PDHonline Course E275 (3 PDH)
AWG and Circular Mils
Instructor: David A. Snyder, PE
2012
PDH Online | PDH Center
5272 Meadow Estates Drive
Fairfax, VA 22030-6658
Phone & Fax: 703-988-0088
www.PDHonline.org
www.PDHcenter.com
An Approved Continuing Education Provider
TABLE 1 - Bus Bar Choices
Thickness
(in.)
0.375
0.375
0.375
0.375
0.375
0.375
0.375
0.375
0.375
0.375
0.375
0.375
0.375
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
Printed 1/21/2009 1:30 PM
Width (in.)
Area
2
(in )
Calc'd Area
(Circular
Mils)
Nominal
Area
(KCMIL)
0.75
1
1.5
2
2.5
3
3.5
4
5
6
8
10
12
1
1.5
2
2.5
3
3.5
4
5
6
8
10
12
2
2.5
3
4
5
6
8
10
12
0.281
0.375
0.563
0.750
0.938
1.125
1.313
1.500
1.875
2.250
3.000
3.750
4.500
0.500
0.750
1.000
1.250
1.500
1.750
2.000
2.500
3.000
4.000
5.000
6.000
1.500
1.875
2.250
3.000
3.750
4.500
6.000
7.500
9.000
358,280
477,707
716,561
955,414
1,194,268
1,433,121
1,671,975
1,910,828
2,388,535
2,866,242
3,821,656
4,777,070
5,732,484
636,943
955,414
1,273,885
1,592,357
1,910,828
2,229,299
2,547,771
3,184,713
3,821,656
5,095,541
6,369,427
7,643,312
1,910,828
2,388,535
2,866,242
3,821,656
4,777,070
5,732,484
7,643,312
9,554,140
11,464,968
358
477
715
955
1,190
1,430
1,670
1,910
2,390
2,860
3,820
4,770
5,730
637
955
1,270
1,590
1,910
2,230
2,550
3,180
3,820
5,090
6,360
7,640
1,910
2,390
2,860
3,820
4,770
5,730
7,640
9,550
11,500
Tables.xls : Table 1
Page 1 of 10
TABLE 2 - Wire Gage, Mils, Circular Mils, and Strand Quantities
AWG
(American
Wire Gage)
1,000 KCMIL
900 KCMIL
800 KCMIL
750 KCMIL
700 KCMIL
600 KCMIL
500 KCMIL
400 KCMIL
350 KCMIL
300 KCMIL
250 KCMIL
4/0 or 0000
3/0 or 000
2/0 or 00
1/0 or 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Solid Wire
Diameter
(Mils)
1,000.0
948.7
894.4
866.0
836.7
774.6
707.1
632.5
591.6
547.7
500.0
460.0
409.6
364.8
324.9
289.3
257.6
229.4
204.3
181.9
162.0
144.3
128.5
114.4
101.9
90.7
80.8
72.0
64.1
57.1
50.8
45.3
40.3
35.9
32.0
28.5
25.3
22.6
20.1
17.9
15.9
14.2
12.6
11.3
10.0
8.9
8.0
7.1
6.3
5.6
5.0
4.5
4.0
3.5
3.1
Printed 1/21/2009 1:30 PM
Calculated
Area (C.M.)
1,000,000.0
900,031.7
799,951.4
749,956.0
700,066.9
600,005.2
499,990.4
400,056.3
349,990.6
299,975.3
250,000.0
211,600.0
167,772.2
133,079.0
105,560.0
83,694.5
66,357.8
52,624.4
41,738.5
33,087.6
26,244.0
20,822.5
16,512.3
13,087.4
10,383.6
8,226.5
6,528.6
5,184.0
4,108.8
3,260.4
2,580.6
2,052.1
1,624.1
1,288.8
1,024.0
812.3
640.1
510.8
404.0
320.4
252.8
201.6
158.8
127.7
100.0
79.2
64.0
50.4
39.7
31.4
25.0
20.3
16.0
12.3
9.6
Nominal Area Strand
NEC Table 8 Qty (May Diam./ Strand Area/ Strand
(C.M.)
Vary)
(Mils)
(C.M.)
1,000,000
61
128.0
16,384.0
900,000
61
121.5
14,762.3
800,000
61
114.5
13,110.3
750,000
61
110.9
12,298.8
700,000
61
107.1
11,470.4
600,000
61
99.2
9,840.6
500,000
37
116.2
13,502.4
400,000
37
104.0
10,816.0
350,000
37
97.3
9,467.3
300,000
37
90.0
8,100.0
250,000
37
82.2
6,756.8
211,600
19
105.5
11,130.3
167,800
19
94.0
8,836.0
133,100
19
83.7
7,005.7
105,600
19
74.5
5,550.3
83,690
19
66.4
4,409.0
66,360
7
97.4
9,486.8
52,620
7
86.7
7,516.9
41,740
7
77.2
5,959.8
N.A.
7
68.8
4,733.4
26,240
7
61.2
3,745.4
N.A.
7
54.5
2,970.3
16,510
7
48.6
2,362.0
N.A.
7
43.2
1,866.2
10,380
7
38.5
1,482.3
N.A.
7
34.3
1,175.4
6,530
7
30.5
930.3
N.A.
7
27.2
737.7
4,110
7
24.2
585.6
N.A.
7
21.6
464.4
2,580
7
19.2
368.6
N.A.
7
17.1
292.3
1,620
7
15.2
231.0
N.A.
7
13.5
183.2
N.A.
7
12.1
146.4
N.A.
7
10.8
116.1
N.A.
7
9.6
92.1
N.A.
7
8.5
73.0
N.A.
7
7.6
57.9
N.A.
7
6.8
45.9
N.A.
7
6.0
36.4
N.A.
7
5.4
28.9
N.A.
7
4.8
22.9
N.A.
7
4.3
18.2
N.A.
7
3.8
14.4
N.A.
7
3.4
11.4
N.A.
7
3.0
9.1
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
Page 2 of 10
Total Area of
Strands
(C.M.)
999,424.0
900,497.3
799,725.3
750,227.4
699,695.0
600,279.0
499,590.3
400,192.0
350,289.7
299,700.0
250,003.1
211,474.8
167,884.0
133,108.1
105,454.8
83,770.2
66,407.3
52,618.2
41,718.9
33,134.1
26,218.1
20,791.8
16,533.7
13,063.7
10,375.8
8,227.9
6,511.8
5,163.8
4,099.5
3,250.8
2,580.5
2,046.3
1,617.3
1,282.5
1,024.9
812.7
644.5
511.1
405.3
321.4
254.8
202.1
160.3
127.1
100.8
79.9
63.4
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
Tables.xls : Table 2
TABLE 3 - Number of Strands per Layer
n = # of
1st Layer 2nd Layer 3rd Layer 4th Layer 5th Layer 6th Layer 7th Layer 8th Layer Total # of
Layers on
Core
Core Only of Strands of Strands of Strands of Strands of Strands of Strands of Strands of Strands Strands*
0
1
2
3
4
5
6
7
8
1
1
1
1
1
1
1
1
1
6
6
6
6
6
6
6
6
12
12
12
12
12
12
12
18
18
18
18
18
18
24
24
24
24
24
30
30
30
30
36
36
36
42
42
48
1
7
19
37
61
91
127
169
217
*The formula for the total number of strands based on the number of layers is [3n * (n +1)] +1 = 3n2 + 3n + 1 where n = # of layers.
Printed 1/21/2009 1:30 PM
Tables.xls : Table 3
Page 3 of 10
TABLE 4 - Each Strand Is
0.8905 * Next-Larger Strand
Stranded
Wire Gage
4/0
3/0
2/0
1/0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Printed 1/21/2009 1:30 PM
19-Strand
Diameters
105.5
94.0
83.7
74.5
66.4
7-Strand
Diameters
97.4
86.7
77.2
68.8
61.2
54.5
48.6
43.2
38.5
34.3
30.5
27.2
24.2
21.6
19.2
17.1
15.2
13.5
12.1
10.8
9.6
8.5
7.6
6.8
6.0
5.4
4.8
4.3
3.8
3.4
3.0
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
Page 4 of 10
Tables.xls : Table 4
Table 5 - Ratio Between Bare Solid &
Stranded Conductors Outside Diam.
# of
# of
Strands Layers
7
19
37
61
91
127
169
217
Printed 1/21/2009 1:30 PM
1
2
3
4
5
6
7
8
Ratio of
Stranded /
Solid O.D.
1.134
1.147
1.151
1.152
1.153
1.154
1.154
1.154
Tables.xls : Table 5
How They
Did It
3/
5/
7/
9/
11 /
13 /
15 /
17 /
7
19
37
61
91
127
169
217
Page 5 of 10
Table 6 - Depth of Penetration at Various Frequencies
Freq. (Hz):
1
50
60
100
1,000
10,000
100,000
1,000,000
Printed 1/21/2009 1:30 PM
Depth of Penetration ( ):
0.06609
0.00935
0.00853
0.00661
0.00209
0.00066
0.00021
0.00007
meters
meters
meters
meters
meters
meters
meters
meters
66.0855
9.3459
8.5316
6.6085
2.0898
0.6609
0.2090
0.0661
Tables.xls : Table 6
mm
mm
mm
mm
mm
mm
mm
mm
2.6018
0.3679
0.3359
0.2602
0.0823
0.0260
0.0082
0.0026
inches
inches
inches
inches
inches
inches
inches
inches
Page 6 of 10
Table 7 - Sch. 40 Copper Bus Pipe
Printed 1/21/2009 1:30 PM
1" Sch. 40 Copper
Outer Diameter
Wall Thickness
Conductive Area:
Conductive Area:
1.315
0.127
0.474
603,810.1
inches
inches
sq. in.
cir. mils
2" Sch. 40 Copper
Outer Diameter
Wall Thickness
Conductive Area:
Conductive Area:
2.375
0.157
1.094
1,393,610.5
inches
inches
sq. in.
cir. mils
2.5" Sch. 40 Copper
Outer Diameter
Wall Thickness
Conductive Area:
Conductive Area:
2.875
0.188
1.587
2,021,648.9
inches
inches
sq. in.
cir. mils
3" Sch. 40 Copper
Outer Diameter
Wall Thickness
Conductive Area:
Conductive Area:
3.500
0.219
2.257
2,875,613.8
inches
inches
sq. in.
cir. mils
Tables.xls : Table 7
Page 7 of 10
Up
3 Gages
4/0 AWG
1/0 AWG
Ratio
Area
(C.M.)
211,600
105,560
2.005
Printed 1/21/2009 1:30 PM
Solid Diam.
(mils)
460.0
324.9
1.416
Down
3 Gages
3 AWG
1/0 AWG
Ratio
Tables.xls : Example 4
Area
(C.M.)
52,624
105,560
0.499
Solid Diam.
(mils)
229.4
324.9
0.706
Page 8 of 10
Up
6 Gages
4 AWG
10 AWG
Ratio
Area
(C.M.)
41,738
10,384
4.020
Printed 1/21/2009 1:30 PM
Solid Diam.
(mils)
204.3
101.9
2.005
Down
6 Gages
16 AWG
10 AWG
Ratio
Tables.xls : Example 5
Area
(C.M.)
2,581
10,384
0.249
Solid Diam.
(mils)
50.8
101.9
0.499
Page 9 of 10
Up
10 Gages
1/0 AWG
10 AWG
Ratio
Area
(C.M.)
105,560
10,384
10.166
Printed 1/21/2009 1:30 PM
Solid Diam.
(mils)
324.9
101.9
3.188
Down
10 Gages
20 AWG
10 AWG
Ratio
Tables.xls : Example 6
Area
(C.M.)
1,024
10,384
0.099
Solid Diam.
(mils)
32.0
101.9
0.314
Page 10 of 10