Generac Power Systems Stationary Emergency Generator Installation Manual page 23

TABLE 4 — ALLOWABLE AMPACITIES OF INSULATED CONDUCTORS RATED 0-2000 VOLTS, 60° TO 90° C (140° TO 194° F).
NOT MORE THAN THREE CONDUCTORS IN RACEWAY OR CABLE OR EARTH (DIRECTLY BURIED), BASED ON
AMBIENT TEMPERATURE OF 30° C (86° F) (REFERENCE NEC TABLE 310-16)
SIZE
60° C
(140° F)
TYPES
TW¥, UF¥
AWG
kcmil
18 —
16 —
14 20¥
12 25¥
10 30
8 40
6 55
4 70
3 85
2 95
1 110
1/0 125
2/0 145
3/0 165
4/0 195
250 215
300 24
350 260
400 280
500 320
600 355
700 385
750 400
800 410
900 435
1000 455
1250 495
1500 520
1750 545
2000 560
¥ Unless otherwise specifically permitted in the NEC, the over current protection for conductor types marked with an ¥ shall not exceed 15 amperes for No.
14, 20 amperes for No. 12, and 30 amperes for No. 10 copper; or 15 amperes for No. 12 and 25 amperes for No. 10 aluminum and copper-clad aluminum
after any correction factors for ambient temperature and number of conductors have been applied.
TEMPERATURE RATING OF CONDUCTOR
75° C 90° C
(167° F) (194° F)
TYPES TYPES
FEPW¥ TA, TBS, SA
RH¥, RHW¥ SIS, FEP¥
THHW¥ FEPB¥
THW¥ RHH¥, RHW2
THWN¥ THHN¥, THHW¥
XHHW¥ THW2, THWN2
USE¥, ZW¥ USE2, XHH
XHHW¥
XHHW2, ZW2
COPPER
—
—
20¥ 25¥
25¥ 30¥
35¥ 40¥
50
65
85
100 110
115 130
160 150
150 170
175 195
200 225
230 260
255 290
285 320
310 350
335 380
380 430
42 475
460 520
475 535
490 555
520 585
545 615
590 665
625 705
650 735
665 750
60° C
(140° F)
TYPES
TW¥
UF¥
ALUMINUM OR COPPER CLAD ALUMINUM
14 —
18 —
—
20¥
25
55 30
75 40
95 55
65
75
85
100
115
130
150
170
190
210
225
260
285
310
320
330
355
375
405
435
455
470
SIZE
75° C 90° C
(167° F) (194° F)
TYPES TYPES
RH¥, RHW¥ TA, TBS
THHW¥ SA, SIS,
THW¥ THHN¥
THWN¥ THHW¥
XHHW¥ THW2, THWN2
USE¥ RHH¥, RHW2
USE2
XHH, XHHW
XHHW2, ZW2
— —
— —
— —
20¥ 25¥
30¥ 35¥
40 45
50 60
65 75
75 85
90 100
100 115
120 135
135 150
155 175
180 205
205 230
230 255
250 280
270 305
310 350
340 385
375 420
385 435
395 450
425 480
445 500
485 545
520 585
545 615
560 630
Operation
AWG
—
—
—
12
10
8
6
4
3
2
1
1/0
2/0
3/0
4/0
250
300
350
400
500
600
700
750
800
900
1000
1250
1500
1750
2000
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