Copper Busbar Rating

 

Busbar Size
X Sectional area
Weight
Approx D.C
Resistance 20°C
Approx D.C rating (1)
Approx A.C rating
Moment of Inertia
Modulus of Section Z
Still Air (3)
Free Air (3)
Still Air
Free Air
Edge-wise
Flat
Edge-wise
Flat
mm
mm2
kg/m
mW/m
A
A
A
A
mm4
mm4
mm3
mm3
10 x 1.60
16.0
0.143
1077
105
115
105
115
133.3
3.413
26.66
4.266
12.5 x 1.60
20.0
0.179
862
125
135
125
135
260.4
4.266
41.66
5.333
16 x 1.60
25.6
0.229
673
155
170
155
170
546.1
5.461
68.26
6.826
20 x 1.60
32.0
0.286
538
185
205
185
205
1,066
6.826
106.6
8.533
25 x 1.60
40.0
0.357
431
225
250
225
250
2,083
8.533
166.6
10.67
30 x 1.60
48.0
0.429
359
265
290
265
290
3,600
10.24
240.0
12.80
10 x 2.00
20.0
0.179
862
115
130
115
130
166.6
6.666
33.32
6.666
12.5 x 2.00
25.0
0.223
689
140
155
140
155
325.5
8.333
52.08
8.333
16 x 2.00
32.0
0.286
538
175
190
175
190
682.6
10.66
85.33
10.66
20 x 2.00
40.0
0.357
431
210
230
210
230
1,333
13.33
133.3
13.33
25 x 2.00
50.0
0.446
344
255
280
255
280
2,604
16.66
208.3
16.66
30 x 2.00
60.0
0.536
287
295
330
295
330
4,500
20.00
300
20.00
40 x 2.00
80.0
0.714
215
380
420
380
420
10,660
26.66
533
26.66
10 x 2.50
25.0
0.223
689
130
145
130
145
208.3
13.02
41.66
10.42
12.5 x 2.50
31.25
02.279
557
160
175
160
175
406.9
16.27
65.60
13.02
16 x 2.50
40.0
0.357
431
195
215
195
215
853.3
20.83
106.70
16.66
20 x 2.50
50.0
0.446
344
235
260
235
260
1,666
26.04
166.6
20.83
25 x 2.50
62.5
0.558
275
285
315
285
315
3,255
32.55
260.4
26.04
30 x 2.50
75.0
0.670
229
330
370
330
370
5,625
39.06
375.0
31.25
40 x 2.50
100
0.893
172
425
475
425
475
13,330
52.08
666.5
41.66
50 x 2.50
125
1.115
137
520
575
520
575
26,040
65.10
1041
52.08
60 x 2.50
150
1.339
114
605
675
605
675
45,000
78.13
1500
62.50
10 x 2.75
31.5
0.281
547
150
170
150
170
262.5
26.05
5205
16.54
12.5 x 2.75
39.4
0.352
437
180
200
180
200
512.7
32.56
82.03
20.67
20 x 3.0
60.0
0.536
287
260
290
260
290
2,000
45.00
200.0
30.00
25 x 3.0
75
0.670
229
315
350
314
350
3,906
56.25
312.4
37.5
30 x 3.0
90
0.803
191
365
405
365
405
6,750
67.50
450.0
45.0
40 x 3.0
120
1.071
143
470
520
470
520
16,000
90.00
800.0
60.0
50 x 3.0
150
1.339
114
570
635
570
635
31,250
112.50
1,250
75.0
60 x 3.0
180
1.607
95.7
665
740
665
740
54,000
135.00
1,800
90.0
80 x 3.0
240
2.142
71.8
860
955
860
955
128 x 103
180.00
3,200
120.0
10 x 4.0
40
0.357
431
175
195
175
195
333.3
53.33
66.66
26.67
12.5 x 4.0
50
0.446
344
210
230
210
230
651.0
66.67
104.2
33.34
16 x 4.0
64
0.571
269
255
285
255
285
1,365
85.33
170.6
42.67
20 x 4.0
80
0.714
215
305
340
305
340
2,666
106.7
266.6
53.35
25 x 4.0
100
0.893
172
365
410
365
410
5,208
133.3
416.6
66.65
30 x 4.0
120
1,071
143
430
475
430
475
8,999
1600
599.6
80.00
40 x 4.0
160
1.428
107
545
610
540
605
21,330
213.3
1,066.5
106.7
50 x 4.0
200
1.785
86.2
665
740
660
735
41,660
266.7
1,666
133.4
60 x 4.0
240
2.142
71.8
775
860
770
855
72,000
320.0
2,400
160.0
80 x 4.0
320
2.856
53.8
995
1,120
980
1,105
170 x 103
426.7
4,268
213.4
100 x 4.0
400
3.571
43.1
1,210
1,365
1,185
1,340
333 x 103
533.3
6,666
266.7
10 x 5.0
50
0.446
344
200
225
200
225
416.7
104.2
83.34
41.68
12.5 x 5.0
62.5
0.558
275
240
265
240
265
813.4
130.2
130.1
52.08
16 x 5.0
80
0.714
215
290
325
290
325
1,707
166.7
213.4
66.68
20 x 5.0
100
0.893
172
345
385
345
385
3,333
208
333.3
83.20
25 x 5.0
125
1.116
137
415
465
415
465
6,560
260.4
520.8
104.2
30 x 5.0
150
1.339
114
485
540
480
540
11,250
312.5
750.0
125.0
40 x 5.0
200
1.785
86.2
615
685
610
680
26,670
416.7
1334
166.7
50 x 5.0
250
2.232
68.9
745
830
740
820
52,080
520.8
2,083
208.3
60 x 5.0
300
2.678
57.4
870
970
865
960
90,000
625.0
3,000
250.0
80 x 5.0
400
3571
431
1,120
1,260
1,110
1,250
213 x 103
833.3
5,333
333.3
100 x 5.0
500
4464
344
1,355
1,530
1,345
1,520
417 x 103
1,042
8,334
416.8
10 x 6.3
63
0.562
273
235
260
235
260
525
208.4
105.0
66.16
12.5 x 6.3
78.75
0.703
218
275
305
275
305
1,025
260.5
164.0
82.70
16 x 6.3
100.8
0.899
171
335
370
335
370
2,150
333.4
268.8
105.8
20 x 6.0
120
1.071
143
385
430
385
430
4,000
360.0
400.0
120.0
25 x 6.0
150
1.339
114
460
515
460
515
7,813
450.0
625.0
150.0
30 x 6.0
180
1.607
95.7
535
600
535
595
15,500
540.0
900.0
180.0
40 x 6.0
240
2.142
71.8
680
760
675
755
32,000
720.0
1,600
240.0
50 x 6.0
300
2.678
57.4
825
915
815
910
62,500
900.0
2,500
300.0
60 x 6.0
360
3.214
47.8
965
1,075
955
1,065
108 x 103
1,080
3,600
360.0
80 x 6.0
480
4.285
35.9
1,230
1,370
1,220
1,355
256 x 103
1,440
6,400
480.0
100 x 6.0
600
5.356
28.7
1,490
1,680
1,480
1,670
500 x 103
1,800
10,000
600.0
120 x 6.0
720
6.428
23.9
1,750
1,970
1,700
1,915
864 x 103
2,160
14,400
720.0
160 x 6.0
960
8.570
17.9
2,250
2,535
2,130
2,400
2.05 x 106
2,880
25,600
960.0
20 x 8.0
160
1.428
107
460
510
455
510
5,333
853.3
533.0
213.3
25 x 8.0
200
1.785
86.2
545
610
545
605
10,420
1,067
833.6
266.7
30 x 8.0
240
2.142
71.8
630
705
630
700
18,000
1,280
1,200
320.0
40 x 8.0
320
2.856
53.8
800
890
795
885
42,670
1,707
2,134
426.8
50 x 8.0
400
3.571
43.1
965
1,070
950
1,055
83,300
2,133
3,333
533.3
60 x 8.0
480
4.285
35.9
1,120
1,250
1,110
1,235
144 x 103
2,560
4,800
640.0
80 x 8.0
640
5.713
26.9
1,435
1,595
1,420
1,580
341 x 103
3,413
8,533
853.3
100 x 8.0
800
7.142
21.5
1,735
1,955
1,595
1,800
667 x 103
4,267
13,330
1067
120 x 8.0
960
8.570
17.9
2,032
2,290
1,760
1,985
1.15 x 106
5,120
19,200
1280
160 x 8.0
1280
11.43
13.4
2,610
2,935
2,230
2,510
2.73 x 106
6,827
34,140
1707
200 x 8.0
1600
14.27
10.8
3,170
3,570
2,760
3,110
5.33 x 106
8,533
53,330
2133
20 x 10
200
1.785
86.2
525
585
480
535
6,670
1,667
667
333.4
25 x 10
250
2.232
68.9
625
695
580
645
13,020
2,083
1,042
416.6
30 x 10
300
2.678
57.4
720
825
700
795
22,500
2,500
1,500
500.0
40 x 10
400
3.571
43.1
910
1,030
880
995
53,330
3,333
2,667
666.6
50 x 10
500
4.64
34.4
1,090
1,235
1,060
1,200
104 x 103
4,167
4,168
833.4
60 x 10
600
5.356
28.7
1,270
1,435
1,200
1,355
180 x 103
5,000
6,000
1,000
80 x 10
800
7.142
21.5
1,615
1,840
1,525
1,735
427 x 103
6,667
10,670
1,333
100 x 10
1,000
8.928
17.2
1,950
2,225
1,800
2,065
833 x 103
8,333
16,670
1,667
120 x 10
1,200
10.71
14.3
2,285
2,610
2,100
2,395
144 x 103
10,000
23,980
2,000
160 x 10
1,600
14.28
10.7
2,930
3,380
2,620
3,040
341 x 103
13,330
42,660
2,666
200 x 10
2,00
17.84
8.62
3,550
4,150
3,140
3,630
6.67 x 106
16,670
66,670
3,334
250 x 10
2,500
22.30
6.89
4,320
5,030
3,710
4,310
13.0 x 106
20,830
104 x 103
4,166
25 x 12
300
2.678
57.4
700
710
640
650
15,630
3,599
1,250
599.8
30 x 12
360
3.214
47.8
805
820
750
765
27,000
4,319
1,800
719.8
40 x 12
480
4.285
35.9
1,010
1,100
950
1,030
64,000
5,759
3,200
959.8
50 x 12
600
5.356
28.7
1,210
1,330
1,160
1,275
125 x 103
7,199
5,000
1,199
60 x 12
720
6.428
23.9
1,405
1,550
1,320
1,455
216 x 103
8,639
7,200
1,439
80 x 12
960
8.570
17.9
1,785
2,000
1,670
1,870
512 x 103
11,519
12,800
1,919
100 x 12
1,200
10.71
14.3
2,155
2,420
2,010
2,255
1.00 x 106
14,390
20,000
2,398
120 x 12
1,440
12.85
11.9
2,520
2,880
2,310
2,640
1.73 x 106
17,280
28,800
2,880
160 x 12
1,920
17.14
8.97
3,225
3,650
2,860
3,235
4.10 x 106
23,040
51,200
3,840
200 x 12
2,400
21.43
7.18
3,910
4,480
3,380
3,870
8.00 x 106
28,790
80,000
4,798
250 x 12
3,000
26.78
5.74
4,750
5,440
4,060
4,650
15.6 x 106
35,990
125 x 103
5,998
25 x 16
400
3.571
43.1
840
960
740
855
20,830
8,533
16.7 x 103
1,067
30 x 16
480
4.285
35.9
960
1,095
845
975
35,990
10,240
24.0 x 103
1,280
40 x 16
640
5.713
26.9
1,200
1,370
1,055
1,220
85,330
13,650
42.7 x 103
1,706
50 x 16
800
7.142
21.5
1,430
1,635
1,260
1,450
167 x 103
17,070
66.7 x 103
2,134
60 x 16
960
8.570
17.9
1,660
1,895
1,460
1,685
288 x 103
20,480
96.0 x 103
2,560
80 x 16
1,280
11.43
13.4
2,100
2,400
1,850
2,130
683 x 103
27,310
171 x 103
3,414
100 x 16
1,600
14.28
10.7
2,530
2,880
2,220
2,560
1.33 x 106
34,130
267 x 103
4,266
120 x 16
1,920
17.14
8.97
2,940
3,360
2,590
2,990
2.30 x 106
40,960
384 x 103
5,120
160 x 16
2,560
22.85
6.73
3,750
4,360
3,180
3,700
5.46 x 106
54,610
683 x 103
6,826
200 x 16
3,200
28.57
5.38
4,540
5,725
3,760
4,370
10.7 x 106
68,270
1.07 x 106
8,534
250 x 16
4,000
35.71
4.31
5,520
6,425
4,500
5,250
20.8 x 106
85,330
1.67 x 106
10,670
300 x 16
4,800
42.84
3.59
6,460
7,525
5,270
6,150
36.0 x 106
102 x 103
2.40 x 106
12,800
Notes:
1. Ratings apply for single bars on edge operating in a 40°C ambient temperature with 50°C temperature rise.
2. A.C. Ratings are for frequencies up to 60 Hz.
3. 'Free Air' Conditions assume some air movement other than convection currents, and may be applicable for outside installations. 'Still' and 'Free' Air Conditions both assume no enclosure.
4. Source data: www.cda.org.uk
BACK