461 0.435 0.4151.00 3.058 1.778 1.113 0.877 0.752 0.673 0.618 0.576 0.544 0.518T TDMKI I pickup⁄( )E 1–---------------------------------------×= T RESET TDMt r1 I I pickup⁄( )2–---------------------------------------×=
