Appendix
Author: E.E. Kimberly
|
TABLE A - ALLOWABLE CURRENT- CARRYING CAPACITIES OF CONDUCTORS IN AMPERES Not More Than Three Conductors in Raceway or Cable
(Based on Room Temperature of 30 C. 86 F.)
|
|
Size AWG MCM
|
Rubber TypeR Type RW TypeRU
(14-6)
|
Rubber Type RH
|
Paper
|
Asbestos Var-Cam Type AVA Type AVL
|
Impregnated Asbestos Type AI (14-8) Type AIA
|
Asbestos Type A (14-8) Type AA
|
|
Thermoplastic Asbestos Type TA
|
|
Thermoplastic TypeT (14-4/0) TypeTW (14^/0)
|
Var-Cam TypeV
|
|
Asbestos Var-Cam Type AVB
|
|
14 12 10
8
|
15 20 30 40
|
15 20 30 45
|
25 30 40 50
|
30 35
45 60
|
30 40 50 65
|
30 40 55
70
|
|
6 4 3 2 1
|
55
70 80 95 110
|
65 85 100 115 130
|
70 90 105 120 140
|
80 105 120 135 160
|
85 115 130 145 170
|
95 120 145 165 190
|
|
0
00 000 0000
|
125 145 165 195
|
150 175 200 230
|
}55 185 210 235
|
190 215 245 275
|
200 230 265 310
|
225 250
285 340
|
|
250 300 350 400 500
|
215 240 260 280 320
|
255 285 310 335 380
|
270 300 325 360 405
|
315 345 390 420 470
|
335 380 420 450 500
|
...
|
|
600 700 750 800 900
|
355
385 400 410 435
|
420 460 475 490 520
|
455 490 500 515 555
|
525 560 580 600
|
545 600 620 640
|
|
|
1,000 1,250 1,500 1,750 2,000
|
455 495 520 545 560
|
545 590 625 650 665
|
585 645 700 735
775
|
680 785 840
|
730
|
...
|
|
CORRECTION FACTOR FOR ROOM TEMPERATURES OVER 30 C. 86 F.
|
|
C F
40 104 45 113 50 122 55 131
|
.82 .71 .58 .41
|
.88 .82 .75 .67
|
.90
.85 .80
.74
|
.94 .90
.87 .83
|
.95 , .92 .89 .86
|
...
|
|
60 140 70 158 75 167 80 176
|
...
|
.58 .35
|
.67 .52 .43 .30
|
.79 .71 .66 .61
|
.83 .76 .72 .69
|
.91
.87 .86 .84
|
|
90 194 100 212
120 248 140 284
|
...
|
...
|
...
|
.50
|
.61 .51
|
.80 .77 .69 .59
|
|
TABLE B - ALLOWABLE CURRENT-CARRYING CAPACITIES OF CONDUCTORS IN AMPERES Single Conductor in Free Air
(Based on Room Temperature of 30 C. 86 F.)
|
|
Size AWG MCM
|
Rubber Type R TypeRW Type RU (14-6)
|
Rubber TypeRH
|
Thermoplastic Asbestos Type TA
|
Asbestos Var-Cam Type AVA Type AVL
|
Impregnated Asbestos
typeAI
(14-8)
Type AIA
|
Asbestos
Type A
(14-8)
Type AA
|
Slow-Burning Type SB
|
|
Var-Cam Type V
|
Weatherproof TypeWP Type SBW
|
|
Thermoplastic TypeT Type TW
|
Asbestos Var-Cam Type AVB
|
|
14 12
10 8
|
20 25 40 55
|
20 25 40
65
|
30
40 55 70
|
40 50 65
85
|
40 50 70 90
|
45 55 75 100
|
30 40 55 70
|
|
6
4 3 2
1
|
80 105 120 140 165
|
95 125 145 170 195
|
100 135 155 180 210
|
120 160 180 210 245
|
125 170 195 225 265
|
135 180 210 240 280
|
100 130 150 175 205
|
|
0 00 000 0000
|
195 225 260 300
|
230
265 310 360
|
245 285 330 385
|
285
330 385 445
|
305 355 410 475
|
325 370 430 510
|
235 275 320 370
|
|
250 300 350 400 500
|
340 375* 420 455 515
|
405 445 505 545 620
|
425 480 530 575 660
|
495 555 610 665 765
|
530 590 655 710 815
|
|
410 460 510 555 630
|
|
600 700 750 800 900
|
575 630 655 680 730
|
690 755 785 815 870
|
740 815 845 880 940
|
855 940 980 1020
|
910 1005 1045 1085
|
|
710 780 810 845 905
|
|
1,000 1,250 1,500 1,750 2,000
|
780 890 980 1070 1155
|
935 1065 1175 1280 1385
|
1000 1130 1260 1370 1470
|
1165
|
1240
|
...
|
965
1215
1405
|
|
1450
|
|
|
|
ins
|
....
|
|
|
CORRECTION FACTOR FOR ROOM TEMPERATURES OVER 30 C. 86 F.
|
|
C F 40 104 45 113 50 122 55 131
|
.82 .71 .58 .41
|
.88 .82 .75 ,67
|
.90 .85
.80 .74
|
.94 .90
.87 .83
|
.95 .92 .89 .86
|
...
|
....
|
|
60 140 70 158 75 167 80 176
|
|
.58 .35
|
.67 .52 .43 .30
|
.79 .71 .66 .61
|
.83 .76 -.72 .69
|
.91
.87 .86 .84
|
|
|
90 194 100 212 120 248 140 284
|
|
|
|
.50
|
.61 .51
|
.80 .77 .69 .59
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
FULL LOAD CURRENTS OF MOTORS
The following data are approximate full-load currents for motors of various types, frequencies, and speeds. They have been compiled from average values for representative motors of their respective classes. Variations of 10 per cent above or below the values given may be expected.
|
Hp
of
Motor
|
Amperes - Full-load Current
|
|
Direct-current Motors
|
Alternating-current Motors
|
|
Single-phase Motors
|
Squirrel-cage Induction Motors
|
Slip- ring Induction Motors
|
|
Two-phase
|
Three-phase
|
Two-phase
|
Three-phase
|
|
115-
volt
|
230-
volt
|
550-
volt
|
110-
volt
|
220-
volt
|
110-
volt
|
220-
volt
|
44O-
volt
|
550-
volt
|
2200-
volt
|
110-
volt
|
220-
volt
|
440-
volt
|
550-
volt
|
2200-
volt
|
110-
volt
|
220-
volt
|
440-
volt
|
550-
volt
|
2200-
volt
|
110-
volt
|
220-
volt
|
440-
volt
|
550-
volt
|
2200-
volt
|
|
?
|
|
|
|
7.6
|
1 R
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
4.5 6.5
|
2.3 3.3
|
"Y.4
|
8.0 9.6
|
4.0
4.8
|
4.1
4.8
|
2.1 2.4
|
1.6
1.2
|
0.9 1.0
|
|
5.0
5.4
|
2.5 2.8
|
1.3
1.4
|
i.o 1.1
|
|
|
|
|
|
|
|
|
|
|
|
|
.....
|
6.2
|
3.1
|
1.6
|
1.3
|
|
7.2
|
3.6
|
1.8
|
1.5
|
|
|
|
|
1
1 1/2
2
|
8.4 12.5 16.1
|
4.2 6.3
8.3
|
1.7 2.6 3.4
|
11.0 15.0 20.0
|
5.5 7.5 10.0
|
5.6
7.8 9.7
|
2.8 3.9 4.9
|
1.4 2.0 2.4
|
1.1 1.7 2.0
|
|
6.6 9.4 12.0
|
3.3 4.7 6
|
1.7 2.4 3.0
|
1.3 2.0 2.4
|
"•••
|
6.7 11.7 12.5
|
3.4 5.9 6.3
|
1.7 3.0 3.1
|
1.4 2.3 2.5
|
.....
|
7.8
|
3.9
|
2.0
|
1.6
|
|
|
|
|
|
14.4
|
7.2
|
3.6
|
2.9
|
|
|
|
|
|
3 5 7*
|
23 40
58
|
12.3 19.8 28.6
|
5.0
8.2 12
|
27.8 46.6 67.6
|
13.9 23.3 33.8
|
|
7.8 13 19
|
3.9 6.5 9.5
|
3.1
5.2 7.6
|
|
|
9 15
22
|
4.5 7.5 11
|
4.0 6.0 9.0
|
|
|
8.7 13.0 20.0
|
4.3 6.5 10.0
|
3.5 5.2 7.6
|
|
20.2
|
10 15
25
|
5.0 7.5 13
|
4 6 10
|
|
|
|
|
|
|
|
|
|
.....
|
|
|
|
|
10 15 20
|
75 112 149
|
38 56 74
|
16 23
31
|
86.0
|
43.0
|
....
|
24 33
45
|
11.3 16.5 22.5
|
9.4 13,2
18.2
|
|
|
27 38 52
|
14 19 26
|
11 15 21
|
|
|
24.3 39 49
|
12.1 19.5 24.7
|
10.0 15.6 19.8
|
|
|
28 45 56
|
14 23
28
|
11 18 22
|
|
|
|
|
|
|
|
|
5.0
|
|
5.7
|
|
|
|
|
|
|
|
|
|
|
25 30 40
|
185 220 294
|
92 110 146
|
38 45 61
|
|
|
|
56
67 88
|
27.7 33.5
44
|
22.2 27.0 35.5
|
6.4 7.4 9.5
|
|
64 77 101
|
32 39 51
|
26
31 40
|
7 8 10
|
|
60 72 93
|
30.0 36.0 46.5
|
24.0 28.8 37.3
|
6.4 7.8 9.5
|
|
67 82 106
|
34 41 53
|
27 33 42
|
7.5 9 11
|
|
|
|
|
|
|
|
|
|
|
50 60
75
|
364 436 540
|
180 215 268
|
75 90 111
|
|
|
|
109
129 156
|
54 65 78
|
43.5 52.0 62.5
|
12.1 13.5 16.7
|
|
125 149 180
|
63 75 90
|
50 60
72
|
13 15 19
|
|
113 135 164
|
57 68 82
|
45
54 65
|
12.1 14.0
17.3
|
|
128 150
188
|
64 75 94
|
51 60
75
|
14
16 19
|
|
|
|
|
|
|
|
|
.....
|
|
100 125 150
|
;;::;
|
357 440
|
146 184 ??0
|
|
|
|
213 270
|
107 134 156
|
87 109
125
|
21.7 27.0 31.2
|
.....
|
246 310 360
|
123 155 180
|
98 124 144
|
25 32 36
|
....
|
214
267 315
|
108 134 158
|
87 108
127
|
21.7
27 32
|
|
246 310 364
|
123
155 182
|
99 124 145
|
25 31 37
|
|
|
|
|
|
|
|
|
|
175 200
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
217
|
173
|
43.3
|
|
480
|
240
|
195
|
49
|
|
430
|
216
|
173
|
44
|
|
490
|
245
|
196
|
5*2
|
|
|
|
|
Maximum Allowable Rating of Branch Circuit Fuses
|
|
|
|
|
|
|
With Code
|
|
|
|
|
|
|
|
Letters
|
|
|
|
|
|
|
With Code Letters
|
Squirrel cage
|
|
|
|
|
|
|
Single-phase and squirrel
|
and synchro-
|
|
|
|
Minimum size conductor
|
For Running Protection of Motors
|
With Code Letters
Single-phase and squirrel
|
cage and synchronous. Full voltage, resistor or reactor starting, Code letters B to E inc.
|
nous Auto-transformer starting, Code letters B to E
|
With Code Letters
All motors
|
|
Full load current rating of motor amperes
|
in raceways For conductors in air or for other insulations see Tables A and B
|
|
cage and synchronous. Full voltage, resistor and reactor
|
Auto-transformer starting, Code letters F to R inc. Without Code Letters
|
inc. Without Code Letters
Squirrel cage
|
Code letter A. Without Code Letters
|
|
|
AWG AND MCM
|
Maxi-
|
Maximum
|
starting, Code letters F to R
|
Squirrel cage and synchronous, auto-trans-
|
and synchronous, auto-transformer
|
DC and wound-rotor
|
|
|
|
mum
|
setting
|
inc.
|
former starting, High
|
starting, High
|
motors.
|
|
|
|
rating
|
oft
|
Without Code
|
reactance squirrel
|
reactance
|
|
|
|
|
of
|
time-limit
|
Letters
|
cage.***
|
squirrel
|
|
|
|
|
|
|
N.E.C.
|
protective
|
same as above.
|
Both not more than
|
cage.***
|
|
|
|
Type R
|
TYPE
RP
|
Type
Rh
|
fuses
|
device
|
|
30 amperes
|
Both more than 30
|
|
|
|
|
|
|
Amperes
|
Amperes
|
|
|
amperes.
|
|
|
Col. No. 1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
|
1**
|
14
|
14
|
14
|
2*
|
1.25*
|
15
|
15
|
15
|
15
|
|
2**
|
14
|
14
|
14
|
3*
|
2.50*
|
15
|
15
|
15
|
15
|
|
3**
|
14
|
14
|
14
|
4*
|
3.75*
|
15
|
15
|
15
|
15
|
|
4**
|
14
|
14
|
14
|
6*
|
5.0 *
|
15
|
15
|
15
|
15
|
|
5**
|
14
|
14
|
14
|
8*
|
6.25*
|
15
|
15
|
15
|
15
|
|
6**
|
14
|
14
|
14
|
8*
|
7.50*
|
20
|
15
|
15
|
15
|
|
7
|
14
|
14
|
14
|
10*
|
8.75*
|
25
|
20
|
15
|
15
|
|
8
|
14
|
14
|
14
|
10*
|
10.0 *
|
25
|
20
|
20
|
15
|
|
9
|
14
|
14
|
14
|
12*
|
11.25*
|
30
|
25
|
20
|
15
|
|
10
|
14
|
14
|
14
|
15*
|
12.50*
|
30
|
25
|
20
|
15
|
|
11
|
14
|
14
|
14
|
15*
|
13.75*
|
35
|
30
|
25
|
20
|
|
12
|
14
|
14
|
14
|
15
|
15.00
|
40
|
30
|
25
|
20
|
|
13
|
12
|
14
|
14
|
20
|
16.25
|
40
|
35
|
30
|
20
|
|
14
|
12
|
14
|
14
|
20
|
17.50
|
45
|
35
|
30
|
25
|
|
15
|
12
|
12
|
14
|
20
|
18.75
|
45
|
40
|
30
|
25
|
|
16
|
12
|
12
|
14
|
20
|
20.00
|
50
|
40
|
35
|
25
|
|
17 18 19 20
|
10 10 10 10
|
12 12 10 10
|
14 12 12 12
|
25 25 25 25
|
21.25 22.50 23.75 25.0
|
60 60 60 60
|
45 45 50 50
|
35 40 40 40
|
30 30 30 30
|
|
22 24 26 28
|
8 8 8 8
|
10 10 8
8
|
10 10 10 10
|
30 30 35 35
|
27.50 30.00 32,50 35.00
|
70 80 80 90
|
60 60 70 70
|
45 50 60 60
|
35 40 40 45
|
|
30
32 34 36
|
6 6 6 6
|
8 8 6 6
|
8 8 8 8
|
40 40
45 45
|
37.50 40.00 42,50 45.00
|
90 100 110 110
|
70 80 90 90
|
60 70 70 80
|
45 50 60 60
|
|
38 40 42
44
|
5 5 5 4
|
6 6 6
5
|
8 6 6 6
|
50 50 50 60
|
47.50 50.00 52.50 55.0
|
125 125 125 125
|
100 100 110 110
|
80 80 90 90
|
60 60 70 70
|
|
46
48 50
52 54
|
4
4 3 3 3
|
5 5 5 4 4
|
6 6 6 6
5
|
60 60 60 70 ' 70
|
57.50 60.0 62,50 65.0 67.50
|
150 150 150
175 175
|
125 125 125 150 150
|
100 100 100 110
110
|
70 80 80 80 90
|
|
56 58 60 62
|
2 2 2 2
|
4 3 3 3
|
5 5 5 4
|
70 70 80 80
|
70.00 72.50 75.00 77.50
|
175 175 200 200
|
150 150 150
175
|
120 120 120
125
|
90 90 90 100
|
|
64 66 68 70
|
2 1 1
1
|
3 3
2 2
|
4 4 4 3
|
80 80 90 90
|
80.00 82.50 85.00 87.50
|
200 200
225 225
|
175
175 175 175
|
150 150 150 150
|
100 100 110 110
|
|
72 74 76 78
|
1 0 0 0
|
2
2 2 1
|
3 3 3 3
|
90 90 100 100
|
90.00 92.50 95.00 97.50
|
225 225 250 250
|
200 200 200 200
|
150 150
175 175
|
110 125 125
125
|
* For running protection of motors of 1 horsepower or less, see section 4322 of National Electric Code.
** For the grouping of small motors under the protection of a single set of fuses, see section 4343 of National Electric Code. *** High-reactance squirrel-cage motors are those designed to limit the starting current by means of deep-slot secondaries or double-wound secondaries
and are generally started on full voltage.
|
17 18 19 20
|
10 10 10 10
|
12 12 10 10
|
14 12 12 12
|
25 25 25 25
|
21.25 22.50 23.75 25.0
|
60 60 60 60
|
45 45 50 50
|
35 40 40 40
|
30 30 30 30
|
|
22 24 26 28
|
8 8 8 8
|
10 10 8
8
|
10 10 10 10
|
30 30 35 35
|
27.50 30.00 32,50 35.00
|
70 80 80 90
|
60 60 70 70
|
45 50 60 60
|
35 40 40 45
|
|
30
32 34 36
|
6 6 6 6
|
8 8 6 6
|
8 8 8 8
|
40 40
45 45
|
37.50 40.00 42,50 45.00
|
90 100 110 110
|
70 80 90 90
|
60 70 70 80
|
45 50 60 60
|
|
38 40 42
44
|
5 5 5 4
|
6 6 6
5
|
8 6 6 6
|
50 50 50 60
|
47.50 50.00 52.50 55.0
|
125 125 125 125
|
100 100 110 110
|
80 80 90 90
|
60 60 70 70
|
|
46
48 50
52 54
|
4
4 3 3 3
|
5 5 5 4 4
|
6 6 6 6
5
|
60 60 60 70 ' 70
|
57.50 60.0 62,50 65,0 67.50
|
150 150 150
175 175
|
125 125 125 150 150
|
100 100 100 110
110
|
70 80 80 80 90
|
|
56 58 60 62
|
2 2 2 2
|
4 3 3 3
|
5 5 5 4
|
70 70 80 80
|
70.00 72.50 75.00 77.50
|
175 175 200 200
|
150 150 150
175
|
120 120 120
125
|
90 90 90 100
|
|
64 66 68 70
|
2 1 1
1
|
3 3
2 2
|
4 4 4 3
|
80 80 90 90
|
80.00 82.50 85.00 87.50
|
200 200
225 225
|
175
175 175 175
|
150 150 150 150
|
100 100 110 110
|
|
72 74 76 78
|
1 0 0 0
|
2
2 2 1
|
3 3 3 3
|
90 90 100 100
|
90.00 92.50 95.00 97.50
|
225 225 250 250
|
200 200 200 200
|
150 150
175 175
|
110 125 125
125
|
|
* For running protection of motors of 1 horsepower or less, see section 4322 of National Electric Code. ** For the grouping of small motors under the protection of a single set of fuses, see section 4343 of National Electric Code. *** High-reactance squirrel-cage motors are those designed to limit the starting current by means of deep-slot secondaries or double-wound secondaries
and are generally started on full voltage.
|
CONDUCTOR SIZES AND OVERCURRENT PROTECTION FOR MOTORS - Continued
|
|
|
|
Maximum Allowable Rating of Branch Circuit Puses
|
|
|
|
|
|
|
With Code
|
|
|
|
|
|
|
|
Letters
|
|
|
|
|
|
|
With Code Letters
|
Squirrel cage
|
|
|
Full load current rating of motor amperes
|
Minimum size conductor in raceways For conductors in air or for other insulations see Tables A and B
AWG AND MCM
|
For Running Protection of Motors
|
With Code Letters
Single-phase and squirrel cage and synchronous. Full voltage, resistor and reactor starting, Code letters F to R inc. Without Code
|
Single-phase and squirrel cage and synchronous. Full voltage, resistor or reactor starting, Code letters B to E inc. Auto- transformer starting, Code letters F to R inc. Without Code Letters Squirrel cage and synchronous, auto-transformer starting, High reactance squirrel
|
and synchronous Auto-transformer starting, Code letters B to E inc. Without Code Letters Squirrel cage and synchronous, auto- transformer starting, High reactance
|
With Code Letters
All motors Code letter A. Without Code Letters DC and wound-rotor motors.
|
|
Maximum rating
|
Maximum setting of
|
|
|
|
of
|
time-limit
|
Letters
|
cage.***
|
squirrel
|
|
|
|
|
|
|
N.E.C.
|
protective
|
same as above.
|
Both not more than
|
cage.***
|
|
|
|
Type R
|
Type Rp
|
Type RP
|
fuses
|
device
|
|
30 amperes
|
Both more than 30
|
|
|
|
|
|
|
Amperes
|
Amperes
|
|
|
amperes.
|
|
|
Col. No. 1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
|
80
|
0
|
1
|
2
|
100
|
100.00
|
250
|
200
|
175
|
125
|
|
82
|
0
|
1
|
2
|
110
|
102.50
|
250
|
225
|
175
|
125
|
|
84
|
0
|
1
|
2
|
110
|
105.00
|
250
|
225
|
175
|
150
|
|
86
|
00
|
1
|
2
|
110
|
107.50
|
300
|
225
|
175
|
150
|
|
88
|
00
|
1
|
2
|
110
|
110.00
|
300
|
225
|
200
|
150
|
|
90
|
00
|
0
|
2
|
110
|
112.50
|
300
|
225
|
200
|
150
|
|
92
|
00
|
0
|
2
|
125
|
115.00
|
300
|
250
|
200
|
150
|
|
94
|
00
|
0
|
1
|
125
|
117.50
|
300
|
250
|
200
|
150
|
|
96
|
00
|
0
|
1
|
125
|
120.00
|
300
|
250
|
200
|
150
|
|
98
|
000
|
0
|
1
|
125
|
122.50
|
300
|
250
|
200
|
150
|
|
100
|
000
|
0
|
1
|
125
|
125.00
|
300
|
250
|
200
|
150
|
|
105
|
000
|
00
|
1
|
150
|
131.5
|
350
|
300
|
225
|
175
|
|
110
|
000
|
00
|
0
|
150
|
137.5
|
350
|
300
|
225
|
175
|
|
115
|
0000
|
00
|
0
|
150
|
144.0
|
350
|
300
|
250
|
175
|
|
120
|
0000
|
000
|
0
|
150
|
150.0
|
400
|
300
|
250
|
200
|
|
125
|
0000
|
000
|
00
|
175
|
156.5
|
400 ! 350
|
250
|
200
|
|
130 135 140 145 150
|
250 250 250 300 300
|
000 0000 0000 0000 0000
|
00 00 000 000 000
|
175 175 175 200 200
|
162.5 169.0 175.0 181.5
187.5
|
400 450 450 450 450
|
350 350 350 400 400
|
300 300 300 300 300
|
200 225 225 225 225
|
|
155 160 165 170
|
300 350 350 350
|
0000 250 250 250
|
000 000 0000 0000
|
200 200 225 225
|
194.0 200.0 206. 213.
|
500 500 500 500
|
400 400 450 450
|
350 350 350 350
|
250 250 250 300
|
|
175 180 185 190
|
400 400 400 500
|
300 300 300 300
|
0000 0000 0000 250
|
225 225 250 250
|
219. 225. 231. 238.
|
600 600 600 600
|
450 450 500 500
|
350 400 400 400
|
300 300 300 300
|
|
195 200 210 220
|
500 500 500 600
|
350 350 400 400
|
250 250 300 300
|
250 250 250 300
|
244. 250. 263.
275.
|
600 600
|
500 500 600 600
|
400 400 450 450
|
300 300 350 350
|
|
230 240 250 260
|
600 700 700 750
|
500 500 500 600
|
300 350 350 400
|
300 300 300 350
|
288. 300. 313. 325.
|
|
600 600
|
500 500 500 600
|
350 400 400 400
|
|
270 280 290 300 320
|
800 900 900 1000 1250
|
600 600 700 700 750
|
400 500 500 500 600
|
350 350 350 400 400
|
338. 350. 363.
375. 400.
|
|
|
600 600 600 600
|
450 450 450 450 500
|
|
340 360 380 400
|
1500 1750
|
900 1000 1250 1500
|
600 700 750 900
|
450 450 500 500
|
425. 450.
475. 500.
|
|
|
...
|
600 600 600 600
|
|
420 440 460
|
....
|
1500 1750
|
1000 1250 1250
|
600 600 600
|
525. 550. 575.
|
|
|
|
|
|
480
|
|
|
1500
|
600
|
600.
|
|
|
|
|
|
500
|
|
|
1500
|
|
625.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
ROUND COPPER WIRE
|
Gage No.
|
Bare Diameter
|
Circular Mils
|
Square Inch
|
Ohms per 1000 feet 25° C.
|
Weight in Ib per 1000 ft.
|
|
27
|
.0142
|
202
|
.000158
|
52.6
|
.609
|
|
26
|
.0159
|
253
|
.000199
|
417
|
767
|
|
25
|
.0179
|
320
|
.000252
|
33.0
|
.971
|
|
24
|
.0201
|
404
|
.000317
|
26.2
|
1.22
|
|
23
|
.0226
|
511
|
.000401
|
207
|
1.54
|
|
22
|
.0254
|
645
|
.000507
|
16.4
|
1.95
|
|
21
|
.0285
|
812
|
.000638
|
13.0
|
2.46
|
|
20
|
.032
|
1020
|
.000804
|
10.3
|
3.10
|
|
19
|
.036
|
1300
|
.00102
|
8.14
|
3.93
|
|
18
|
.040
|
1600
|
.00126
|
6.59
|
4.85
|
|
17
|
.045
|
2030
|
.00159
|
5.22
|
6.12
|
|
16
|
.051
|
2600
|
.00204
|
4.07
|
7.86
|
|
15
|
.057
|
3250
|
.00255
|
3.26
|
9.82
|
|
14
|
.064
|
4100
|
.00322
|
2.58
|
12.4
|
|
13
|
.072
|
5180
|
.00407
|
2.04
|
157
|
|
12
|
.081
|
6560
|
.00515
|
1.61
|
19.8
|
|
11
|
.091
|
8280
|
.00650
|
1.28
|
25.0
|
|
10
|
.102
|
10400
|
.00817
|
1.02
|
31.5
|
|
9
|
.114
|
13000
|
.0102
|
.814
|
39.3
|
|
8
|
.129
|
16600
|
.0131
|
.634
|
50.5
|
|
7
|
.144
|
20700
|
.0163
|
.510
|
62.8
|
|
6
|
.162
|
26200
|
.0206
|
.403
|
79.4
|
|
5
|
.182
|
33100
|
.0260
|
.319
|
100.
|
|
4
|
.204
|
41600
|
.0327
|
.254
|
126.
|
|
3
|
.229
|
52400
|
.0412
|
.202
|
159.
|
|
2
|
.258
|
66600
|
.0523
|
.159
|
201.
|
|
0
|
.325
|
106000
|
.0830
|
.100
|
320.
|
|
2/0
|
.365
|
133000
|
.105
|
.0791
|
404.
|
|
4/0
|
.460
|
212000
|
.166
|
.0500
|
650.
|
 |
| Fig. A-l. Magnetization Curves
|
MULTIPLYING FACTORS FOR CONVERTING D-C RESISTANCE OF LARGE CONDUCTORS AND CABLES TO A-C RESISTANCE
|
Conductor Size in Circular Mils
|
Multiplying Factor
|
|
25 Cycles
|
60 Cycles
|
|
250,000
|
|
1.005
|
|
300,000
|
|
1.006
|
|
350,000
|
|
1.009
|
|
400,000
|
|
1.011
|
|
500,000
|
|
1.018
|
|
600,000
|
1.005
|
1.025
|
|
700,000
|
1.006
|
1.034
|
|
750,000
|
1.007
|
1.039
|
|
800,000
|
1.008
|
1.044
|
|
900,000
|
1.010
|
1.055
|
|
1,000,000
|
1.012
|
1.067
|
|
1,250,000
|
1.019
|
1.102
|
|
1,500,000
|
1.027
|
1.142
|
|
1,750,000
|
1.037
|
1.185
|
|
2,000,000
|
1.048
|
1.233
|
|
Appendix
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