Appendix A
Impedance Tables for Lines, Transformers, and Underground Cables
Table A.1
Characteristics of Copper Conductors, Hard-Drawn, 97.3% Conductivity
Size of Conductor Circular Mils |
AWC or B & S |
Number of Strands |
Diameter of Individual Strands (in.) |
Outside Diameter (in.) |
Breaking Strength (lb) |
Weight (Ib/mi) |
Approx. Current Carrying Capacitya (amps) |
Geometric Mean Radius at 60 Cycles (ft) |
ra Resistance (Ω/Conductor/mi) |
Xa Inductive Reactance (Ω/Conductor/mi) at 1 ft Spacing |
X'a Shunt Capacitive Reactance (MΩ · mi/Conductor) at 1 ft Spacing) |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
25°C (77°F) |
50°C (122°F) |
|||||||||||||||||||||
DC |
25 Cycles |
50 Cycles |
60 Cycles |
DC |
25 Cycles |
50 Cycles |
60 Cycles |
25 Cycles |
50 Cycles |
60 Cycles |
25 Cycles |
50 Cycles |
60 Cycles |
|||||||||
1,000,000 |
— |
37 |
0.1644 |
1.151 |
43,830 ... | |||||||||||||||||
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