©
2017 Sensata Technologies
Page 30
Installation
Table 2-2, Allowable Conductor Ampacities
The table below shows the allowable ampacities of insulated copper conductors rated 0
through 2000 volts, 60°C through 90°C, not more than three current-carrying conductors in
a raceway, cable, or earth (directly buried), based on ambient temperature of 30°C (86°F).
Conductor Size
(AWG)
Ampacity for Temperature Rating Copper Conductor
60°C (140°F)
75°C (167°F)
90°C (194°F)
14* 15
20
25
12*
20
25
30
10*
30
35
40
8
40
50
55
6
55
65
75
4
70
85
95
3
85
100
115
2
95
115
130
1
110
130
145
Data taken from Table 310.15(B)(16) in the National Electrical Code® (2014 Edition)
* Per
NEC
® (2014 Edition), Section
240.4(D) for
conductor overcurrent protection limitations. T
he
overcurrent protection of these copper conductors after any correction factors have been applied
for ambient temperature or number of conductors are limited to the following ratings: 14 AWG -
15A, 12 AWG - 20A, 10 AWG - 30A.
Table 2-3, Ambient Temperature Adjustments
Conductor ampacities must be derated when in ambient temperatures greater than
30°C (86°F). Find the allowable ampacities speci
fi
ed in the ampacity tables (from
Table 2-2) and multiply by the appropriate correction factor shown below.
Ambient Temperature
Temperature Rating of Conductor
(°C)
(°F)
60°C (140°F)
75°C (167°F)
90°C (194°F)
10 or less
50 or less
1.29
1.20
1.15
11–15
51 - 59
1.22
1.15
1.12
16 -20
60 - 68
1.15
1.11
1.08
21 - 25
69 - 77
1.08
1.05
1.04
26 - 30
78 - 86
1.00
1.00
1.00
31 - 35
87 - 95
0.91
0.94
0.96
36 - 40
96 - 104
0.82
0.88
0.91
41 - 45
105 - 113
0.71
0.82
0.87
46 - 50
114 - 122
0.58
0.75
0.82
51 - 55
123 - 131
0.41
0.67
0.76
56 - 60
132 - 140
-
0.58
0.71
61 - 65
141 - 149
-
0.47
0.65
66 - 70
150 - 158
-
0.33
0.58
71 - 75
159- 167
-
-
0.50
76 - 80
168 - 176
-
-
0.41
81 - 85
177 - 185
-
-
0.29
Data taken from Table 310.15(B)(2)(a) in the National Electrical Code® (2014 Edition)
