Specifications

9/27/01 AC 43.13-1B CHG 1
Par 11-66 Page 11-23
Where:
T
1
= Ambient Temperature
T
2
= Estimated Conductor Temperature
T
R
= Conductor Temperature Rating
I
2
= Circuit Current (A=Amps)
I
max
= Maximum Allowable Current
(A=Amps) at
T
R
This formula is quite conservative and will typi-
cally yield somewhat higher estimated tempera-
tures than are likely to be encountered under actual
operating conditions.
Note: Aluminum wire-From Table 11-9 and
11-10 note that the conductor resistance of
aluminum wire and that of copper wire (two
numbers higher) are similar. Accordingly,
the electric wire current in Table 11-9 can
be used when it is desired to substitute alu-
minum wire and the proper size can be se-
lected by reducing the copper wire size by
two numbers and referring to Table 11-10.
The use of aluminum wire size smaller than
No. 8 is not recommended.
TABLE 11-9. Current carrying capacity and resistance of copper wire.
Wire
Size
Continuous duty current (amps)-Wires in bundles,
groups, harnesses, or conduits. (See Note #1)
Max. resistance
ohms/1000ft@20 °C
Nominal
conductor
Wire Conductor Temperature Rating tin plated conduc-
tor
area -
105 °C 150 °C 200 °C (See Note #2) circ.mils
24
22
20
18
16
14
12
10
8
6
4
2
1
0
00
000
0000
2.5
3
4
6
7
10
13
17
38
50
68
95
113
128
147
172
204
4
5
7
9
11
14
19
26
57
76
103
141
166
192
222
262
310
5
6
9
12
14
18
25
32
71
97
133
179
210
243
285
335
395
28.40
16.20
9.88
6.23
4.81
3.06
2.02
1.26
0.70
0.44
0.28
0.18
0.15
0.12
0.09
0.07
0.06
475
755
1,216
1,900
2,426
3,831
5,874
9,354
16,983
26,818
42,615
66,500
81,700
104,500
133,000
166,500
210,900
Note #1: Rating is for 70°C ambient, 33 or more wires in the bundle for sizes 24 through 10, and 9
wires for size 8 and larger, with no more than 20 percent of harness current carrying capacity being used,
at an operating altitude of 60,000 feet. For rating of wires under other conditions or configurations see
paragraph 11-69.
Note #2: For resistance of silver or nickel-plated conductors see wire specifications.