arc-flash analysis of utility power systems - Michigan Technological ...

Bus Voltage
(kV)
Table 4.1: 1 kV voltage level test system incident energy values
Incident Energy (cal/cm 2 )
Based on Bus
Voltage
Empirical Equation Lee Equation
0.5 109.89 1311.72 109.89
0.6 173.60 1112.42 173.60
0.7 274.65 966.29 274.65
0.8 433.71 852.72 433.71
0.9 683.28 761.94 683.28
1 1074.61 688.33 688.33
1.1 1688.36 628.00 628.00
1.2 2651.74 578.13 578.13
1.3 4167.63 536.78 536.78
1.4 6558.29 502.31 502.31
1.5 10345.38 473.69 473.69
Table 4.2: 15 kV voltage level test system incident energy values
Bus Voltage
(kV)
Incident Energy (cal/cm 2 )
Based on Bus
Voltage
Empirical Equation Lee Equation
14.0 0.94 21.50 0.94
14.1 0.94 21.81 0.94
14.2 0.95 22.12 0.95
14.3 0.96 22.43 0.96
14.4 0.96 22.75 0.96
14.5 0.97 23.07 0.97
14.6 0.98 23.38 0.98
14.7 0.99 23.70 0.99
14.8 0.99 24.03 0.99
14.9 1.00 24.36 1.00
15.0 1.01 24.68 1.01
15.1 1.01 25.01 25.01
15.2 1.02 25.34 25.34
15.3 1.03 25.68 25.68
15.4 1.04 26.02 26.02
15.5 1.04 26.35 26.35
15.6 1.05 26.69 26.69
15.7 1.06 27.04 27.04
15.8 1.06 27.38 27.38
15.9 1.07 27.73 27.73
16.0 1.08 28.08 28.08
This is especially concerning due to the fact the NESC does not specify at what
conditions the analysis is to be conducted; i.e. under light load or peak load conditions.
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