42 Electrical design and installation
Manual Power Quality Filter PQFS
Table 20: Allowed cable current for different cable sections noting the skin effect and typical
cable manufacturer data – Network frequency 60Hz
Copper
Aluminum
Cross section
Nr of
parallel
cables
Derating
due to
paralleling
Rated
current
[Arms]
Reduction
factor
Allowed
current
[Arms]
Rated
current
[Arms]
Reduction
factor
Allowed
current
[Arms]
[mm²]
[AWG]
16
6
1
1
100
0.996
99
75
1
75
25
4
1
1
130
0.99
128
100
1
100
35
2
1
1
160
0.981
157
120
0.99
119
50
1-1/0
1
1
190
0.965
183
145
0.98
143
70
2/0
1
1
230
0.941
216
180
0.97
175
95
3/0
1
1
285
0.911
260
220
0.95
210
120
4/0
1
1
325
0.88
286
250
0.93
233
150
300MCM
1
1
365
0.85
310
285
0.91
260
185
350MCM
1
1
415
0.817
339
325
0.89
288
240
500MCM
1
1
495
0.775
383
385
0.85
326
300
600MCM
1
1
550
0.738
406
425
0.81
346
16
6
2
0.8
160
0.996
159
120
1
120
25
4
2
0.8
208
0.99
205
160
1
160
35
2
2
0.8
256
0.981
250
192
0.99
190
50
1-1/0
2
0.8
304
0.965
293
232
0.98
228
70
2/0
2
0.8
368
0.941
346
288
0.97
280
95
3/0
2
0.8
456
0.911
415
352
0.95
336
120
4/0
2
0.8
520
0.88
457
400
0.93
374
150
300MCM
2
0.8
584
0.85
496
456
0.91
416
185
350MCM
2
0.8
664
0.817
542
520
0.89
460
240
500MCM
2
0.8
792
0.775
613
616
0.85
522
300
600MCM
2
0.8
880
0.738
649
680
0.81
553
Remark: The highlighted values in
refer to cable sizes that correspond to typical
filter ratings. Note that in 4-wire systems, the neutral may have to carry up to 3 times
the line current rating of the filter.
6.7
Selection of the power cable protection/filter input protection
scheme
Once the power cables have been selected, a suitable cable and equipment protection
has to be selected. The protection only needs to protect the phases and not the neutral.
It is recommended to use fuses of type gG/gL with the RMS current ratings given in
