Ampacities and Mechanical Properties of Rectangular Copper Busbars: Table 1. Ampacities of Copper No. 110

Ampacities of Copper No. 110 Busbars - Ampacities in the table below are for bus bars having an emissivity of 0.4. This was observed on samples exposed for 60 days in an industrial environment, and it is probably identical to that of bus bars in service.

Dimensions, In.AreaWeight Per Foot, LbDC Resistance at 20° C, Microhms Per Ft
Square In.Circular Mils, Thousands
1/16 x 1/2
1/16 x 3/4
1/16 x 1
1/16 x 1 1/2
1/16 x 2
0.0312
0.0469
0.0625
0.0938
0.125
39.7
59.7
79.6
119
159
0.121
0.181
0.241
0.362
0.483
264.0
175.0
132.0
87.7
65.8
1/8 x 1/2
1/8 x 3/4
1/8 x 1
1/8 x 1 1/2
1/8 x 2
1/8 x 2 1/2
1/8 x 3
1/8 x 3 1/2
1/8 x 4
0.0625
0.0938
0.125
0.188
0.250
0.312
0.375
0.438
0.500
79.6
119
159
239
318
397
477
558
636
0.241
0.362
0.483
0.726
0.966
1.21
1.45
1.69
1.93
132.0
87.7
65.8
43.8
32.9
26.4
21.9
18.8
16.5
3/16 x 1/2
3/16 x 3/4
3/16 x 1
3/16 x 1 1/2
3/16 x 2
3/16 x 2 1/2
3/16 x 3
3/16 x 3 1/2
3/16 x 4
0.0938
0.141
0.188
0.281
0.375
0.469
0.562
0.656
0.750
119
179
239
358
477
597
715
835
955
0.362
0.545
0.726
1.09
1.45
1.81
2.17
2.53
2.90
87.7
58.4
43.8
29.3
21.9
17.5
14.6
12.5
11.0
1/4 x 1/2
1/4 x 3/4
1/4 x 1
1/4 x 1 1/2
1/4 x 2
1/4 x 2 1/2
1/4 x 3
1/4 x 3 1/2
1/4 x 4
1/4 x 5
1/4 x 6
1/4 x 8
1/4 x 10
1/4 x 12
0.125
0.188
0.250
0.375
0.500
0.625
0.750
0.875
1.00
1.25
1.50
2.00
2.50
3.00
159
239
318
477
637
796
955
1,110
1,270
1,590
1,910
2,550
3,180
3,820
0.483
0.726
0.966
1.45
1.93
2.41
2.90
3.38
3.86
4.83
5.80
7.73
9.66
11.6
65.8
43.8
32.9
21.9
16.5
13.2
11.0
9.40
8.23
6.58
5.49
4.11
3.29
2.74
3/8 x 3/4
3/8 x 1
3/8 x 1 1/2
3/8 x 2
3/8 x 2 1/2
3/8 x 3
3/8 x 3 1/2
3/8 x 4
3/8 x 5
3/8 x 6
3/8 x 8
3/8 x 10
3/8 x 12
0.281
0.375
0.562
0.750
0.938
1.12
1.31
1.50
1.88
2.25
3.00
3.75
4.50
358
477
715
955
1,190
1,430
1,670
1,910
2,390
2,860
3,820
4,770
5,730
1.09
1.45
2.17
2.90
3.62
4.35
5.06
5.80
7.26
8.69
11.6
14.5
17.4
29.3
21.9
14.6
11.0
8.77
7.35
6.28
5.49
4.38
3.66
2.74
2.19
1.83
1/2 x 1
1/2 x 1 1/2
1/2 x 2
1/2 x 2 1/2
1/2 x 3
1/2 x 3 1/2
1/2 x 4
1/2 x 5
1/2 x 6
1/2 x 8
1/2 x 10
1/2 x 12
0.500
0.750
1.00
1.25
1.50
1.75
2.00
2.50
3.00
4.00
5.00
6.00
637
955
1,270
1,590
1,910
2,230
2,550
3,180
3,820
5,090
6,360
7,640
1.93
2.90
3.86
4.83
5.80
6.76
7.73
9.66
11.6
15.5
19.3
23.2
16.5
11.0
8.23
6.58
5.49
4.70
4.11
3.29
2.74
2.06
1.65
1.37
3/4 x 4
3/4 x 5
3/4 x 6
3/4 x 8
3/4 x 10
3/4 x 12
3.00
3.75
4.50
6.00
7.50
9.00
3,820
4,770
5,730
7,640
9,550
11,500
11.6
14.5
17.4
23.2
29.0
34.8
2.74
2.19
1.83
1.37
1.10
0.914
Dimensions, In.30 °C Rise50 °C Rise65 °C Rise
Skin Effect Ratio at 70° C60-Hz Ampacity,* AmpSkin Effect Ratio at 90° C60-Hz Ampacity, *AmpSkin Effect Ratio at 105° C60-Hz Ampacity, *Amp
1/16 x 1/2
1/16 x 3/4
1/16 x 1
1/16 x 1 1/2
1/16 x 2
1.00
1.00
1.00
1.00
1.01
103
145
187
270
345
1.00
1.00
1.00
1.00
1.01
136
193
250
355
460
1.00
1.00
1.00
1.00
1.01
157
225
285
410
530
1/8 x 1/2
1/8 x 3/4
1/8 x 1
1/8 x 1 1/2
1/8 x 2
1/8 x 2 1/2
1/8 x 3
1/8 x 3 1/2
1/8 x 4
1.00
1.00
1.01
1.01
1.02
1.02
1.03
1.04
1.04
153
215
270
385
495
600
710
810
910
1.00
1.00
1.01
1.01
1.02
1.02
1.03
1.03
1.04
205
285
360
510
660
800
940
1,100
1,200
1.00
1.00
1.01
1.01
1.02
1.02
1.03
1.03
1.04
235
325
415
590
760
920
1,100
1,250
1,400
3/16 x 1/2
3/16 x 3/4
3/16 x 1
3/16 x 1 1/2
3/16 x 2
3/16 x 2 1/2
3/16 x 3
3/16 x 3 1/2
3/16 x 4
1.00
1.01
1.01
1.02
1.03
1.04
1.05
1.07
1.09
195
270
340
480
610
740
870
990
1,100
1.00
1.01
1.01
1.02
1.03
1.04
1.05
1.06
1.08
260
360
455
630
810
980
1,150
1,300
1,450
1.00
1.01
1.01
1.02
1.03
1.03
1.04
1.06
1.07
300
415
520
730
940
1,150
1,350
1,500
1,700
1/4 x 1/2
1/4 x 3/4
1/4 x 1
1/4 x 1 1/2
1/4 x 2
1/4 x 2 1/2
1/4 x 3
1/4 x 3 1/2
1/4 x 4
1/4 x 5
1/4 x 6
1/4 x 8
1/4 x 10
1/4 x 12
1.01
1.01
1.02
1.03
1.04
1.06
1.08
1.10
1.12
1.16
1.18
1.23
1.27
1.31
240
320
400
560
710
850
990
1,150
1,250
1,500
1,750
2,250
2,700
3,150
1.01
1.01
1.02
1.03
1.04
1.06
1.08
1.09
1.11
1.15
1.17
1.22
1.26
1.30
315
425
530
740
940
1,150
1,300
1,500
1,700
2,000
2,350
3,000
3,600
4,200
1.01
1.01
1.02
1.03
1.04
1.06
1.07
1.09
1.10
1.14
1.17
1.21
1.25
1.28
360
490
620
860
1,100
1,300
1,550
1,750
1,950
2,350
2,700
3,450
4,200
4,900
3/8 x 3/4
3/8 x 1
3/8 x 1 1/2
3/8 x 2
3/8 x 2 1/2
3/8 x 3
3/8 x 3 1/2
3/8 x 4
3/8 x 5
3/8 x 6
3/8 x 8
3/8 x 10
3/8 x 12
1.02
1.03
1.05
1.08
1.12
1.15
1.18
1.20
1.24
1.27
1.33
1.38
1.42
415
510
710
880
1,050
1,200
1,350
1,500
1,800
2,100
2,650
3,200
3,700
1.02
1.03
1.04
1.08
1.10
1.14
1.16
1.19
1.23
1.26
1.31
1.36
1.40
550
680
940
1,150
1,400
1,600
1,800
2,000
2,400
2,800
3,550
4,300
5,000
1.02
1.03
1.04
1.07
1.09
1.13
1.15
1.18
1.22
1.24
1.30
1.35
1.38
630
790
1,100
1,350
1,600
1,850
2,100
2,350
2,800
3,250
4,100
4,900
5,800
1/2 x 1
1/2 x 1 1/2
1/2 x 2
1/2 x 2 1/2
1/2 x 3
1/2 x 3 1/2
1/2 x 4
1/2 x 5
1/2 x 6
1/2 x 8
1/2 x 10
1/2 x 12
1.04
1.08
1.12
1.16
1.20
1.24
1.26
1.32
1.36
1.42
1.47
1.52
620
830
1,000
1,200
1,400
1,550
1,700
2,050
2,400
3,000
3,600
4,200
1.04
1.08
1.11
1.15
1.19
1.22
1.25
1.30
1.34
1.40
1.45
1.51
820
1,100
1,350
1,600
1,850
2,100
2,300
2,750
3,150
4,000
4,800
5,600
1.04
1.07
1.10
1.14
1.18
1.21
1.24
1.29
1.33
1.39
1.44
1.50
940
1,250
1,550
1,850
2,150
2,400
2,650
3,150
3,650
4,600
5,500
6,400
3/4 x 4
3/4 x 5
3/4 x 6
3/4 x 8
3/4 x 10
3/4 x 12
1.42
1.48
1.52
1.60
1.67
1.72
2,050
2,400
2,800
3,500
4,200
4,900
1.40
1.46
1.50
1.58
1.64
1.69
2,750
3,250
3,750
4,700
5,600
6,500
1.38
1.44
1.48
1.56
1.62
1.67
3,150
3,750
4,300
5,400
6,500
7,500
* Applicable to typical in-service conditions (indoors, 40°C ambient temperature), horizontal run on edge, and free from external magnetic influences.