30 CFR Part 18, Appendix I

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Table No.	Title
1	Portable power cable ampacities—600 volts.
2	Portable cord ampacities—600 volts.
3	Portable power cable ampacities—601 to 5,000 volts.
4	Normal diameter of round cables with tolerances in inches—600 volts.
5	Nominal dimension of flat cables with tolerances in inches—600 volts.
6	Nominal diameter of heavy jacketed cords with tolerances in inches—600 volts.
7	Nominal diameter of three-conductor portable power cables with tolerances in inches—601 to 5,000 volts.
8	Fuse ratings or instantaneous settings of circuit breakers for short-circuit protection of portable cables.
9	Specifications for portable cables longer than 500 feet.
10	High voltage trailing cable ampacities and outside diameters.
Conductor size—AWG or MCM	Single conductor \| 2-conductor, round or flat \| 3-conductor, round or flat \| 4-conductor \| 5-conductor \| 6-conductor
8	45 \| 40 \| 35 \| 30 \| 25 \| 20
6	60 \| 50 \| 50 \| 40 \| 35 \| 30
4	85 \| 70 \| 65 \| 55 \| 45 \| 35
3	95 \| 80 \| 75 \| 65 \| 55 \| 45
2	110 \| 95 \| 90 \| 75 \| 65 \| 55
1	130 \| 110 \| 100 \| 85 \| 75 \| 65
1/0	150 \| 130 \| 120 \| 100 \| 90 \| 80
2/0	175 \| 150 \| 135 \| 115 \| 105 \| 95
3/0	205 \| 175 \| 155 \| 130 \| 120 \| 110
4/0	235 \| 200 \| 180 \| 150 \| 140 \| 130
250	275 \| 220 \| 200 \| 160 \| \|
300	305 \| 240 \| 220 \| 175 \| \|
350	345 \| 240 \| 235 \| 190 \| \|
400	375 \| 280 \| 250 \| 200 \| \|
450	400 \| 300 \| 270 \| 215 \| \|
500	425 \| 320 \| 290 \| 230 \| \|
Conductor size—AWG	1-3 conductor \| 4-6 conductor \| 7-9 conductor
14	15 \| 12 \| 8
12	20 \| 16 \| 11
10	25 \| 20 \| 14
Conductor size—AWG or MCM	3-conductor types G-GC and SIIC-GC 2,000 volts \| 3-conductor type SHD-GC 2,001-5,000 volts
6	65 \| 65
4	85 \| 85
3	100 \| 100
2	115 \| 115
1	130 \| 130
1/0	145 \| 145
2/0	170 \| 170
3/0	195 \| 195
4/0	220 \| 220
250	245 \| 245
300	275 \| 275
350	305 \| 305
Conductor size—AWG or MCM	Single conductor \| 2-conductor \| 3-conductor \| 4-conductor—Types W & G \| 5-conductor—Types W & G \| 6-conductor
Types W & G twisted	Type PG, 2 power \| Type PCG, 3 power, ground \| Types W & G \| Type PG, 3 power, ground \| Type PCG, 3 power, 2 control, ground \| Type w \| Tolerance
8	0.44 \| 0.81 \| 0.84 \| 0.94 \| 0.91 \| 0.93 \| 1.03 \| 0.99 \| 1.07 \| 1.18 \| ±0.03
6	0.51 \| 0.93 \| 0.93 \| 0.98 \| 1.01 \| 1.03 \| 1.18 \| 1.1 \| 1.21 \| 1.31 \| ±.03
4	0.57 \| 1.08 \| 1.08 \| 1.1 \| 1.17 \| 1.2 \| 1.29 \| 1.27 \| 1.4 \| 1.52 \| ±.03
3	0.63 \| 1.17 \| 1.17 \| 1.2 \| 1.24 \| 1.27 \| 1.31 \| 1.34 \| 1.48 \| 1.61 \| ±.03
2	0.66 \| 1.27 \| 1.27 \| 1.29 \| 1.34 \| 1.34 \| 1.39 \| 1.48 \| 1.61 \| 1.75 \| ±.03
1	0.74 \| 1.44 \| 1.44 \| 1.44 \| 1.51 \| 1.52 \| 1.52 \| 1.68 \| 1.88 \| 2.05 \| ±.03
1/0	0.77 \| 1.52 \| 1.52 \| 1.52 \| 1.65 \| 1.68 \| 1.68 \| 1.79 \| 1.96 \| 2.13 \| ±.04
2/0	0.82 \| 1.65 \| 1.65 \| 1.65 \| 1.75 \| 1.79 \| 1.79 \| 1.93 \| 2.13 \| 2.32 \| ±.04
3/0	0.87 \| 1.77 \| 1.77 \| 1.77 \| 1.89 \| 1.93 \| 1.93 \| 2.07 \| 2.26 \| 2.49 \| ±.05
4/0	0.93 \| 1.92 \| 1.92 \| 1.92 \| 2.04 \| 2.13 \| 2.13 \| 2.26 \| 2.46 \| 2.71 \| ±.05
250	1.03 \| 2.16 \| 2.16 \| 2.16 \| 2.39 \| 2.39 \| 2.39 \| 2.66 \| \| \| ±.06
300	1.09 \| 2.32 \| \| \| 2.56 \| \| \| 2.84 \| \| \| ±.06
350	1.15 \| 2.43 \| \| \| 2.68 \| \| \| 2.98 \| \| \| ±.06
400	1.2 \| 2.57 \| \| \| 2.82 \| \| \| 3.14 \| \| \| ±.06
450	1.26 \| 2.67 \| \| \| 2.94 \| \| \| 3.26 \| \| \| ±.06
500	1.31 \| 2.76 \| \| \| 3.03 \| \| \| 3.4 \| \| \| ±.06
Conductor size—AWG	2-conductor \| 3-conductor—Type G
Type W	Type G \| Major \| Minor
Major	Minor \| Major \| Minor \| O.D. \| Tolerance \| O.D. \| Tolerance
O.D.	Tolerance \| O.D. \| Tolerance \| O.D. \| Tolerance \| O.D. \| Tolerance
8	0.84 \| ±0.04 \| 0.51 \| ±0.03 \| \| \| \| \| \| \| \|
6	0.93 \| ±.04 \| 0.56 \| ±.03 \| 1.02 \| ±.04 \| 0.56 \| ±.03 \| 1.65 \| ±0.06 \| 0.67 \| ±0.05
4	1.05 \| ±.04 \| 0.61 \| ±.03 \| 1.15 \| ±.04 \| 0.61 \| ±.03 \| 1.85 \| ±.06 \| 0.75 \| ±.05
3	1.14 \| ±.04 \| 0.68 \| ±.03 \| 1.26 \| ±.04 \| 0.68 \| ±.03 \| 1.99 \| ±.06 \| 0.77 \| ±.05
2	1.24 \| ±.04 \| 0.73 \| ±.03 \| 1.35 \| ±.04 \| 0.73 \| ±.06 \| 2.1 \| ±.06 \| 0.81 \| ±.05
1	1.4 \| ±.04 \| 0.81 \| ±.03 \| 1.55 \| ±.04 \| 0.81 \| ±.03 \| 2.43 \| ±.06 \| 0.97 \| ±.05
1/0	1.51 \| ±.04 \| 0.93 \| ±.03 \| 1.67 \| ±.04 \| 0.93 \| ±.03 \| \| \| \|
2/0	1.63 \| ±.04 \| 0.99 \| ±.03 \| 1.85 \| ±.04 \| 0.99 \| ±.03 \| \| \| \|
3/0	1.77 \| ±.04 \| 1.03 \| ±.03 \| 2 \| ±.04 \| 1.03 \| ±.03 \| \| \| \|
4/0	1.89 \| ±.04 \| 1.1 \| ±.03 \| 2.1 \| ±.04 \| 1.1 \| ±.03 \| \| \| \|
Conductor size—AWG	2-conductor \| 3-conductor \| 4-conductor \| 5-conductor \| 6-conductor \| 7-conductor
Diameter	Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance
14	0.64 \| ±0.02 \| 0.67 \| ±0.02 \| 0.71 \| ±0.02 \| 0.78 \| ±0.03 \| 0.83 \| ±0.03 \| 0.89 \| ±0.03
12	0.68 \| ±.02 \| 0.72 \| ±.03 \| 0.76 \| ±.03 \| 0.83 \| ±.03 \| 0.89 \| ±.03 \| 0.98 \| ±.03
10	0.73 \| ±.03 \| 0.8 \| ±.03 \| 0.84 \| ±.03 \| 0.9 \| ±.03 \| 1 \| ±.03 \| 1.07 \| ±.03
Conductor size—AWG or MCM	Type G-GC (nonshielded) 2,000 volts \| Type SHC-GC (shielded overall) 2,000 volts \| Type SHD-GC (individually shielded power conductors) 2,001-3,000 volts \| Type SHD-GC (individually shielded power conductors) 3,001-5,000 volts
Diameter	Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance
6	1.25 \| + 0.10, −0.06 \| 1.39 \| + 0.11, −0.07 \| 1.62 \| + 0.13, −0.08 \| 1.78 \| + 0.14, −0.09
4	1.4 \| + .11, −.07 \| 1.55 \| + .12, −.08 \| 1.77 \| + .14, −.09 \| 1.9 \| + .15, −.10
3	1.48 \| + .12, −.07 \| 1.62 \| + .13, −.08 \| 1.84 \| + .15, −.09 \| 1.98 \| + .16, −.10
2	1.55 \| + .12, −.08 \| 1.71 \| + .14, −.09 \| 1.92 \| + .15, −.10 \| 2.09 \| + .17, −.11
1	1.74 \| + .14, −.09 \| 1.89 \| + .15, −.09 \| 2.04 \| + .16, −.10 \| 2.18 \| + .17, −.11
1/0	1.84 \| + .15, −.09 \| 2.02 \| + .16, −.10 \| 2.18 \| + .17, −.11 \| 2.34 \| + .19, −.12
2/0	1.99 \| + .16, −.10 \| 2.16 \| + .17, −.11 \| 2.29 \| + .18, −.12 \| 2.46 \| + .20, −.12
3/0	2.12 \| + .17, −.11 \| 2.3 \| + .18, −.11 \| 2.45 \| + .20, −.12 \| 2.62 \| + .21, −.13
4/0	2.3 \| + .18, −.12 \| 2.48 \| + .20, −.12 \| 2.62 \| + .21, −.13 \| 2.76 \| + .22, −.14
250	2.46 \| + .20, −.12 \| 2.7 \| + .22, −.13 \| \| \| \|
300	2.63 \| + .21, −.13 \| 2.84 \| + .23, −.14 \| \| \| \|
350	2.75 \| + .22, −.14 \| 2.97 \| + .24, −.15 \| \| \| \|
Conductor size—AWG or MCM	Ohms/1,000 ft. at 25 °C. \| Maximum allowable fuse rating (amperes) \| Maximum allowable circuit breaker instantaneous setting (amperes) 1
14	2.62 \| 20 \| 50
12	1.65 \| 30 \| 75
10	1.04 \| 40 \| 150
8	0.654 \| 80 \| 200
6	0.41 \| 100 \| 300
4	0.259 \| 200 \| 500
3	0.205 \| 250 \| 600
2	0.162 \| 300 \| 800
1	0.129 \| 375 \| 1,000
1/0	0.102 \| 500 \| 1,250
2/0	0.081 \| \| 1,500
3/0	0.064 \| \| 2,000
4/0	0.051 \| \| 2,500
250	0.043 \| \| 2,500
300	0.036 \| \| 2,500
350	0.031 \| \| 2,500
400	0.027 \| \| 2,500
450	0.024 \| \| 2,500
500	0.022 \| \| 2,500

1 Higher circuit-breaker settings may be permitted for special applications when justified.

Conductor size—AWG or MCM	Max. allowable length (feet)	Normal ampacity at 60 °C. copper temperature (40 °C. ambient)	Resistance at 60 °C. copper temperature (ohms)
6	550	50	0.512
4	600	70	0.353
3	650	80	0.302
2	700	95	0.258
1	750	110	0.22
1/0	800	130	0.185
2/0	850	150	0.157
3/0	900	175	0.13
4/0	1,000	200	0.116
250	1,000	220	0.098
300	1,000	240	0.082
350	1,000	260	0.07
400	1,000	280	0.061
450	1,000	300	0.054
500	1,000	320	.050

1 Fuses shall not be used for short-circuit protection of these cables. Circuit breakers shall be used with the instantaneous trip settings not to exceed the values given in Table 8.

Power conductor	Ampacity *	Outside diameter **(inches)
Size AWG or kcmil	Amperes per conductor	SHD-GC 2001 to 5000 volts \| SHD-CGC 2001 to 5000 volts \| SHD-PCG 2001 to 5000 volts
6	93	1.56 \| 1.62 \|
4	122	1.68 \| 1.73 \|
3	140	1.78 \| 1.82 \| 1.94
2	159	1.87 \| 1.91 \| 2.03
1	184	1.95 \| 1.98 \| 2.12
1/0	211	2.08 \| 2.1 \| 2.26
2/0	243	2.2 \| 2.2 \| 2.4
3/0	279	2.36 \| 2.36 \| 2.58
4/0	321	2.5 \| 2.5 \| 2.76
250	355	2.69 \| 2.69 \|
300	398	2.81 \| 2.81 \|
350	435	2.95 \| 2.95 \|
500	536	3.31 \| 3.31 \|

* These ampacities are based on single isolated conductor in air, operated with open-circuited shield for a 90 °C conductor temperature and an ambient temperature of 40 °C.

** Tolerances for the outside diameter are + 8%/−5%.

[33 FR 4660, Mar. 19, 1968; 33 FR 6345, Apr. 26, 1968, as amended at 42 FR 8373, Feb. 10, 1977; 75 FR 17549, Apr. 6, 2010; 75 FR 20918, Apr. 22, 2010]

Table No.	Title
1	Portable power cable ampacities—600 volts.
2	Portable cord ampacities—600 volts.
3	Portable power cable ampacities—601 to 5,000 volts.
4	Normal diameter of round cables with tolerances in inches—600 volts.
5	Nominal dimension of flat cables with tolerances in inches—600 volts.
6	Nominal diameter of heavy jacketed cords with tolerances in inches—600 volts.
7	Nominal diameter of three-conductor portable power cables with tolerances in inches—601 to 5,000 volts.
8	Fuse ratings or instantaneous settings of circuit breakers for short-circuit protection of portable cables.
9	Specifications for portable cables longer than 500 feet.
10	High voltage trailing cable ampacities and outside diameters.
Conductor size—AWG or MCM	Single conductor \| 2-conductor, round or flat \| 3-conductor, round or flat \| 4-conductor \| 5-conductor \| 6-conductor
8	45 \| 40 \| 35 \| 30 \| 25 \| 20
6	60 \| 50 \| 50 \| 40 \| 35 \| 30
4	85 \| 70 \| 65 \| 55 \| 45 \| 35
3	95 \| 80 \| 75 \| 65 \| 55 \| 45
2	110 \| 95 \| 90 \| 75 \| 65 \| 55
1	130 \| 110 \| 100 \| 85 \| 75 \| 65
1/0	150 \| 130 \| 120 \| 100 \| 90 \| 80
2/0	175 \| 150 \| 135 \| 115 \| 105 \| 95
3/0	205 \| 175 \| 155 \| 130 \| 120 \| 110
4/0	235 \| 200 \| 180 \| 150 \| 140 \| 130
250	275 \| 220 \| 200 \| 160 \| \|
300	305 \| 240 \| 220 \| 175 \| \|
350	345 \| 240 \| 235 \| 190 \| \|
400	375 \| 280 \| 250 \| 200 \| \|
450	400 \| 300 \| 270 \| 215 \| \|
500	425 \| 320 \| 290 \| 230 \| \|
Conductor size—AWG	1-3 conductor \| 4-6 conductor \| 7-9 conductor
14	15 \| 12 \| 8
12	20 \| 16 \| 11
10	25 \| 20 \| 14
Conductor size—AWG or MCM	3-conductor types G-GC and SIIC-GC 2,000 volts \| 3-conductor type SHD-GC 2,001-5,000 volts
6	65 \| 65
4	85 \| 85
3	100 \| 100
2	115 \| 115
1	130 \| 130
1/0	145 \| 145
2/0	170 \| 170
3/0	195 \| 195
4/0	220 \| 220
250	245 \| 245
300	275 \| 275
350	305 \| 305
Conductor size—AWG or MCM	Single conductor \| 2-conductor \| 3-conductor \| 4-conductor—Types W & G \| 5-conductor—Types W & G \| 6-conductor
Types W & G twisted	Type PG, 2 power \| Type PCG, 3 power, ground \| Types W & G \| Type PG, 3 power, ground \| Type PCG, 3 power, 2 control, ground \| Type w \| Tolerance
8	0.44 \| 0.81 \| 0.84 \| 0.94 \| 0.91 \| 0.93 \| 1.03 \| 0.99 \| 1.07 \| 1.18 \| ±0.03
6	0.51 \| 0.93 \| 0.93 \| 0.98 \| 1.01 \| 1.03 \| 1.18 \| 1.1 \| 1.21 \| 1.31 \| ±.03
4	0.57 \| 1.08 \| 1.08 \| 1.1 \| 1.17 \| 1.2 \| 1.29 \| 1.27 \| 1.4 \| 1.52 \| ±.03
3	0.63 \| 1.17 \| 1.17 \| 1.2 \| 1.24 \| 1.27 \| 1.31 \| 1.34 \| 1.48 \| 1.61 \| ±.03
2	0.66 \| 1.27 \| 1.27 \| 1.29 \| 1.34 \| 1.34 \| 1.39 \| 1.48 \| 1.61 \| 1.75 \| ±.03
1	0.74 \| 1.44 \| 1.44 \| 1.44 \| 1.51 \| 1.52 \| 1.52 \| 1.68 \| 1.88 \| 2.05 \| ±.03
1/0	0.77 \| 1.52 \| 1.52 \| 1.52 \| 1.65 \| 1.68 \| 1.68 \| 1.79 \| 1.96 \| 2.13 \| ±.04
2/0	0.82 \| 1.65 \| 1.65 \| 1.65 \| 1.75 \| 1.79 \| 1.79 \| 1.93 \| 2.13 \| 2.32 \| ±.04
3/0	0.87 \| 1.77 \| 1.77 \| 1.77 \| 1.89 \| 1.93 \| 1.93 \| 2.07 \| 2.26 \| 2.49 \| ±.05
4/0	0.93 \| 1.92 \| 1.92 \| 1.92 \| 2.04 \| 2.13 \| 2.13 \| 2.26 \| 2.46 \| 2.71 \| ±.05
250	1.03 \| 2.16 \| 2.16 \| 2.16 \| 2.39 \| 2.39 \| 2.39 \| 2.66 \| \| \| ±.06
300	1.09 \| 2.32 \| \| \| 2.56 \| \| \| 2.84 \| \| \| ±.06
350	1.15 \| 2.43 \| \| \| 2.68 \| \| \| 2.98 \| \| \| ±.06
400	1.2 \| 2.57 \| \| \| 2.82 \| \| \| 3.14 \| \| \| ±.06
450	1.26 \| 2.67 \| \| \| 2.94 \| \| \| 3.26 \| \| \| ±.06
500	1.31 \| 2.76 \| \| \| 3.03 \| \| \| 3.4 \| \| \| ±.06
Conductor size—AWG	2-conductor \| 3-conductor—Type G
Type W	Type G \| Major \| Minor
Major	Minor \| Major \| Minor \| O.D. \| Tolerance \| O.D. \| Tolerance
O.D.	Tolerance \| O.D. \| Tolerance \| O.D. \| Tolerance \| O.D. \| Tolerance
8	0.84 \| ±0.04 \| 0.51 \| ±0.03 \| \| \| \| \| \| \| \|
6	0.93 \| ±.04 \| 0.56 \| ±.03 \| 1.02 \| ±.04 \| 0.56 \| ±.03 \| 1.65 \| ±0.06 \| 0.67 \| ±0.05
4	1.05 \| ±.04 \| 0.61 \| ±.03 \| 1.15 \| ±.04 \| 0.61 \| ±.03 \| 1.85 \| ±.06 \| 0.75 \| ±.05
3	1.14 \| ±.04 \| 0.68 \| ±.03 \| 1.26 \| ±.04 \| 0.68 \| ±.03 \| 1.99 \| ±.06 \| 0.77 \| ±.05
2	1.24 \| ±.04 \| 0.73 \| ±.03 \| 1.35 \| ±.04 \| 0.73 \| ±.06 \| 2.1 \| ±.06 \| 0.81 \| ±.05
1	1.4 \| ±.04 \| 0.81 \| ±.03 \| 1.55 \| ±.04 \| 0.81 \| ±.03 \| 2.43 \| ±.06 \| 0.97 \| ±.05
1/0	1.51 \| ±.04 \| 0.93 \| ±.03 \| 1.67 \| ±.04 \| 0.93 \| ±.03 \| \| \| \|
2/0	1.63 \| ±.04 \| 0.99 \| ±.03 \| 1.85 \| ±.04 \| 0.99 \| ±.03 \| \| \| \|
3/0	1.77 \| ±.04 \| 1.03 \| ±.03 \| 2 \| ±.04 \| 1.03 \| ±.03 \| \| \| \|
4/0	1.89 \| ±.04 \| 1.1 \| ±.03 \| 2.1 \| ±.04 \| 1.1 \| ±.03 \| \| \| \|
Conductor size—AWG	2-conductor \| 3-conductor \| 4-conductor \| 5-conductor \| 6-conductor \| 7-conductor
Diameter	Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance
14	0.64 \| ±0.02 \| 0.67 \| ±0.02 \| 0.71 \| ±0.02 \| 0.78 \| ±0.03 \| 0.83 \| ±0.03 \| 0.89 \| ±0.03
12	0.68 \| ±.02 \| 0.72 \| ±.03 \| 0.76 \| ±.03 \| 0.83 \| ±.03 \| 0.89 \| ±.03 \| 0.98 \| ±.03
10	0.73 \| ±.03 \| 0.8 \| ±.03 \| 0.84 \| ±.03 \| 0.9 \| ±.03 \| 1 \| ±.03 \| 1.07 \| ±.03
Conductor size—AWG or MCM	Type G-GC (nonshielded) 2,000 volts \| Type SHC-GC (shielded overall) 2,000 volts \| Type SHD-GC (individually shielded power conductors) 2,001-3,000 volts \| Type SHD-GC (individually shielded power conductors) 3,001-5,000 volts
Diameter	Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance \| Diameter \| Tolerance
6	1.25 \| + 0.10, −0.06 \| 1.39 \| + 0.11, −0.07 \| 1.62 \| + 0.13, −0.08 \| 1.78 \| + 0.14, −0.09
4	1.4 \| + .11, −.07 \| 1.55 \| + .12, −.08 \| 1.77 \| + .14, −.09 \| 1.9 \| + .15, −.10
3	1.48 \| + .12, −.07 \| 1.62 \| + .13, −.08 \| 1.84 \| + .15, −.09 \| 1.98 \| + .16, −.10
2	1.55 \| + .12, −.08 \| 1.71 \| + .14, −.09 \| 1.92 \| + .15, −.10 \| 2.09 \| + .17, −.11
1	1.74 \| + .14, −.09 \| 1.89 \| + .15, −.09 \| 2.04 \| + .16, −.10 \| 2.18 \| + .17, −.11
1/0	1.84 \| + .15, −.09 \| 2.02 \| + .16, −.10 \| 2.18 \| + .17, −.11 \| 2.34 \| + .19, −.12
2/0	1.99 \| + .16, −.10 \| 2.16 \| + .17, −.11 \| 2.29 \| + .18, −.12 \| 2.46 \| + .20, −.12
3/0	2.12 \| + .17, −.11 \| 2.3 \| + .18, −.11 \| 2.45 \| + .20, −.12 \| 2.62 \| + .21, −.13
4/0	2.3 \| + .18, −.12 \| 2.48 \| + .20, −.12 \| 2.62 \| + .21, −.13 \| 2.76 \| + .22, −.14
250	2.46 \| + .20, −.12 \| 2.7 \| + .22, −.13 \| \| \| \|
300	2.63 \| + .21, −.13 \| 2.84 \| + .23, −.14 \| \| \| \|
350	2.75 \| + .22, −.14 \| 2.97 \| + .24, −.15 \| \| \| \|
Conductor size—AWG or MCM	Ohms/1,000 ft. at 25 °C. \| Maximum allowable fuse rating (amperes) \| Maximum allowable circuit breaker instantaneous setting (amperes) 1
14	2.62 \| 20 \| 50
12	1.65 \| 30 \| 75
10	1.04 \| 40 \| 150
8	0.654 \| 80 \| 200
6	0.41 \| 100 \| 300
4	0.259 \| 200 \| 500
3	0.205 \| 250 \| 600
2	0.162 \| 300 \| 800
1	0.129 \| 375 \| 1,000
1/0	0.102 \| 500 \| 1,250
2/0	0.081 \| \| 1,500
3/0	0.064 \| \| 2,000
4/0	0.051 \| \| 2,500
250	0.043 \| \| 2,500
300	0.036 \| \| 2,500
350	0.031 \| \| 2,500
400	0.027 \| \| 2,500
450	0.024 \| \| 2,500
500	0.022 \| \| 2,500