IDMT Relay Setting Calculation

Relay-1 Relay-2

Feeder Type :

Protection Type :

System Voltage(KV) : 33 33

System Load(KVA) : 50000 50000

Relay Code :

Relay No :

CT.Pri (A) : 500 500

CT.Sec (A) : 5 5

Primary Fault Current (Amp) : 4500 4500

Grading of Relay (Sec) : 0.3 0.3

System Current (Amp) : 875 875

1.75 1.75

1.75 1.75

Time Setting (TMS) Sec : 0.1 0.5

Curve Selection : Normal Inverse (NI) Normal Inverse (NI)

CT Ratio (Amp) : 100 100

Relay Pick Up Current (Amp) : 8.75 8.75

PSM : 5.143 5.143

Relay OperatingTime (Sec) : 4.205 4.205

0.420 2.102

0.720 2.402

Enter Data in White Background Cells

Jignesh.Parmar, www.electricalnotes.wordpress.com,jiguparmar@yahoo.com

Required Pick Up Setting of Relay: ( X In)

Actual Pick Up Setting of Relay: ( X In)

Actual Operating Time of Relay (Sec) :

Operating Time of Previous Up steam Relay (Sec):

IDMT Relay Setting Calculation IDMT Relay Curve

Relay-3 Relay-4 Relay-5

33 33 33

50000 50000 50000

500 500 100

5 5 5

4500 4500 4500

0.3 0.3 0.3

875 875 875

1.75 1.75 8.75

1.75 1.75 1.75

0.8 0.9 0.1

Normal Inverse (NI) Normal Inverse (NI) Normal Inverse (NI)

100 100 20

8.75 8.75 8.75

5.143 5.143 25.714

4.205 4.205 2.087

3.364 3.784 0.209

3.664 4.084 0.509

Jignesh.Parmar, www.electricalnotes.wordpress.com,jiguparmar@yahoo.com

0 2000 4000 6000 8000 10000 120000.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600

1.800

Relay-1Relay-2Relay-3Relay-4Relay-5

Primary Current (Amp)

Rela

y Pi

ck u

p (S

ec)

IDMT Relay Curve

0 2000 4000 6000 8000 10000 120000.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600

1.800

Relay-1Relay-2Relay-3Relay-4Relay-5

Primary Current (Amp)

Rela

y Pi

ck u

p (S

ec)

Normal Inverse (NI)

Very Inverse (VI)

Exteremely Inverse (EI)

Long Inverse

2

Relay-1 0.100

0.5 250 50 0.172 0.5

1 500 100 0.145 1

1.5 750 150 0.133 1.5

2.5 1250 250 0.120 2.5

3 1500 300 0.116 3

3.5 1750 350 0.113 3.5

4 2000 400 0.110 4

4.5 2250 450 0.108 4.55.5 2750 550 0.104 5.56 3000 600 0.103 6

6.5 3250 650 0.101 6.5

7 3500 700 0.100 7

7.5 3750 750 0.099 7.5

8 4000 800 0.098 8

8.5 4250 850 0.097 8.5

9 4500 900 0.096 9

9.5 4750 950 0.095 9.510 5000 1000 0.094 1010.5 5250 1050 0.094 10.511 5500 1100 0.093 1111.5 5750 1150 0.092 11.512 6000 1200 0.092 1212.5 6250 1250 0.091 12.513 6500 1300 0.091 1313.5 6750 1350 0.090 13.514 7000 1400 0.090 1414.5 7250 1450 0.089 14.5

15 7500 1500 0.089 1515.5 7750 1550 0.088 15.516 8000 1600 0.088 1616.5 8250 1650 0.088 16.517 8500 1700 0.087 1717.5 8750 1750 0.087 17.518 9000 1800 0.087 1818.5 9250 1850 0.086 18.519 9500 1900 0.086 1919.5 9750 1950 0.086 19.520 10000 2000 0.085 20

Relay-1 Relay-2250 0.172 250 0.860 250500 0.145 500 0.726 500750 0.133 750 0.664 7501250 0.120 1250 0.600 12501500 0.116 1500 0.579 15001750 0.113 1750 0.563 17502000 0.110 2000 0.550 20002250 0.108 2250 0.539 22502750 0.104 2750 0.520 27503000 0.103 3000 0.513 30003250 0.101 3250 0.506 32503500 0.100 3500 0.500 35003750 0.099 3750 0.494 37504000 0.098 4000 0.489 40004250 0.097 4250 0.485 42504500 0.096 4500 0.480 45004750 0.095 4750 0.476 47505000 0.094 5000 0.472 50005250 0.094 5250 0.469 52505500 0.093 5500 0.466 55005750 0.092 5750 0.462 57506000 0.092 6000 0.459 60006250 0.091 6250 0.457 62506500 0.091 6500 0.454 65006750 0.090 6750 0.451 67507000 0.090 7000 0.449 70007250 0.089 7250 0.447 72507500 0.089 7500 0.444 75007750 0.088 7750 0.442 77508000 0.088 8000 0.440 80008250 0.088 8250 0.438 82508500 0.087 8500 0.436 8500

8750 0.087 8750 0.435 87509000 0.087 9000 0.433 90009250 0.086 9250 0.431 92509500 0.086 9500 0.429 95009750 0.086 9750 0.428 975010000 0.085 10000 0.426 10000

Relay-2 0.500 Relay-3 0.800 Relay-4

250 50 0.860 0.5 250 50 1.376 0.5 250 50

500 100 0.726 1 500 100 1.161 1 500 100

750 150 0.664 1.5 750 150 1.063 1.5 750 150

1250 250 0.600 2.5 1250 250 0.959 2.5 1250 250

1500 300 0.579 3 1500 300 0.927 3 1500 300

1750 350 0.563 3.5 1750 350 0.901 3.5 1750 350

2000 400 0.550 4 2000 400 0.880 4 2000 400

2250 450 0.539 4.5 2250 450 0.862 4.5 2250 4502750 550 0.520 5.5 2750 550 0.833 5.5 2750 5503000 600 0.513 6 3000 600 0.821 6 3000 600

3250 650 0.506 6.5 3250 650 0.810 6.5 3250 650

3500 700 0.500 7 3500 700 0.800 7 3500 700

3750 750 0.494 7.5 3750 750 0.791 7.5 3750 750

4000 800 0.489 8 4000 800 0.783 8 4000 800

4250 850 0.485 8.5 4250 850 0.775 8.5 4250 850

4500 900 0.480 9 4500 900 0.769 9 4500 900

4750 950 0.476 9.5 4750 950 0.762 9.5 4750 9505000 1000 0.472 10 5000 1000 0.756 10 5000 10005250 1050 0.469 10.5 5250 1050 0.750 10.5 5250 10505500 1100 0.466 11 5500 1100 0.745 11 5500 11005750 1150 0.462 11.5 5750 1150 0.740 11.5 5750 11506000 1200 0.459 12 6000 1200 0.735 12 6000 12006250 1250 0.457 12.5 6250 1250 0.731 12.5 6250 12506500 1300 0.454 13 6500 1300 0.726 13 6500 13006750 1350 0.451 13.5 6750 1350 0.722 13.5 6750 13507000 1400 0.449 14 7000 1400 0.718 14 7000 14007250 1450 0.447 14.5 7250 1450 0.715 14.5 7250 1450

7500 1500 0.444 15 7500 1500 0.711 15 7500 15007750 1550 0.442 15.5 7750 1550 0.708 15.5 7750 15508000 1600 0.440 16 8000 1600 0.704 16 8000 16008250 1650 0.438 16.5 8250 1650 0.701 16.5 8250 16508500 1700 0.436 17 8500 1700 0.698 17 8500 17008750 1750 0.435 17.5 8750 1750 0.695 17.5 8750 17509000 1800 0.433 18 9000 1800 0.693 18 9000 18009250 1850 0.431 18.5 9250 1850 0.690 18.5 9250 18509500 1900 0.429 19 9500 1900 0.687 19 9500 19009750 1950 0.428 19.5 9750 1950 0.685 19.5 9750 195010000 2000 0.426 20 10000 2000 0.682 20 10000 2000

Relay-3 Relay-4 Relay-51.376 250 1.548 50 0.2971.161 500 1.306 100 0.2271.063 750 1.195 150 0.1990.959 1250 1.079 250 0.1720.927 1500 1.043 300 0.1640.901 1750 1.014 350 0.1580.880 2000 0.990 400 0.1530.862 2250 0.970 450 0.1490.833 2750 0.937 550 0.1420.821 3000 0.923 600 0.1390.810 3250 0.911 650 0.1370.800 3500 0.900 700 0.1350.791 3750 0.890 750 0.1330.783 4000 0.881 800 0.1310.775 4250 0.872 850 0.1290.769 4500 0.865 900 0.1280.762 4750 0.857 950 0.1270.756 5000 0.850 1000 0.1250.750 5250 0.844 1050 0.1240.745 5500 0.838 1100 0.1230.740 5750 0.832 1150 0.1220.735 6000 0.827 1200 0.1210.731 6250 0.822 1250 0.1200.726 6500 0.817 1300 0.1190.722 6750 0.813 1350 0.1180.718 7000 0.808 1400 0.1170.715 7250 0.804 1450 0.1170.711 7500 0.800 1500 0.1160.708 7750 0.796 1550 0.1150.704 8000 0.792 1600 0.1140.701 8250 0.789 1650 0.1140.698 8500 0.786 1700 0.113

0.695 8750 0.782 1750 0.1130.693 9000 0.779 1800 0.1120.690 9250 0.776 1850 0.1120.687 9500 0.773 1900 0.1110.685 9750 0.770 1950 0.1100.682 10000 0.767 2000 0.110

0.900 Relay-5 0.100

1.548 0.5 50 10 0.297

1.306 1 100 20 0.227

1.195 1.5 150 30 0.199

1.079 2.5 250 50 0.172

1.043 3 300 60 0.164

1.014 3.5 350 70 0.158

0.990 4 400 80 0.153

0.970 4.5 450 90 0.1490.937 5.5 550 110 0.1420.923 6 600 120 0.139

0.911 6.5 650 130 0.137

0.900 7 700 140 0.135

0.890 7.5 750 150 0.133

0.881 8 800 160 0.131

0.872 8.5 850 170 0.129

0.865 9 900 180 0.128

0.857 9.5 950 190 0.1270.850 10 1000 200 0.1250.844 10.5 1050 210 0.1240.838 11 1100 220 0.1230.832 11.5 1150 230 0.1220.827 12 1200 240 0.1210.822 12.5 1250 250 0.1200.817 13 1300 260 0.1190.813 13.5 1350 270 0.1180.808 14 1400 280 0.1170.804 14.5 1450 290 0.117

0.800 15 1500 300 0.1160.796 15.5 1550 310 0.1150.792 16 1600 320 0.1140.789 16.5 1650 330 0.1140.786 17 1700 340 0.1130.782 17.5 1750 350 0.1130.779 18 1800 360 0.1120.776 18.5 1850 370 0.1120.773 19 1900 380 0.1110.770 19.5 1950 390 0.1100.767 20 2000 400 0.110