Fuji Electric EW32EAG - Page 107

105
6
Short-circuit current calculation
6-1 Calculating short-circuit current
Table 6-3 Cable impedance examples (600V vinyl cable)
Cable gauge
Reactance per meter of cable (:) Resistance per meter of cable (:)
Insulated wire or cable inside
a steel tube or duct
Copper tube cable or vinyl
tube cable with no duct
Indoor cable with insulator
ø1.6mm 0.00020 0.00012 0.00031 0.0089
ø2mm 0.0056
ø3.2mm 0.0022
5.5mm
2
0.0033
8mm
2
0.0023
14mm
2
0.00015 0.00010 0.00026 0.0013
22mm
2
0.00082
30mm
2
0.00062
38mm
2
0.00048
50mm
2
0.00013 0.00009 0.00022 0.00037
60mm
2
0.00030
80mm
2
0.00023
100mm
2
0.00018
125mm
2
0.00014
150mm
2
0.00012
200mm
2
0.00009
250mm
2
0.00007
325mm
2
0.00005
.OTES s!DDREACTANCEONTHEPOWERSUPPLYSIDETOlNDTHEVALUEBECAUSE
reactance is 1.2 times higher at 60Hz.
s5SEORTHEACTUALCABLELENGTHTOCALCULATEREACTANCEAND
resistance when using two or three cables connected in parallel.
Table 6-4 Bus bar and bus duct impedance examples (50Hz) Data: Furukawa Electric Co., Ltd.
Material Rated current
(A)
Regular bus duct
Conductor dimensions
(mm)
Resistance
(:/m)
Reactance X
(:/m)
Impedance Z
(:/m)
Aluminum
(Al)
200
6 u 25 1.93 u 10
-4
1.25 u 10
-4
2.3 u 10
-4
400
6 u 50 0.97 u 10
-4
0.909 u 10
-4
1.33 u 10
-4
600
6 u 75 0.657 u 10
-4
0.72 u 10
-4
0.974 u 10
-4
800
6 u 125 0.404 u 10
-4
0.516 u 10
-4
0.655 u 10
-4
1000
6 u 150 0.343 u 10
-4
0.45 u 10
-4
0.566 u 10
-4
1200
6 u 100 u 2 0.249 u 10
-4
0.882 u 10
-4
0.916 u 10
-4
1500
6 u 125 u 2 0.201 u 10
-4
0.790 u 10
-4
0.815 u 10
-4
2000
6 u 200 u 2 0.133 u 10
-4
0.588 u 10
-4
0.603 u 10
-4
Copper
(Cu)
200
3 u 25 2.41 u 10
-4
1.312 u 10
-4
2.74 u 10
-4
400
6 u 40 0.751 u 10
-4
1.02 u 10
-4
1.267 u 10
-4
600
6 u 50 0.607 u 10
-4
0.91 u 10
-4
1.094 u 10
-4
800
6 u 75 0.412 u 10
-4
0.72 u 10
-4
0.830 u 10
-4
1000
6 u 100 0.315 u 10
-4
0.60 u 10
-4
0.678 u 10
-4
1200
6 u 125 0.261 u 10
-4
0.511 u 10
-4
0.573 u 10
-4
1500
6 u 150 0.221 u 10
-4
0.449 u 10
-4
0.500 u 10
-4
2000
6 u 125 u 2 0.129 u 10
-4
0.79 u 10
-4
0.800 u 10
-4