Suggested Ampacities
Assigning a current rating to a wire is really a problem of wire transfer. The watts generated at the conductor must be dissipated through the insulation to the ambient without overheating the
conductor or insulation.
While current ratings for power cables have been officially assigned by such groups as the Insulated Cable Engineers Association and the National Electric Code, no such ratings have been officially
developed for appliance wires or apparatus cables.
Since appliance and apparatus designs vary widely, any effort to standardize actual current ratings is just about impossible.
SUGGESTED AMPACITIES (All Types of Single Conductor Insulation)
AWG
80C
90C
30
28
26
24
22
20
18
16
14
12
10
2
3
4
6
8
10
15
18
20
25
35
3
4
5
7
9
12
16
20
25
30
40
30
40
50
60
70
80
90
100
125
150
200
1.00
.88
.75
.58
.35
-
1.00
.90
.80
.67
.52
.30
-
105C
125C
150C
200C
250C*
3
5
6
8
12
15
22
29
40
50
70
4
6
7
10
13
17
24
32
45
55
75
4
6
8
11
14
19
29
37
39
54
73
1.00
.96
.91
.87
.82
.76
.71
.65
.50
-
1.00
.97
.93
.91
.87
.84
.80
.77
.66
.54
-
1.00
.98
.95
.95
.93
.90
.87
.85
.72
.65
.49
AMPERES PER CONDUCTOR
3
4
5
7
10
13
18
24
33
45
58
3
5
6
8
11
14
20
26
40
50
70
CORRECTION FACTORS FOR VARIOUS AIR TEMPERATURES
1.00
.92
.82
.73
.61
.46
.30
-
1.00
.95
.89
.83
.76
.69
.61
.51
-
Current ratings for different conductor materials may be calculated by multiplying the appropriate copper conductor ratings by the following factors:
*NICKEL PLATED COPPER: 0.87
NICKEL: 0.43
IEWC • 5001 S. Towne Drive, New Berlin, WI 53151 | Toll-Free: 800-344-2323 | Web: www.iewc.com
IEWC assumes no responsibility for the use of, or reliance on the information provided herein and disclaims all liability for any and all damages arising out of the use of, or reliance on, this information.
SUGGESTED CURRENT CARRYING CAPACITY TABLE (Base Temperature at 40C)
24
22
20
18
16
14
12
10
8
6
4
3
2
1
1/0
2/0
3/0
4/0
250
300
350
400
500
150C
Tinned Copper
200C
Tinned Copper
NPC 2% - 10%
250C
NPC 2% - 10%
250C
“A” Nickel
250C
NPI
450C
NPC - 27%
450C
“A” Nickel
6.6
9
13
17
22
34
43
55
76
96
120
143
160
186
215
251
288
332
365
414
461
495
563
7.2
9.6
14
18
24
36
45
60
83
110
125
152
171
197
229
260
297
346
385
436
486
522
593
8
10.8
15
20
26
39
54
73
93
117
148
166
191
215
244
273
308
361
398
452
503
540
613
4
5
7
9.4
12
18
25
34
43
55
69
78
90
101
114
128
144
169
187
212
236
254
288
3.3
4.4
6
8
11
16
22
30
39
49
62
69
80
90
102
114
129
151
167
190
211
226
257
9
12
18
23
30
45
56
75
104
138
162
182
210
236
268
300
338
397
-
4.3
5.6
8
11
14
21
26
35
49
65
76
85
99
110
126
141
159
186
-
NOTE: For allowable ampacities for fixture wire, please see the National Electrical Code Handbook.
For ambient temperatures other than 40C (104F), multiply the ampacities shown above by the appropriate factor shown below.
WIRE TEMPERATURE RATING
Ambient Temperature
(C)
200C
250C
450C
Ambient Temperature
(F)
41-50
51-60
61-70
71-80
81-90
91-100
101-120
121-140
141-160
161-180
181-200
201-225
226-250
251-275
176-300
301-325
326-350
351-375
376-400
0.97
0.94
0.90
0.87
0.83
0.72
0.71
0.61
0.50
0.35
-
0.98
0.95
0.93
0.90
0.87
0.85
0.79
0.71
0.65
0.58
0.49
0.35
-
0.99
0.99
0.96
0.95
0.93
0.92
0.89
0.86
0.84
0.81
0.78
0.74
0.69
0.65
0.60
0.55
0.49
0.42
0.34
106-122
124-140
142-158
160-176
177-194
195-212
213-248
249-284
285-320
321-356
357-392
393-437
439-482
483-527
528-572
573-617
618-662
663-707
708-752
NOTE: The use of this table for establishing ampacity ratings is an inexact procedure. This table should only be used as a starting point when establihsing ratings for any given situations. It is
recommended that design engineers desiring accurate ampacity data study the National Electrical Code Handbook - Article 310-13-310-84.
IEWC • 5001 S. Towne Drive, New Berlin, WI 53151 | Toll-Free: 800-344-2323 | Web: www.iewc.com
IEWC assumes no responsibility for the use of, or reliance on the information provided herein and disclaims all liability for any and all damages arising out of the use of, or reliance on, this information.
SUGGESTED AMPACITIES (All Types of Insulations)
COPPER
ALUMINUM
Not More Than 3 Conductors in
Raceway or Cable
Not More Than 3 Conductors in
Raceway or Cable
Single Conductor in Free Air
CONDUCTOR TEMPERATURE RATING
AWG or MCM
85-90C
Temp
(185F)
110C
Temp
(230F)
85-90C
Temp
(185F)
CONDUCTOR TEMPERATURE RATINGS
110C
Temp
(230F)
125C
Temp
(257F)
200C
Temp
(392F)
85-90C
Temp
(185F)
110C
Temp
(230F)
AMPERES PER CONDUCTOR
(100% Load Factor)
14
12
10
8
6
4
2
1
0
00
000
0000
250
300
350
400
500
600
700
750
800
900
1000
25
30
40
55
70
95
125
145
165
190
215
250
275
310
340
365
415
460
500
515
535
565
590
30
35
45
60
80
105
135
160
190
215
245
275
315
345
390
420
470
525
560
580
600
680
30
40
55
75
100
135
185
215
250
290
335
390
440
485
550
595
675
750
825
855
885
950
1020
Single Conductor in Free Air
40
50
65
85
120
160
210
245
285
330
385
445
495
555
610
665
765
855
940
980
1020
1165
85-90C
Temp
(185F)
110C
Temp
(230F)
125C
Temp
(257F)
200C
Temp
(392F)
AMPERES PER CONDUCTOR
(100% Load Factor)
40
50
70
90
125
170
225
265
305
355
410
475
530
590
655
710
815
910
1005
1045
1085
1240
45
55
75
100
135
180
240
280
325
370
430
510
-
25
30
40
55
75
100
110
130
145
170
195
220
250
270
295
335
370
405
420
430
465
485
25
35
45
60
80
105
125
150
170
195
215
250
275
310
335
380
425
455
470
485
560
30
45
55
80
105
140
165
190
220
255
300
330
375
415
450
515
585
645
670
695
750
800
40
50
65
95
125
165
190
220
255
300
345
385
435
475
520
595
675
745
775
805
930
40
55
70
100
135
175
205
240
275
320
370
415
460
510
555
635
720
795
825
855
990
45
60
80
105
140
185
220
255
290
335
400
-
0.90
0.80
0.67
0.52
0.30
-
0.94
0.87
0.79
0.71
0.61
0.50
-
0.95
0.89
0.83
0.76
0.69
0.61
0.51
-
0.91
0.87
0.84
0.80
0.77
0.69
0.59
CORRECTION FACTORS FOR VARIOUS AMBIENT AIR TEMPERATURES
40C
50C
60C
70C
80C
90C
100C
120C
140C
0.90
0.80
0.67
0.52
0.30
-
0.94
0.87
0.79
0.71
0.61
0.50
-
0.90
0.80
0.67
0.52
0.30
-
0.94
0.87
0.79
0.71
0.61
0.50
-
0.95
0.89
0.83
0.76
0.69
0.61
0.51
-
0.91
0.87
0.84
0.80
0.77
0.69
-
0.90
0.80
0.67
0.52
0.30
0.59
0.94
0.87
0.79
0.71
0.61
0.50
-
*Based on an ambient temperature of 30C (86F)
IEWC • 5001 S. Towne Drive, New Berlin, WI 53151 | Toll-Free: 800-344-2323 | Web: www.iewc.com
IEWC assumes no responsibility for the use of, or reliance on the information provided herein and disclaims all liability for any and all damages arising out of the use of, or reliance on, this information.