Heads up: There are no amended sections in this chapter.

Table 1 Percent of Cross Section of Conduit and Tubing for Conductors and Cables

Number of Conductors and/or Cables Cross-Sectional Area (%)
1 53
2 31
Over 2 40

Informational Note No. 1: Table 1 is based on common conditions of proper cabling and alignment of conductors where the length of the pull and the number of bends are within reasonable limits. It should be recognized that, for certain conditions, a larger size conduit or a lesser conduit fill should be considered.

Informational Note No. 2: When pulling three conductors or cables into a raceway, if the ratio of the raceway (inside diameter) to the conductor or cable (outside diameter) is between 2.8 and 3.2, jamming can occur. While jamming can occur when pulling four or more conductors or cables into a raceway, the probability is very low.

Notes to Tables

  1. See Informative Annex C for the maximum number of conductors and fixture wires, all of the same size (total cross-sectional area including insulation) permitted in trade sizes of the applicable conduit or tubing.
  2. Table 1 applies only to complete conduit or tubing systems and is not intended to apply to sections of conduit or tubing used to protect exposed wiring and cables from physical damage.
  3. Equipment grounding or bonding conductors, where installed, shall be included when calculating conduit or tubing fill. The actual dimensions of the equipment grounding or bonding conductor (insulated or bare) shall be used in the calculation.
  4. Where conduit or tubing nipples having a maximum length not to exceed 600 mm (24 in.) are installed between boxes, cabinets, and similar enclosures, the nipples shall be permitted to be filled to 60 percent of their total cross-sectional area, and 310.15(C)(1) adjustment factors need not apply to this condition.
  5. For conductors not included in Chapter 9, such as multiconductor cables and optical fiber cables, the actual dimensions shall be used.
  6. For combinations of conductors of different sizes, use actual dimensions or Table 5 and Table 5A for dimensions of conductors and Table 4 for the applicable conduit or tubing dimensions.
  7. When calculating the maximum number of conductors or cables permitted in a conduit or tubing, all of the same size (total cross-sectional area including insulation), the next higher whole number shall be used to determine the maximum number of conductors permitted when the calculation results in a decimal greater than or equal to 0.8. When calculating the size for conduit or tubing permitted for a single conductor, one conductor shall be permitted when the calculation results in a decimal greater than or equal to 0.8.
  8. Where bare conductors are permitted by other sections of this Code, the dimensions for bare conductors in Table 8 shall be permitted.
  9. A multiconductor cable, optical fiber cable, or flexible cord of two or more conductors shall be treated as a single conductor for calculating percentage conduit or tubing fill area. For cables that have elliptical cross sections, the cross-sectional area calculation shall be based on using the major diameter of the ellipse as a circle diameter. Assemblies of single insulated conductors without an overall covering shall not be considered a cable when determining conduit or tubing fill area. The conduit or tubing fill for the assemblies shall be calculated based upon the individual conductors.
  10. The values for approximate conductor diameter and area shown in Table 5 are based on worst-case scenario and indicate round concentric-lay-stranded conductors. Solid and round concentric-lay-stranded conductor values are grouped together for the purpose of Table 5. Round compact-stranded conductor values are shown in Table 5A. If the actual values of the conductor diameter and area are known, they shall be permitted to be used.

Table 2 Radius of Conduit and Tubing Bends

Conduit or Tubing Size   One Shot and Full Shoe Benders   Other Bends
Metric Designator Trade Size   mm in.   mm in.
16 1/2   101.6 4   101.6 4
21 3/4   114.3 41/2   127 5
27 1   146.05 53/4   152.4 6
35 11/4   184.15 71/4   203.2 8
41 11/2   209.55 81/4   254 10
53 2   241.3 91/2   304.8 12
63 21/2   266.7 101/2   381 15
78 3   330.2 13   457.2 18
91 31/2   381 15   533.4 21
103 4   406.4 16   609.6 24
129 5   609.6 24   762 30
155 6   762 30   914.4 36

Table 4 Dimensions and Percent Area of Conduit and Tubing (Areas of Conduit or Tubing for the Combinations of Wires Permitted in Table 1, Chapter 9)

Article 358 — Electrical Metallic Tubing (EMT)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
16 1/2 78 0.122   118 0.182   104 0.161   61 0.094   15.8 0.622   196 0.304
21 3/4 137 0.213   206 0.320   182 0.283   106 0.165   20.9 0.824   343 0.533
27 1 222 0.346   333 0.519   295 0.458   172 0.268   26.6 1.049   556 0.864
35 11/4 387 0.598   581 0.897   513 0.793   300 0.464   35.1 1.380   968 1.496
41 11/2 526 0.814   788 1.221   696 1.079   407 0.631   40.9 1.610   1314 2.036
53 2 866 1.342   1299 2.013   1147 1.778   671 1.040   52.5 2.067   2165 3.356
63 21/2 1513 2.343   2270 3.515   2005 3.105   1173 1.816   69.4 2.731   3783 5.858
78 3 2280 3.538   3421 5.307   3022 4.688   1767 2.742   85.2 3.356   5701 8.846
91 31/2 2980 4.618   4471 6.927   3949 6.119   2310 3.579   97.4 3.834   7451 11.545
103 4 3808 5.901   5712 8.852   5046 7.819   2951 4.573   110.1 4.334   9521 14.753
 
Article 362 — Electrical Nonmetallic Tubing (ENT)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
16 1/2 73 0.114   110 0.171   97 0.151   57 0.088   15.3 0.602   184 0.285
21 3/4 131 0.203   197 0.305   174 0.269   102 0.157   20.4 0.804   328 0.508
27 1 215 0.333   322 0.499   284 0.441   166 0.258   26.1 1.029   537 0.832
35 11/4 375 0.581   562 0.872   497 0.770   291 0.450   34.5 1.36   937 1.453
41 11/2 512 0.794   769 1.191   679 1.052   397 0.616   40.4 1.59   1281 1.986
53 2 849 1.316   1274 1.975   1125 1.744   658 1.020   52 2.047   2123 3.291
63 21/2          
78 3          
91 31/2          
 
Article 348 — Flexible Metal Conduit (FMC)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8 30 0.046   44 0.069   39 0.061   23 0.036   9.7 0.384   74 0.116
16 1/2 81 0.127   122 0.190   108 0.168   63 0.098   16.1 0.635   204 0.317
21 3/4 137 0.213   206 0.320   182 0.283   106 0.165   20.9 0.824   343 0.533
27 1 211 0.327   316 0.490   279 0.433   163 0.253   25.9 1.020   527 0.817
35 11/4 330 0.511   495 0.766   437 0.677   256 0.396   32.4 1.275   824 1.277
41 11/2 480 0.743   720 1.115   636 0.985   372 0.576   39.1 1.538   1201 1.858
53 2 843 1.307   1264 1.961   1117 1.732   653 1.013   51.8 2.040   2107 3.269
63 21/2 1267 1.963   1900 2.945   1678 2.602   982 1.522   63.5 2.500   3167 4.909
78 3 1824 2.827   2736 4.241   2417 3.746   1414 2.191   76.2 3.000   4560 7.069
91 31/2 2483 3.848   3724 5.773   3290 5.099   1924 2.983   88.9 3.500   6207 9.621
103 4 3243 5.027   4864 7.540   4297 6.660   2513 3.896   101.6 4.000   8107 12.566
 
Article 342 — Intermediate Metal Conduit (IMC)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8          
16 1/2 89 0.137   133 0.205   117 0.181   69 0.106   16.8 0.660   222 0.342
21 3/4 151 0.235   226 0.352   200 0.311   117 0.182   21.9 0.864   377 0.586
27 1 248 0.384   372 0.575   329 0.508   192 0.297   28.1 1.105   620 0.959
35 11/4 425 0.659   638 0.988   564 0.873   330 0.510   36.8 1.448   1064 1.647
41 11/2 573 0.890   859 1.335   759 1.179   444 0.690   42.7 1.683   1432 2.225
53 2 937 1.452   1405 2.178   1241 1.924   726 1.125   54.6 2.150   2341 3.630
63 21/2 1323 2.054   1985 3.081   1753 2.722   1026 1.592   64.9 2.557   3308 5.135
78 3 2046 3.169   3069 4.753   2711 4.199   1586 2.456   80.7 3.176   5115 7.922
91 31/2 2729 4.234   4093 6.351   3616 5.610   2115 3.281   93.2 3.671   6822 10.584
103 4 3490 5.452   5235 8.179   4624 7.224   2705 4.226   105.4 4.166   8725 13.631
 
Article 356 — Liquidtight Flexible Nonmetallic Conduit (LFNC-A*)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8 50 0.077   75 0.115   66 0.102   39 0.060   12.6 0.495   125 0.192
16 1/2 80 0.125   121 0.187   107 0.165   62 0.097   16.0 0.630   201 0.312
21 3/4 139 0.214   208 0.321   184 0.283   107 0.166   21.0 0.825   346 0.535
27 1 221 0.342   331 0.513   292 0.453   171 0.265   26.5 1.043   552 0.854
35 11/4 387 0.601   581 0.901   513 0.796   300 0.466   35.1 1.383   968 1.502
41 11/2 520 0.807   781 1.211   690 1.070   403 0.626   40.7 1.603   1301 2.018
53 2 863 1.337   1294 2.006   1143 1.772   669 1.036   52.4 2.063   2157 3.343
*Corresponds to 356.2(1).
 
Article 356 — Liquidtight Flexible Nonmetallic Conduit (LFNC-B*)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8 49 0.077   74 0.115   65 0.102   38 0.059   12.5 0.494   123 0.192
16 1/2 81 0.125   122 0.188   108 0.166   63 0.097   16.1 0.632   204 0.314
21 3/4 140 0.216   210 0.325   185 0.287   108 0.168   21.1 0.830   350 0.541
27 1 226 0.349   338 0.524   299 0.462   175 0.270   26.8 1.054   564 0.873
35 11/4 394 0.611   591 0.917   522 0.810   305 0.474   35.4 1.395   984 1.528
41 11/2 510 0.792   765 1.188   676 1.050   395 0.614   40.3 1.588   1276 1.981
53 2 836 1.298   1255 1.948   1108 1.720   648 1.006   51.6 2.033   2091 3.246
*Corresponds to 356.2(2).
 
Article 356 — Liquidtight Flexible Nonmetallic Conduit (LFNC-C*)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8 47.7 0.074   71.5 0.111   63.2 0.098   36.9 0.057   12.3 0.485   119.19 0.185
16 1/2 77.9 0.121   116.9 0.181   103.2 0.160   60.4 0.094   15.7 0.620   194.778 0.302
21 3/4 134.6 0.209   201.9 0.313   178.4 0.276   104.3 0.162   20.7 0.815   336.568 0.522
27 1 215.0 0.333   322.5 0.500   284.9 0.442   166.6 0.258   26.2 1.030   537.566 0.833
35 11/4 380.4 0.590   570.6 0.884   504.1 0.781   294.8 0.457   34.8 1.370   951.039 1.474
41 1/2 509.2 0.789   763.8 1.184   674.7 1.046   394.6 0.612   40.3 1.585   1272.963 1.973
53 2 847.6 1.314   1271.4 1.971   1123.1 1.741   656.9 1.018   51.9 2.045   2119.063 3.285
*Corresponds to 356.2(3).
 
Article 350 — Liquidtight Flexible Metal Conduit (LFMC)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8 49 0.077   74 0.115   65 0.102   38 0.059   12.5 0.494   123 0.192
16 1/2 81 0.125   122 0.188   108 0.166   63 0.097   16.1 0.632   204 0.314
21 3/4 140 0.216   210 0.325   185 0.287   108 0.168   21.1 0.830   350 0.541
27 1 226 0.349   338 0.524   299 0.462   175 0.270   26.8 1.054   564 0.873
35 11/4 394 0.611   591 0.917   522 0.810   305 0.474   35.4 1.395   984 1.528
41 11/2 510 0.792   765 1.188   676 1.050   395 0.614   40.3 1.588   1276 1.981
53 2 836 1.298   1255 1.948   1108 1.720   648 1.006   51.6 2.033   2091 3.246
63 21/2 1259 1.953   1888 2.929   1668 2.587   976 1.513   63.3 2.493   3147 4.881
78 3 1931 2.990   2896 4.485   2559 3.962   1497 2.317   78.4 3.085   4827 7.475
91 31/2 2511 3.893   3766 5.839   3327 5.158   1946 3.017   89.4 3.520   6277 9.731
103 4 3275 5.077   4912 7.615   4339 6.727   2538 3.935   102.1 4.020   8187 12.692
129 5          
155 6          
 
Article 344 — Rigid Metal Conduit (RMC)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8          
16 1/2 81 0.125   122 0.188   108 0.166   63 0.097   16.1 0.632   204 0.314
21 3/4 141 0.220   212 0.329   187 0.291   109 0.170   21.2 0.836   353 0.549
27 1 229 0.355   344 0.532   303 0.470   177 0.275   27.0 1.063   573 0.887
35 11/4 394 0.610   591 0.916   522 0.809   305 0.473   35.4 1.394   984 1.526
41 11/2 533 0.829   800 1.243   707 1.098   413 0.642   41.2 1.624   1333 2.071
53 2 879 1.363   1319 2.045   1165 1.806   681 1.056   52.9 2.083   2198 3.408
63 21/2 1255 1.946   1882 2.919   1663 2.579   972 1.508   63.2 2.489   3137 4.866
78 3 1936 3.000   2904 4.499   2565 3.974   1500 2.325   78.5 3.090   4840 7.499
91 31/2 2584 4.004   3877 6.006   3424 5.305   2003 3.103   90.7 3.570   6461 10.010
103 4 3326 5.153   4990 7.729   4408 6.828   2578 3.994   102.9 4.050   8316 12.882
129 5 5220 8.085   7830 12.127   6916 10.713   4045 6.266   128.9 5.073   13050 20.212
155 6 7528 11.663   11292 17.495   9975 15.454   5834 9.039   154.8 6.093   18821 29.158
 
Article 352 — Rigid PVC Conduit (PVC), Schedule 80
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8          
16 1/2 56 0.087   85 0.130   75 0.115   44 0.067   13.4 0.526   141 0.217
21 3/4 105 0.164   158 0.246   139 0.217   82 0.127   18.3 0.722   263 0.409
27 1 178 0.275   267 0.413   236 0.365   138 0.213   23.8 0.936   445 0.688
35 11/4 320 0.495   480 0.742   424 0.656   248 0.383   31.9 1.255   799 1.237
41 11/2 442 0.684   663 1.027   585 0.907   342 0.530   37.5 1.476   1104 1.711
53 2 742 1.150   1113 1.725   983 1.523   575 0.891   48.6 1.913   1855 2.874
63 21/2 1064 1.647   1596 2.471   1410 2.183   825 1.277   58.2 2.290   2660 4.119
78 3 1660 2.577   2491 3.865   2200 3.414   1287 1.997   72.7 2.864   4151 6.442
91 31/2 2243 3.475   3365 5.213   2972 4.605   1738 2.693   84.5 3.326   5608 8.688
103 4 2907 4.503   4361 6.755   3852 5.967   2253 3.490   96.2 3.786   7268 11.258
129 5 4607 7.142   6911 10.713   6105 9.463   3571 5.535   121.1 4.768   11518 17.855
155 6 6605 10.239   9908 15.359   8752 13.567   5119 7.935   145.0 5.709   16513 25.598
 
Articles 352 and 353 — Rigid PVC Conduit (PVC), Schedule 40, and HDPE Conduit (HDPE)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
12 3/8          
16 1/2 74 0.114   110 0.171   97 0.151   57 0.088   15.3 0.602   184 0.285
21 3/4 131 0.203   196 0.305   173 0.269   101 0.157   20.4 0.804   327 0.508
27 1 214 0.333   321 0.499   284 0.441   166 0.258   26.1 1.029   535 0.832
35 11/4 374 0.581   561 0.872   495 0.770   290 0.450   34.5 1.360   935 1.453
41 11/2 513 0.794   769 1.191   679 1.052   397 0.616   40.4 1.590   1282 1.986
53 2 849 1.316   1274 1.975   1126 1.744   658 1.020   52.0 2.047   2124 3.291
63 21/2 1212 1.878   1817 2.817   1605 2.488   939 1.455   62.1 2.445   3029 4.695
78 3 1877 2.907   2816 4.361   2487 3.852   1455 2.253   77.3 3.042   4693 7.268
91 31/2 2511 3.895   3766 5.842   3327 5.161   1946 3.018   89.4 3.521   6277 9.737
103 4 3237 5.022   4855 7.532   4288 6.654   2508 3.892   101.5 3.998   8091 12.554
129 5 5099 7.904   7649 11.856   6756 10.473   3952 6.126   127.4 5.016   12748 19.761
155 6 7373 11.427   11060 17.140   9770 15.141   5714 8.856   153.2 6.031   18433 28.567
 
Article 352 — Type A, Rigid PVC Conduit (PVC)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
16 1/2 100 0.154   149 0.231   132 0.204   77 0.119   17.8 0.700   249 0.385
21 3/4 168 0.260   251 0.390   222 0.345   130 0.202   23.1 0.910   419 0.650
27 1 279 0.434   418 0.651   370 0.575   216 0.336   29.8 1.175   697 1.084
35 11/4 456 0.707   684 1.060   604 0.937   353 0.548   38.1 1.500   1140 1.767
41 11/2 600 0.929   900 1.394   795 1.231   465 0.720   43.7 1.720   1500 2.324
53 2 940 1.459   1410 2.188   1245 1.933   728 1.131   54.7 2.155   2350 3.647
63 21/2 1406 2.181   2109 3.272   1863 2.890   1090 1.690   66.9 2.635   3515 5.453
78 3 2112 3.278   3169 4.916   2799 4.343   1637 2.540   82.0 3.230   5281 8.194
91 31/2 2758 4.278   4137 6.416   3655 5.668   2138 3.315   93.7 3.690   6896 10.694
103 4 3543 5.489   5315 8.234   4695 7.273   2746 4.254   106.2 4.180   8858 13.723
129 5          
155 6          
 
Article 352 — Type EB, Rigid PVC Conduit (PVC)
Metric Designator Trade Size Over 2 Wires 40%   60%   1 Wire 53%   2 Wires 31%   Nominal Internal Diameter   Total Area 100%
mm2 in.2   mm2 in.2   mm2 in.2   mm2 in.2   mm in.   mm2 in.2
16 1/2          
21 3/4          
27 1          
35 11/4          
41 11/2          
53 2 999 1.550   1499 2.325   1324 2.053   774 1.201   56.4 2.221   2498 3.874
63 21/2          
78 3 2248 3.484   3373 5.226   2979 4.616   1743 2.700   84.6 3.330   5621 8.709
91 31/2 2932 4.546   4397 6.819   3884 6.023   2272 3.523   96.6 3.804   7329 11.365
103 4 3726 5.779   5589 8.669   4937 7.657   2887 4.479   108.9 4.289   9314 14.448
129 5 5726 8.878   8588 13.317   7586 11.763   4437 6.881   135.0 5.316   14314 22.195
155 6 8133 12.612   12200 18.918   10776 16.711   6303 9.774   160.9 6.336   20333 31.530

Table 5 Dimensions of Insulated Conductors and Fixture Wires

Type Size (AWG or kcmil) Approximate Area   Approximate Diameter
mm2 in.2   mm in.
Type: FFH-2, RFH-1, RFH-2, RFHH-2, RHH*, RHW*, RHW-2*, RHH, RHW, RHW-2, SF-1, SF-2, SFF-1, SFF-2, TF, TFF, THHW, THW, THW-2, TW, XF, XFF
RFH-2, FFH-2, RFHH-2 18 9.355 0.0145   3.454 0.136
16 11.10 0.0172   3.759 0.148
RHH, RHW, RHW-2 14 18.90 0.0293   4.902 0.193
12 22.77 0.0353   5.385 0.212
10 28.19 0.0437   5.994 0.236
8 53.87 0.0835   8.280 0.326
6 67.16 0.1041   9.246 0.364
4 86.00 0.1333   10.46 0.412
3 98.13 0.1521   11.18 0.440
2 112.9 0.1750   11.99 0.472
1 171.6 0.2660   14.78 0.582
1/0 196.1 0.3039   15.80 0.622
2/0 226.1 0.3505   16.97 0.668
3/0 262.7 0.4072   18.29 0.720
4/0 306.7 0.4754   19.76 0.778
250 405.9 0.6291   22.73 0.895
300 457.3 0.7088   24.13 0.950
350 507.7 0.7870   25.43 1.001
400 556.5 0.8626   26.62 1.048
500 650.5 1.0082   28.78 1.133
600 782.9 1.2135   31.57 1.243
700 874.9 1.3561   33.38 1.314
750 920.8 1.4272   34.24 1.348
800 965.0 1.4957   35.05 1.380
900 1057 1.6377   36.68 1.444
1000 1143 1.7719   38.15 1.502
1250 1515 2.3479   43.92 1.729
1500 1738 2.6938   47.04 1.852
1750 1959 3.0357   49.94 1.966
2000 2175 3.3719   52.63 2.072
SF-2, SFF-2 18 7.419 0.0115   3.073 0.121
16 8.968 0.0139   3.378 0.133
14 11.10 0.0172   3.759 0.148
SF-1, SFF-1 18 4.194 0.0065   2.311 0.091
RFH-1,TF, TFF, XF, XFF 18 5.161 0.0088   2.692 0.106
TF, TFF, XF, XFF 16 7.032 0.0109   2.997 0.118
TW, XF, XFF, THHW, THW, THW-2 14 8.968 0.0139   3.378 0.133
TW, THHW, THW, THW-2 12 11.68 0.0181   3.861 0.152
10 15.68 0.0243   4.470 0.176
8 28.19 0.0437   5.994 0.236
RHH*, RHW*, RHW-2* 14 13.48 0.0209   4.140 0.163
RHH*, RHW*, RHW-2*, XF, XFF 12 16.77 0.0260   4.623 0.182
Type: RHH*, RHW*, RHW-2*, THHN, THHW, THW, THW-2, TFN, TFFN, THWN, THWN-2, XF, XFF
RHH,* RHW,* RHW-2,* XF, XFF 10 21.48 0.0333   5.232 0.206
RHH*, RHW*, RHW-2* 8 35.87 0.0556   6.756 0.266
TW, THW, THHW, THW-2, RHH*, RHW*, RHW-2* 6 46.84 0.0726   7.722 0.304
4 62.77 0.0973   8.941 0.352
3 73.16 0.1134   9.652 0.380
2 86.00 0.1333   10.46 0.412
1 122.6 0.1901   12.50 0.492
1/0 143.4 0.2223   13.51 0.532
2/0 169.3 0.2624   14.68 0.578
3/0 201.1 0.3117   16.00 0.630
4/0 239.9 0.3718   17.48 0.688
250 296.5 0.4596   19.43 0.765
300 340.7 0.5281   20.83 0.820
350 384.4 0.5958   22.12 0.871
400 427.0 0.6619   23.32 0.918
500 509.7 0.7901   25.48 1.003
600 627.7 0.9729   28.27 1.113
700 710.3 1.1010   30.07 1.184
750 751.7 1.1652   30.94 1.218
800 791.7 1.2272   31.75 1.250
900 874.9 1.3561   33.38 1.314
1000 953.8 1.4784   34.85 1.372
1250 1200 1.8602   39.09 1.539
1500 1400 2.1695   42.21 1.662
1750 1598 2.4773   45.11 1.776
2000 1795 2.7818   47.80 1.882
TFN, TFFN 18 3.548 0.0055   2.134 0.084
16 4.645 0.0072   2.438 0.096
THHN, THWN, THWN-2 14 6.258 0.0097   2.819 0.111
12 8.581 0.0133   3.302 0.130
10 13.61 0.0211   4.166 0.164
8 23.61 0.0366   5.486 0.216
6 32.71 0.0507   6.452 0.254
4 53.16 0.0824   8.230 0.324
3 62.77 0.0973   8.941 0.352
2 74.71 0.1158   9.754 0.384
1 100.8 0.1562   11.33 0.446
1/0 119.7 0.1855   12.34 0.486
2/0 143.4 0.2223   13.51 0.532
3/0 172.8 0.2679   14.83 0.584
4/0 208.8 0.3237   16.31 0.642
250 256.1 0.3970   18.06 0.711
300 297.3 0.4608   19.46 0.766
Type: FEP, FEPB, PAF, PAFF, PF, PFA, PFAH, PFF, PGF, PGFF, PTF, PTFF, TFE, THHN, THWN, THWN-2, Z, ZF, ZFF, ZHF
THHN, THWN, THWN-2 350 338.2 0.5242   20.75 0.817
400 378.3 0.5863   21.95 0.864
500 456.3 0.7073   24.10 0.949
600 559.7 0.8676   26.70 1.051
700 637.9 0.9887   28.50 1.122
750 677.2 1.0496   29.36 1.156
800 715.2 1.1085   30.18 1.188
900 794.3 1.2311   31.80 1.252
1000 869.5 1.3478   33.27 1.310
PF, PGFF, PGF, PFF, PTF, PAF, PTFF, PAFF 18 3.742 0.0058   2.184 0.086
16 4.839 0.0075   2.489 0.098
PF, PGFF, PGF, PFF, PTF, PAF, PTFF, PAFF, TFE, FEP, PFA, FEPB, PFAH 14 6.452 0.0100   2.870 0.113
TFE, FEP, PFA, FEPB, PFAH 12 8.839 0.0137   3.353 0.132
10 12.32 0.0191   3.962 0.156
8 21.48 0.0333   5.232 0.206
6 30.19 0.0468   6.198 0.244
4 43.23 0.0670   7.417 0.292
3 51.87 0.0804   8.128 0.320
2 62.77 0.0973   8.941 0.352
TFE, PFAH, PFA 1 90.26 0.1399   10.72 0.422
TFE, PFA, PFAH, Z 1/0 108.1 0.1676   11.73 0.462
2/0 130.8 0.2027   12.90 0.508
3/0 158.9 0.2463   14.22 0.560
4/0 193.5 0.3000   15.70 0.618
ZF, ZFF, ZHF 18 2.903 0.0045   1.930 0.076
16 3.935 0.0061   2.235 0.088
Z, ZF, ZFF, ZHF 14 5.355 0.0083   2.616 0.103
Z 12 7.548 0.0117   3.099 0.122
10 12.32 0.0191   3.962 0.156
8 19.48 0.0302   4.978 0.196
6 27.74 0.0430   5.944 0.234
4 40.32 0.0625   7.163 0.282
3 55.16 0.0855   8.382 0.330
2 66.39 0.1029   9.195 0.362
1 81.87 0.1269   10.21 0.402
Type: KF-1, KF-2, KFF-1, KFF-2, XHH, XHHW, XHHW-2, ZW
XHHW, ZW, XHHW-2, XHH 14 8.968 0.0139   3.378 0.133
12 11.68 0.0181   3.861 0.152
10 15.68 0.0243   4.470 0.176
8 28.19 0.0437   5.994 0.236
6 38.06 0.0590   6.960 0.274
4 52.52 0.0814   8.179 0.322
3 62.06 0.0962   8.890 0.350
2 73.94 0.1146   9.703 0.382
XHHW, XHHW-2, XHH 1 98.97 0.1534   11.23 0.442
1/0 117.7 0.1825   12.24 0.482
2/0 141.3 0.2190   13.41 0.528
3/0 170.5 0.2642   14.73 0.58
4/0 206.3 0.3197   16.21 0.638
250 251.9 0.3904   17.91 0.705
300 292.6 0.4536   19.30 0.76
350 333.3 0.5166   20.60 0.811
400 373.0 0.5782   21.79 0.858
500 450.6 0.6984   23.95 0.943
600 561.9 0.8709   26.75 1.053
700 640.2 0.9923   28.55 1.124
750 679.5 1.0532   29.41 1.158
800 717.5 1.1122   30.23 1.190
900 796.8 1.2351   31.85 1.254
1000 872.2 1.3519   33.32 1.312
1250 1108 1.7180   37.57 1.479
1500 1300 2.0156   40.69 1.602
1750 1492 2.3127   43.59 1.716
2000 1682 2.6073   46.28 1.822
KF-2, KFF-2 18 2.000 0.003   1.575 0.062
16 2.839 0.0043   1.88 0.074
14 4.129 0.0064   2.286 0.090
12 6.000 0.0092   2.743 0.108
10 8.968 0.0139   3.378 0.133
KF-1, KFF-1 18 1.677 0.0026   1.448 0.057
16 2.387 0.0037   1.753 0.069
14 3.548 0.0055   2.134 0.084
12 5.355 0.0083   2.616 0.103
10 8.194 0.0127   3.226 0.127
*Types RHH, RHW, and RHW-2 without outer covering.

Table 5A Compact Copper and Aluminum Building Wire Nominal Dimensions** and Areas

Size (AWG or kcmil) Bare Conductor Types RHH* Types THW and THHW Type THHN Type XHHW Size (AWG or kcmil)
Diameter Approximate Diameter Approximate Area Approximate Diameter Approximate Area Approximate Diameter Approximate Area Approximate Diameter Approximate Area
mm in. mm in. mm2 in.2 mm in. mm2 in.2 mm in. mm2 in.2 mm in. mm2 in.2
8 3.404 0.134 6.604 0.260 34.25 0.0531 6.477 0.255 32.90 0.0510 5.690 0.224 25.42 0.0394 8
6 4.293 0.169 7.493 0.295 44.10 0.0683 7.366 0.290 42.58 0.0660 6.096 0.240 29.16 0.0452 6.604 0.260 34.19 0.0530 6
4 5.410 0.213 8.509 0.335 56.84 0.0881 8.509 0.335 56.84 0.0881 7.747 0.305 47.10 0.0730 7.747 0.305 47.10 0.0730 4
2 6.807 0.268 9.906 0.390 77.03 0.1194 9.906 0.390 77.03 0.1194 9.144 0.360 65.61 0.1017 9.144 0.360 65.61 0.1017 2
1 7.595 0.299 11.81 0.465 109.5 0.1698 11.81 0.465 109.5 0.1698 10.54 0.415 87.23 0.1352 10.54 0.415 87.23 0.1352 1
1/0 8.534 0.336 12.70 0.500 126.6 0.1963 12.70 0.500 126.6 0.1963 11.43 0.450 102.6 0.1590 11.43 0.450 102.6 0.1590 1/0
2/0 9.550 0.376 13.72 0.540 147.8 0.2290 13.84 0.545 150.5 0.2332 12.57 0.495 124.1 0.1924 12.45 0.490 121.6 0.1885 2/0
3/0 10.74 0.423 14.99 0.590 176.3 0.2733 14.99 0.590 176.3 0.2733 13.72 0.540 147.7 0.2290 13.72 0.540 147.7 0.2290 3/0
4/0 12.07 0.475 16.26 0.640 207.6 0.3217 16.38 0.645 210.8 0.3267 15.11 0.595 179.4 0.2780 14.99 0.590 176.3 0.2733 4/0
250 13.21 0.520 18.16 0.715 259.0 0.4015 18.42 0.725 266.3 0.4128 17.02 0.670 227.4 0.3525 16.76 0.660 220.7 0.3421 250
300 14.48 0.570 19.43 0.765 296.5 0.4596 19.69 0.775 304.3 0.4717 18.29 0.720 262.6 0.4071 18.16 0.715 259.0 0.4015 300
350 15.65 0.616 20.57 0.810 332.3 0.5153 20.83 0.820 340.7 0.5281 19.56 0.770 300.4 0.4656 19.30 0.760 292.6 0.4536 350
400 16.74 0.659 21.72 0.855 370.5 0.5741 21.97 0.865 379.1 0.5876 20.70 0.815 336.5 0.5216 20.32 0.800 324.3 0.5026 400
500 18.69 0.736 23.62 0.930 438.2 0.6793 23.88 0.940 447.7 0.6939 22.48 0.885 396.8 0.6151 22.35 0.880 392.4 0.6082 500
600 20.65 0.813 26.29 1.035 542.8 0.8413 26.67 1.050 558.6 0.8659 25.02 0.985 491.6 0.7620 24.89 0.980 486.6 0.7542 600
700 22.28 0.877 27.94 1.100 613.1 0.9503 28.19 1.110 624.3 0.9676 26.67 1.050 558.6 0.8659 26.67 1.050 558.6 0.8659 700
750 23.06 0.908 28.83 1.135 652.8 1.0118 29.21 1.150 670.1 1.0386 27.31 1.075 585.5 0.9076 27.69 1.090 602.0 0.9331 750
900 25.37 0.999 31.50 1.240 779.3 1.2076 31.09 1.224 759.1 1.1766 30.33 1.194 722.5 1.1196 29.69 1.169 692.3 1.0733 900
1000 26.92 1.060 32.64 1.285 836.6 1.2968 32.64 1.285 836.6 1.2968 31.88 1.255 798.1 1.2370 31.24 1.230 766.6 1.1882 1000
*Types RHH and RHW without outer coverings.
**Dimensions are from industry sources.

Table 8 Conductor Properties

Size (AWG or kcmil) Area Conductors Direct-Current Resistance at 75°C (167°F)
Stranding Overall Copper  
  Diameter Diameter Area Uncoated Coated Aluminum
mm2 Circular mils Quantity mm in. mm in. mm2 in.2 ohm/km ohm/kFT ohm/km ohm/kFT ohm/km ohm/kFT
18 0.823 1620 1 1.02 0.040 0.823 0.001 25.5 7.77 26.5 8.08 42.0 12.8
18 0.823 1620 7 0.39 0.015 1.16 0.046 1.06 0.002 26.1 7.95 27.7 8.45 42.8 13.1
16 1.31 2580 1 1.29 0.051 1.31 0.002 16.0 4.89 16.7 5.08 26.4 8.05
16 1.31 2580 7 0.49 0.019 1.46 0.058 1.68 0.003 16.4 4.99 17.3 5.29 26.9 8.21
14 2.08 4110 1 1.63 0.064 2.08 0.003 10.1 3.07 10.4 3.19 16.6 5.06
14 2.08 4110 7 0.62 0.024 1.85 0.073 2.68 0.004 10.3 3.14 10.7 3.26 16.9 5.17
12 3.31 6530 1 2.05 0.081 3.31 0.005 6.34 1.93 6.57 2.01 10.45 3.18
12 3.31 6530 7 0.78 0.030 2.32 0.092 4.25 0.006 6.50 1.98 6.73 2.05 10.69 3.25
10 5.261 10380 1 2.588 0.102 5.26 0.008 3.984 1.21 4.148 1.26 6.561 2.00
10 5.261 10380 7 0.98 0.038 2.95 0.116 6.76 0.011 4.070 1.24 4.226 1.29 6.679 2.04
8 8.367 16510 1 3.264 0.128 8.37 0.013 2.506 0.764 2.579 0.786 4.125 1.26
8 8.367 16510 7 1.23 0.049 3.71 0.146 10.76 0.017 2.551 0.778 2.653 0.809 4.204 1.28
6 13.30 26240 7 1.56 0.061 4.67 0.184 17.09 0.027 1.608 0.491 1.671 0.510 2.652 0.808
4 21.15 41740 7 1.96 0.077 5.89 0.232 27.19 0.042 1.010 0.308 1.053 0.321 1.666 0.508
3 26.67 52620 7 2.20 0.087 6.60 0.260 34.28 0.053 0.802 0.245 0.833 0.254 1.320 0.403
2 33.62 66360 7 2.47 0.097 7.42 0.292 43.23 0.067 0.634 0.194 0.661 0.201 1.045 0.319
1 42.41 83690 19 1.69 0.066 8.43 0.332 55.80 0.087 0.505 0.154 0.524 0.160 0.829 0.253

1/0

53.49 105600 19 1.89 0.074 9.45 0.372 70.41 0.109 0.399 0.122 0.415 0.127 0.660 0.201

2/0

67.43 133100 19 2.13 0.084 10.62 0.418 88.74 0.137 0.3170 0.0967 0.329 0.101 0.523 0.159

3/0

85.01 167800 19 2.39 0.094 11.94 0.470 111.9 0.173 0.2512 0.0766 0.2610 0.0797 0.413 0.126

4/0

107.2 211600 19 2.68 0.106 13.41 0.528 141.1 0.219 0.1996 0.0608 0.2050 0.0626 0.328 0.100
250 127 37 2.09 0.082 14.61 0.575 168 0.260 0.1687 0.0515 0.1753 0.0535 0.2778 0.0847
300 152 37 2.29 0.090 16.00 0.630 201 0.312 0.1409 0.0429 0.1463 0.0446 0.2318 0.0707
350 177 37 2.47 0.097 17.30 0.681 235 0.364 0.1205 0.0367 0.1252 0.0382 0.1984 0.0605
400 203 37 2.64 0.104 18.49 0.728 268 0.416 0.1053 0.0321 0.1084 0.0331 0.1737 0.0529
500 253 37 2.95 0.116 20.65 0.813 336 0.519 0.0845 0.0258 0.0869 0.0265 0.1391 0.0424
600 304 61 2.52 0.099 22.68 0.893 404 0.626 0.0704 0.0214 0.0732 0.0223 0.1159 0.0353
700 355 61 2.72 0.107 24.49 0.964 471 0.730 0.0603 0.0184 0.0622 0.0189 0.0994 0.0303
750 380 61 2.82 0.111 25.35 0.998 505 0.782 0.0563 0.0171 0.0579 0.0176 0.0927 0.0282
800 405 61 2.91 0.114 26.16 1.030 538 0.834 0.0528 0.0161 0.0544 0.0166 0.0868 0.0265
900 456 61 3.09 0.122 27.79 1.094 606 0.940 0.0470 0.0143 0.0481 0.0147 0.0770 0.0235
1000 507 61 3.25 0.128 29.26 1.152 673 1.042 0.0423 0.0129 0.0434 0.0132 0.0695 0.0212
1250 633 91 2.98 0.117 32.74 1.289 842 1.305 0.0338 0.0103 0.0347 0.0106 0.0554 0.0169
1500 760 91 3.26 0.128 35.86 1.412 1011 1.566 0.02814 0.00858 0.02814 0.00883 0.0464 0.0141
1750 887 127 2.98 0.117 38.76 1.526 1180 1.829 0.02410 0.00735 0.02410 0.00756 0.0397 0.0121
2000 1013 127 3.19 0.126 41.45 1.632 1349 2.092 0.02109 0.00643 0.02109 0.00662 0.0348 0.0106
Notes:
1. These resistance values are valid only for the parameters as given. Using conductors having coated strands, different stranding type, and, especially, other temperatures changes the resistance.
2. Equation for temperature change: R2 = R1 [1 + a (T2—75)], where αcu = 0.00323, αAL = 0.00330 at 75°C.
3. Conductors with compact and compressed stranding have about 9 percent and 3 percent, respectively, smaller bare conductor diameters than those shown. See Table 5A for actual compact cable dimensions.
4. The IACS conductivities used: bare copper = 100%, aluminum = 61%.
5. Class B stranding is listed as well as solid for some sizes. Its overall diameter and area are those of its circumscribing circle.
Informational Note: The construction information is in accordance with NEMA WC/70-2009 or ANSI/UL 1581-2017.
The resistance is calculated in accordance with National Bureau of Standards Handbook 100, dated 1966, and Handbook 109, dated 1972.

Table 9 Alternating-Current Resistance and Reactance for 600-Volt Cables, 3-Phase, 60 Hz, 75°C (167°F) — Three Single Conductors in Conduit

Size (AWG or kcmil) Ohms to Neutral per Kilometer
Ohms to Neutral per 1000 Feet
Size (AWG or kcmil)
XL (Reactance) for All Wires Alternating-Current Resistance for Uncoated Copper Wires Alternating-Current Resistance for Aluminum Wires Effective Z at 0.85 PF for Uncoated Copper Wires Effective Z at 0.85 PF for Aluminum Wires
PVC, Aluminum Conduits Steel Conduit PVC Conduit Aluminum Conduit Steel Conduit PVC Conduit Aluminum Conduit Steel Conduit PVC Conduit Aluminum Conduit Steel Conduit PVC Conduit Aluminum Conduit Steel Conduit
14 0.190 0.240 10.2 10.2 10.2 8.9 8.9 8.9 14
0.058 0.073 3.1 3.1 3.1 2.7 2.7 2.7
12 0.177 0.223 6.6 6.6 6.6 10.5 10.5 10.5 5.6 5.6 5.6 9.2 9.2 9.2 12
0.054 0.068 2.0 2.0 2.0 3.2 3.2 3.2 1.7 1.7 1.7 2.8 2.8 2.8
10 0.164 0.207 3.9 3.9 3.9 6.6 6.6 6.6 3.6 3.6 3.6 5.9 5.9 5.9 10
0.050 0.063 1.2 1.2 1.2 2.0 2.0 2.0 1.1 1.1 1.1 1.8 1.8 1.8
8 0.171 0.213 2.56 2.56 2.56 4.3 4.3 4.3 2.26 2.26 2.30 3.6 3.6 3.6 8
0.052 0.065 0.78 0.78 0.78 1.3 1.3 1.3 0.69 0.69 0.70 1.1 1.1 1.1
6 0.167 0.210 1.61 1.61 1.61 2.66 2.66 2.66 1.44 1.48 1.48 2.33 2.36 2.36 6
0.051 0.064 0.49 0.49 0.49 0.81 0.81 0.81 0.44 0.45 0.45 0.71 0.72 0.72
4 0.157 0.197 1.02 1.02 1.02 1.67 1.67 1.67 0.95 0.95 0.98 1.51 1.51 1.51 4
0.048 0.060 0.31 0.31 0.31 0.51 0.51 0.51 0.29 0.29 0.30 0.46 0.46 0.46
3 0.154 0.194 0.82 0.82 0.82 1.31 1.35 1.31 0.75 0.79 0.79 1.21 1.21 1.21 3
0.047 0.059 0.25 0.25 0.25 0.40 0.41 0.40 0.23 0.24 0.24 0.37 0.37 0.37
2 0.148 0.187 0.62 0.66 0.66 1.05 1.05 1.05 0.62 0.62 0.66 0.98 0.98 0.98 2
0.045 0.057 0.19 0.20 0.20 0.32 0.32 0.32 0.19 0.19 0.20 0.30 0.30 0.30
1 0.151 0.187 0.49 0.52 0.52 0.82 0.85 0.82 0.52 0.52 0.52 0.79 0.79 0.82 1
0.046 0.057 0.15 0.16 0.16 0.25 0.26 0.25 0.16 0.16 0.16 0.24 0.24 0.25
1/0 0.144 0.180 0.39 0.43 0.39 0.66 0.69 0.66 0.43 0.43 0.43 0.62 0.66 0.66 1/0
0.044 0.055 0.12 0.13 0.12 0.20 0.21 0.20 0.13 0.13 0.13 0.19 0.20 0.20
2/0 0.141 0.177 0.33 0.33 0.33 0.52 0.52 0.52 0.36 0.36 0.36 0.52 0.52 0.52 2/0
0.043 0.054 0.10 0.10 0.10 0.16 0.16 0.16 0.11 0.11 0.11 0.16 0.16 0.16
3/0 0.138 0.171 0.253 0.269 0.259 0.43 0.43 0.43 0.289 0.302 0.308 0.43 0.43 0.46 3/0
0.042 0.052 0.077 0.082 0.079 0.13 0.13 0.13 0.088 0.092 0.094 0.13 0.13 0.14
4/0 0.135 0.167 0.203 0.220 0.207 0.33 0.36 0.33 0.243 0.256 0.262 0.36 0.36 0.36 4/0
0.041 0.051 0.062 0.067 0.063 0.10 0.11 0.10 0.074 0.078 0.080 0.11 0.11 0.11
250 0.135 0.171 0.171 0.187 0.177 0.279 0.295 0.282 0.217 0.230 0.240 0.308 0.322 0.33 250
0.041 0.052 0.052 0.057 0.054 0.085 0.090 0.086 0.066 0.070 0.073 0.094 0.098 0.10
300 0.135 0.167 0.144 0.161 0.148 0.233 0.249 0.236 0.194 0.207 0.213 0.269 0.282 0.289 300
0.041 0.051 0.044 0.049 0.045 0.071 0.076 0.072 0.059 0.063 0.065 0.082 0.086 0.088
350 0.131 0.164 0.125 0.141 0.128 0.200 0.217 0.207 0.174 0.190 0.197 0.240 0.253 0.262 350
0.040 0.050 0.038 0.043 0.039 0.061 0.066 0.063 0.053 0.058 0.060 0.073 0.077 0.080
400 0.131 0.161 0.108 0.125 0.115 0.177 0.194 0.180 0.161 0.174 0.184 0.217 0.233 0.240 400
0.040 0.049 0.033 0.038 0.035 0.054 0.059 0.055 0.049 0.053 0.056 0.066 0.071 0.073
500 0.128 0.157 0.089 0.105 0.095 0.141 0.157 0.148 0.141 0.157 0.164 0.187 0.200 0.210 500
0.039 0.048 0.027 0.032 0.029 0.043 0.048 0.045 0.043 0.048 0.050 0.057 0.061 0.064
600 0.128 0.157 0.075 0.092 0.082 0.118 0.135 0.125 0.131 0.144 0.154 0.167 0.180 0.190 600
0.039 0.048 0.023 0.028 0.025 0.036 0.041 0.038 0.040 0.044 0.047 0.051 0.055 0.058
750 0.125 0.157 0.062 0.079 0.069 0.095 0.112 0.102 0.118 0.131 0.141 0.148 0.161 0.171 750
0.038 0.048 0.019 0.024 0.021 0.029 0.034 0.031 0.036 0.040 0.043 0.045 0.049 0.052
1000 0.121 0.151 0.049 0.062 0.059 0.075 0.089 0.082 0.105 0.118 0.131 0.128 0.138 0.151 1000
0.037 0.046 0.015 0.019 0.018 0.023 0.027 0.025 0.032 0.036 0.040 0.039 0.042 0.046
Notes:
1. These values are based on the following constants: UL-Type RHH wires with Class B stranding, in cradled configuration. Wire conductivities are 100 percent IACS copper and 61 percent IACS aluminum, and aluminum conduit is 45 percent IACS. Capacitive reactance is ignored, since it is negligible at these voltages. These resistance values are valid only at 75°C (167°F) and for the parameters as given, but are representative for 600-volt wire types operating at 60 Hz.
2. Effective Z is defined as R cos(θ) + X sin(θ), where θ is the power factor angle of the circuit. Multiplying current by effective impedance gives a good approximation for line-to-neutral voltage drop. Effective impedance values shown in this table are valid only at 0.85 power factor. For another circuit power factor (PF), effective impedance (Ze) can be calculated from R and XL values given in this table as follows: Ze = R × PF + XLsin[arccos(PF)].

Table 10 Conductor Stranding

Conductor Size Number of Strands
Copper Aluminum
AWG or kcmil mm2 Class Ba Class C Class Ba
24—30 0.20—0.05 b
22 0.32 7
20 0.52 10
18 0.82 16
16 1.3 26
14—2 2.1—33.6 7 19 7c
1—4/0 42.4—107 19 37 19
250—500 127—253 37 61 37
600—1000 304—508 61 91 61
1250—1500 635—759 91 127 91
1750—2000 886—1016 127 271 127
aConductors with a lesser number of strands shall be permitted based on an evaluation for connectability and bending.
bNumber of strands vary.
cAluminum 14 AWG (2.1 mm2) is not available.
With the permission of Underwriters Laboratories, Inc., material is reproduced from UL Standard 486A-B, Wire Connectors, which is copyrighted by Underwriters Laboratories, Inc., Northbrook, Illinois. While use of this material has been authorized, UL shall not be responsible for the manner in which the information is presented, nor for any interpretations thereof. For more information on UL or to purchase standards, please visit our Standards website at www.comm-2000.com or call 1-888-853-3503.

Table 11(A) and Table 11(B)

For listing purposes, Table 11(A) and Table 11(B) provide the required power source limitations for Class 2 and Class 3 power sources. Table 11 (A) applies for alternating-current sources, and Table 11(B) applies for direct-current sources.

The power for Class 2 and Class 3 circuits shall be either (1) inherently limited, requiring no overcurrent protection, or (2) not inherently limited, requiring a combination of power source and overcurrent protection. Power sources designed for interconnection shall be listed for the purpose.

As part of the listing, the Class 2 or Class 3 power source shall be durably marked where plainly visible to indicate the class of supply and its electrical rating. A Class 2 power source not suitable for wet location use shall be so marked.

Exception: Limited power circuits used by listed information technology equipment.

Overcurrent devices, where required, shall be located at the point where the conductor to be protected receives its supply and shall not be interchangeable with devices of higher ratings. The overcurrent device shall be permitted as an integral part of the power source.

Table 11(A) Class 2 and Class 3 Alternating-Current Power Source Limitations

Power Source Inherently Limited Power Source (Overcurrent Protection Not Required) Not Inherently Limited Power Source (Overcurrent Protection Required)
Class 2 Class 3 Class 2 Class 3
Source voltage Vmax (volts)(see Note 1) 0 through 20* Over 20 and through 30* Over 30 and through 150 Over 30 and through 100 0 through 20* Over 20 and through 30* Over 30 and through 100 Over 100 and through 150
Power limitations VAmax (volt-amperes)(see Note 1) 250 (see Note 3) 250 250 N.A.
Current limitations Imax (amperes)(see Note 1) 8.0 8.0 0.005 150/Vmax 1000/Vmax 1000/Vmax 1000/Vmax 1.0
Maximum overcurrent protection (amperes) 5.0 100/Vmax 100/Vmax 1.0
Power source maximum nameplate rating VA (volt-amperes) 5.0 × Vmax 100 0.005 × Vmax 100 5.0 × Vmax 100 100 100
Current (amperes) 5.0 100/Vmax 0.005 100/Vmax 5.0 100/Vmax 100/Vmax 100/Vmax
Note: Notes for this table can be found following Table 11(B).
*Voltage ranges shown are for sinusoidal ac in indoor locations or where wet contact is not likely to occur.
For nonsinusoidal or wet contact conditions, see Note 2.

Table 11(B) Class 2 and Class 3 Direct-Current Power Source Limitations

Power Source Inherently Limited Power Source (Overcurrent Protection Not Required) Not Inherently Limited Power Source (Overcurrent Protection Required)
Class 2 Class 3 Class 2 Class 3
Source voltage Vmax (volts)(see Note 1) 0 through 20* Over 20 and through 30* Over 30 and through 60* Over 60 and through 150 Over 60 and through 100 0 through 20* Over 20 and through 60* Over 60 and through 100 Over 100 and through 150
Power limitations VA max (volt-amperes)(see Note 1) 250 (see Note 3) 250 250 N.A.
Current limitations Imax (amperes)(see Note 1) 8.0 8.0 150/Vmax 0.005 150/Vmax 1000/Vmax 1000/Vmax 1000/Vmax 1.0
Maximum overcurrent protection (amperes) 5.0 100/Vmax 100/Vmax 1.0
Power source maximum nameplate rating VA (volt-amperes) 5.0 × Vmax 100 100 0.005 × Vmax 100 5.0 × Vmax 100 100 100
Current (amperes) 5.0 100/Vmax 100/Vmax 0.005 100/Vmax 5.0 100/Vmax 100/Vmax 100/Vmax
*Voltage ranges shown are for continuous dc in indoor locations or where wet contact is not likely to occur.
For interrupted dc or wet contact conditions, see Note 4.
Notes for Table 11(A) and Table 11(B)
1. Vmax, Imax, and VAmax are determined with the current-limiting impedance in the circuit (not bypassed) as follows:
Vmax:Maximum output voltage regardless of load with rated input applied.
Imax: Maximum output current under any noncapacitive load, including short circuit, and with overcurrent protection bypassed if used. Where a transformer limits the output current, Imax limits apply after 1 minute of operation. Where a current-limiting impedance, listed for the purpose, or as part of a listed product, is used in combination with a non-power-limited transformer or a stored energy source, e.g., storage battery, to limit the output current, Imax limits apply after 5 seconds.
VAmax: Maximum volt-ampere output after 1 minute of operation regardless of load and overcurrent protection bypassed if used.
2. For nonsinusoidal ac, Vmax shall not be greater than 42.4 volts peak. Where wet contact (immersion not included) is likely to occur, Class 3 wiring methods shall be used or Vmax shall not be greater than 15 volts for sinusoidal ac and 21.2 volts peak for nonsinusoidal ac.
3. If the power source is a transformer, VAmax is 350 or less when Vmax is 15 or less.
4. For dc interrupted at a rate of 10 to 200 Hz, Vmax shall not be greater than 24.8 volts peak. Where wet contact (immersion not included) is likely to occur, Class 3 wiring methods shall be used, or Vmax shall not be greater than 30 volts for continuous dc; 12.4 volts peak for dc that is interrupted at a rate of 10 to 200 Hz.

Table 12(A) and Table 12(B)

For listing purposes, Table 12(A) and Table 12(B) provide the required power source limitations for power-limited fire alarm sources. Table 12(A) applies for alternating-current sources, and Table 12(B) applies for direct-current sources. The power for power-limited fire alarm circuits shall be either (1) inherently limited, requiring no overcurrent protection, or (2) not inherently limited, requiring the power to be limited by a combination of power source and overcurrent protection.

As part of the listing, the PLFA power source shall be durably marked where plainly visible to indicate that it is a power-limited fire alarm power source. The overcurrent device, where required, shall be located at the point where the conductor to be protected receives its supply and shall not be interchangeable with devices of higher ratings. The overcurrent device shall be permitted as an integral part of the power source.

Table 12(A) PLFA Alternating-Current Power Source Limitations

Power Source Inherently Limited Power Source (Overcurrent Protection Not Required) Not Inherently Limited Power Source (Overcurrent Protection Required)
Circuit voltage Vmax (volts)(see Note 1) 0 through 20 Over 20 and through 30 Over 30 and through 100 0 through 20 Over 20 and through 100 Over 100 and through 150
Power limitations VAmax(volt-amperes)(see Note 1) 250 (see Note 2) 250 N.A.
Current limitations Imax (amperes)(see Note 1) 8.0 8.0 150/Vmax 1000/Vmax 1000/Vmax 1.0
Maximum overcurrent protection (amperes) 5.0 100/Vmax 1.0
Power source maximum nameplate ratings VA (volt-amperes) 5.0 × Vmax 100 100 5.0 × Vmax 100 100
Current (amperes) 5.0 100/Vmax 100/Vmax 5.0 100/Vmax 100/Vmax
Note: Notes for this table can be found following Table 12(B).

Table 12(B) PLFA Direct-Current Power Source Limitations

Power Source Inherently Limited Power Source (Overcurrent Protection Not Required) Not Inherently Limited Power Source (Overcurrent Protection Required)
Circuit voltage Vmax (volts)(see Note 1) 0 through 20 Over 20 and through 30 Over 30 and through 100 0 through 20 Over 20 and through 100 Over 100 and through 150
Power limitations VAmax (volt-amperes)(see Note 1) 250 (see Note 2) 250 N.A.
Current limitations I max (amperes)(see Note 1) 8.0 8.0 150/Vmax 1000/Vmax 1000/Vmax 1.0
Maximum overcurrent protection (amperes) 5.0 100/Vmax 1.0
Power source maximum nameplate ratings VA (volt- amperes) 5.0 × Vmax 100 100 5.0 × Vmax 100 100
Current (amperes) 5.0 100/Vmax 100/Vmax 5.0 100/Vmax 100/Vmax
Notes for Table 12(A) and Table 12(B)
1. V max, I max, and VA max are determined as follows:
V max: Maximum output voltage regardless of load with rated input applied.
I max: Maximum output current under any noncapacitive load, including short circuit, and with overcurrent protection bypassed if used. Where a transformer limits the output current, I max limits apply after 1 minute of operation. Where a current-limiting impedance, listed for the purpose, is used in combination with a non-power-limited transformer or a stored energy source, e.g., storage battery, to limit the output current, I max limits apply after 5 seconds.
VA max: Maximum volt-ampere output after 1 minute of operation regardless of load and overcurrent protection bypassed if used. Current limiting impedance shall not be bypassed when determining I max and VA max.
2. If the power source is a transformer, VA max is 350 or less when V max is 15 or less.
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