Technical Information
Technical Information
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Copper Bus

Standard Pipe Sizes-Hard Drawn

Size Of Tube Inches Diameter Of Tube Inches

Wall Thickness Inch

 Area Of Copper

Weight For Foot Pounds

 *Resistance Per Foot Microohms** Moment Of Inertia I Inches4 Section Modulus S Inches3 Radius Of Gyration r Inches †Elastic Limit Per Tube Pounds ‡Breaking Strength Per Tube Pounds §Amperes 30° C. 1 Indoor Outdoor
Outside Inside Thousand Cir. Mils Square Inches
¼
3/8
½
¾
1
1 ¼
1 ½
2
2 ½
3
3½
4
4½
5
6		 .504
.675
.840
1.050
1.315
1.660
1.900
2.375
2.875
3.500
4.000
4.500
5.000
5.563
6.625 		0.375 .494 .625 .822 1.062 1.868 1.600 2.062 2.500 3.062 3.500 4.000 4.500 5.063 6.125 0.0825
.0905  .1075   .1140 .1265  .1460  .1500   .1565   .1875 .2190  .2500  .2500  .2500 .2500  .2500		 151.0 211.6
315.0
426.8 601.4 884.2
1,050.0 1,389.0
2,016.0
2,874.0
3,750.0
4,250.0
4,750.0
5,313.0
6,375.0

0.1186
.1662
.2474
.3352
.4723
.6944
.8247
1.091
1.583
2.257
2.945
3.338
3.731
4.173
5.007

 0.458
.642
.956
1.30
1.83
2.68
3.19
4.21
6.12
8.72
11.38
12.90
14.42
16.12
19.35

70.10
50.02
33.60
24.79
17.60
11.97
10.08
7.620
5.250
3.682
2.822
2.490
2.228
1.992
1.660

 .003203
.007267
.01695
.03726
.08434
.2008
.3180
.6744
1.456
3.051
5.200
7.563
10.55
14.76
25.47		 0.01186
.02153
.04035
.07096
.1288
.2420
.3347
.5679
.9991
1.743
2.600
3.361
4.220
5.305
7.690 		0.1644
.2091
.2618
.3334
.4226
.5378
.6210
.7863
.9525
1.163
1.329
1.505
1.682
1.881
2.256		 1,897.
2,659.
3,958.
5,364.
7,557.
11,110.
13,190.
17,450.
25,330.
36,120.
47,120.
53,410.
59,690.
66,770.
80,110. 		4 743.
6 647.
9 895.
13,410.
18,890.
27,780.
32,990.
43,630.
63,320.
90,290.
117,800.
133,500.
149,200.
166,900.
200,300.		 255
325
410
515
675
875 1
1,025 1
1,300 1
1,700 2
2,175 2
2,525 3
2,350 3
3,100 3
3,425 4
4,150 4

Notes:

1.  Courtesy Anaconda Wire and Cable Company;
2.  Tube dimension taken from A.S.T.M. Specification B-42-33,   Tabular values based on a Density of 0.322 pound per cubic inch.          
3.  * Conductivity of 98.0% I.A.C.S at 20°C. or 68°F.
4.  † Elastic Limit of 16.000 pounds per square inch,        
5.   ‡ Tensile strength of 40,000 pounds per square inch,
6.   ** 1 Microhm= 0.000 001 ohm
7.  § N.E.M . A. Electric Power Connector standards, Publication 37-47, September 1937, Sg 10-55 & Sg 10-56.
8.  Amperes capacity based on indoor mounting, not enclosed in separate regular.
9.  For temperature rises other than 30°.,  figure current capacity as follows: Rerating of tubes for changes in ambient, enclosure, or outdoor mounting must be based on the particular conditions to which each installation will be subjected. New current rating = ( New temperature rise/ 30 ½ X Current capacity for 30°C.rise.) Extra strong pipe size conductors have a 60 cycle capacity roughly 10% greater then      housing, 40°C_ ambient. Double extra heavy wall tubes with wall thickness over ½ inch have smaller current capacity than half-inch wall tubes. Ratings for the regular sizes are satisfactory for 60 cycles and d.c.