Chart of Maximum Short Circuit Force in Buses.


The following table can be used to determine the force between two busses during a short circuit condition. Find the short circuit current in the first column and then find the distance between conductors at the top of the chart. The distance is given in inches. The short circuit current is given in amps. The resultant force in the chart is given in pounds per foot. This chart is base on the formula:
FORCE = (43.2 * SSA * SSA * 1x10-7)/D
where:
SSA = short circuit amps
D = distance between centers of conductors.



Chart of Maximum Short Circuit Force in Buses

.

SSA12" 15" 18" 21" 24" 27" 30" 33" 36" 40" 50" 60" 70" 80"
2000 1.4 1.2 1.0 0.8 0.7 0.6 0.6 0.5 0.5 0.4 0.3 0.3 0.2 0.2
2500 2.3 1.8 1.5 1.3 1.1 1.0 0.9 0.8 0.8 0.7 0.5 0.5 0.4 0.3
3000 3.2 2.6 2.2 1.9 1.6 1.4 1.3 1.2 1.1 1.0 0.8 0.6 0.6 0.5
4000 5.8 4.6 3.8 3.3 2.9 2.6 2.3 2.1 1.9 1.7 1.4 1.2 1.0 0.9
5000 9.0 7.2 6.0 5.1 4.5 4.0 3.6 3.3 3.0 2.7 2.2 1.8 1.5 1.4
6000 13.0 10.4 8.6 7.4 6.5 5.8 5.2 4.7 4.3 3.9 3.1 2.6 2.2 1.9
7000 17.6 14.1 11.8 10.1 8.8 7.8 7.1 6.4 5.9 5.3 4.2 3.5 3.0 2.6
8000 23.0 18.4 15.4 13.2 11.5 10.2 9.2 8.4 7.7 6.9 5.5 4.6 3.9 3.5
9000 29.2 23.3 19.4 16.7 14.6 13.0 11.7 10.6 9.7 8.7 7.0 5.8 5.0 4.4
10000 36.0 28.8 24.0 20.6 18.0 16.0 14.4 13.1 12.0 10.8 8.6 7.2 6.2 5.4
12000 51.8 41.5 34.6 29.6 25.9 23.0 20.7 18.9 17.3 15.6 12.4 10.4 8.9 7.8
15000 81.0 64.8 54.0 46.3 40.5 36.0 32.4 29.5 27.0 24.3 19.4 16.2 13.9 12.2
20000 144.0 115.2 96.0 82.3 72.0 64.0 57.6 52.4 48.0 43.2 34.6 28.8 24.7 21.6
25000 225.0 180.0 150.0 128.6 112.5 100.0 90.0 81.8 75.0 67.5 54.0 45.0 38.6 33.8
30000 324.0 259.2 216.0 185.1 162.0 144.0 129.6 117.8 108.0 97.2 77.8 64.8 55.5 48.6
35000 441.0 352.8 294.0 252.0 220.5 196.0 176.4 160.4 147.0 132.3 105.8 88.2 75.6 66.2
40000 576.0 460.8 384.0 329.1 288.0 256.0 230.4 209.5 192.0 172.8 138.2 115.2 98.7 86.4
45000 729.0 583.2 486.0 416.6 364.5 324.0 291.6 265.1 243.0 218.7 175.0 145.8 125.0 109.4
50000 900.0 720.0 600.0 514.3 450.0 400.0 360.0 327.3 300.0 270.0 216.0 180.0 154.3 135.0
60000 1296.0 1036.8 864.0 740.6 648.0 576.0 518.4 471.3 432.0 388.8 311.0 259.2 222.2 194.4
70000 1764.0 1411.2 1176.0 1008.0 882.0 784.0 705.6 641.5 588.0 529.2 423.4 352.8 302.4 264.6
80000 2304.0 1843.2 1536.0 1316.6 1152.0 1024.0 921.6 837.8 768.0 691.2 553.0 460.8 395.0 345.6
90000 2916.0 2332.8 1944.0 1666.3 1458.0 1296.0 1166.4 1060.4 972.0 874.8 699.8 583.2 499.9 437.4
100000 3600.0 2880.0 2400.0 2057.1 1800.0 1600.0 1440.0 1309.1 1200.0 1080.0 864.0 720.0 617.1 540.0


Notes:
#1. These values are for educational purposes only.
Due to the wide range of circuit applications, the author assumes no responsibility for the application of these values.


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