Single Conductor - Underground Ducts

Single conductor cable underground ducts

Single conductor cable
underground ducts

Open circuited shield operation, i.e. shields bonded and grounded at one point only.

One cable per non-metallic duct, all
cables equally loaded and in outside ducts only.

Earth ambient temperature 20°C
Earth thermal resistivity RHO 90
100% Load Factor

Depth of burial - 30” to top of duct bank with ducts on 7 1/2“ centers.

 

One circuit — three cables in separate ducts

one conductor Copper - underground ducts one conductor Aluminum - underground ducts

Conductor
Size
AWG-kcmil

Non-Shielded

Shielded

600-2000 Volts
Ampacity

2001-5000 Volts
Ampacity

5001-35000 Volts
Ampacity

90° C
(194°F)

90° C
(194°F)

105°C
(221°F)

90° C
(194°F)

105°C
(221°F)

8.........
6
.........
4
.........
2
.........
1
.........
1/0
.........
2/0
.........
3/0
.........
4/0
.........
250
.........
350
.........
500
.........
750
.........
1000
.........
1250
.........
1500
.........
1750
.........
2000.....
....

80.........
104
.........
135
.........
176
.........
202
.........
231
.........
264
.........
301
.........
345
.........
379
.........
461
.........
564
.........
706
.........
823
.........
920
.........
1004
.........
1077
.........
1139.....
....

80...
106
...
137
...
178
...
204
...
233
...
265
...
302
...
345
...
379
...
460
...
561
...
702
...
816
...
913
...
995
...
1066
...
1125
...

86...
114
...
148
...
192
...
220
...
251
...
286
...
326
...
372
...
409
...
496
...
605
...
757
...
880
...
984
...
1073
...
1149
...
1213
...

...
106
...
137
...
179
...
204
...
232
...
265
...
302
...
344
...
378
...
457
...
557
...
695
...
807
...
902
...
981
...
1051
...
1109
...

.....
114
...
148
...
193
...
220
...
250
...
286
...
326
...
371
...
407
...
493
...
600
...
749
...
870
...
972
...
1058
...
1133
...
1196
...

Non-Shielded

Shielded

600-2000 Volts
Ampacity

2001-5000 Volts
Ampacity

5001-35000 Volts
Ampacity

90° C
(194°F)

90° C
(194°F)

105°C
(221°F)

90° C
(194°F)

105°C
(221°F)

62.........
81
.........
105
.........
137
.........
157
.........
180
.........
205
.........
235
.........
269
.........
296
.........
360
.........
442
.........
556
.........
653
.........
738
.........
813
.........
880
.........
940....
.....

62...
83
...
107
...
139
...
159
...
181
...
206
...
236
...
269
...
296
...
359
...
440
...
553
...
648
...
732
...
806
...
872
...
930
...

67...
89
...
115
...
150
...
171
...
195
...
222
...
254
...
290
...
319
...
387
...
474
...
596
...
699
...
789
...
869
...
940
...
1003
...

.......
83
...
107
...
139
...
159
...
181
...
206
...
235
...
268
...
295
...
357
...
436
...
547
...
641
...
723
...
795
...
859
...
917
...

...
89
...
115
...
150
...
171
...
195
...
222
...
253
...
289
...
318
...
385
...
470
...
590
...
691
...
779
...
857
...
926
...
989
...

 

Two circuits — six cables in separate ducts

one conductor Copper - underground ducts one conductor Aluminum - underground ducts

Conductor
Size
AWG-kcmil

Non-Shielded

Shielded

600-2000 Volts
Ampacity

2001-5000 Volts
Ampacity

5001-35000 Volts
Ampacity

90° C
(194°F)

90° C
(194°F)

105°C
(221°F)

90° C
(194°F)

105°C
(221°F)

8.........
6.........
4.........
2.........
1.........
1/0.........
2/0.........
3/0.........
4/0.........
250.........
350.........
500.........
750.........
1000.........
1250.........
1500.........
1750.........
2000.........

71.........
93.........
120.........
155.........
176.........
201.........
226.........
260.........
296.........
325.........
391.........
475.........
589.........
682.........
759.........
824.........
880.........
928.........

71...
94...
121...
156...
177...
202...
229...
260...
296...
324...
390...
472...
585...
676...
752...
816...
871...
916...

77...
101...
130...
168...
191...
218...
247...
280...
319...
349...
420...
509...
631...
729...
811...
880...
939...
987...

...
94...
121...
156...
177...
201...
228...
259...
294...
322...
387...
468...
579...
668...
742...
804...
858...
902...

...
101...
130...
168...
191...
217...
246...
279...
317...
347...
417...
505...
624...
720...
800...
867...
925...
972...

Non-Shielded

Shielded

600-2000 Volts
Ampacity

2001-5000 Volts
Ampacity

5001-35000 Volts
Ampacity

90° C
(194°F)

90° C
(194°F)

105°C
(221°F)

90° C
(194°F)

105°C
(221°F)

56.........
72.........
93.........
121.........
138.........
157.........
178.........
203.........
231.........
253.........
306.........
372.........
464.........
541.........
608.........
667.........
719.........
766.........

56...
73...
94...
121...
138...
157...
178...
203...
231...
253...
304...
370...
461...
537...
603...
661...
712...
757...

60...
79...
101...
130...
149...
169...
192...
219...
249...
273...
328...
399...
497...
579...
650...
713...
768...
816...

...
73...
94...
121...
138...
157...
178...
202...
230...
251...
302...
367...
456...
530...
595...
651...
702...
746...

...
79...
101...
130...
149...
169...
192...
218...
248...
271...
326...
396...
492...
571...
641...
702...
757...
804...

 

Three circuits — nine cables in separate ducts

one conductor Copper - underground ducts one conductor Aluminum - underground ducts

Conductor
Size
AWG-kcmil

Non-Shielded

Shielded

600-2000 Volts
Ampacity

2001-5000 Volts
Ampacity

5001-35000 Volts
Ampacity

90° C
(194°F)

90° C
(194°F)

105°C
(221°F)

90° C
(194°F)

105°C
(221°F)

8.........
6.........
4.........
2.........
1.........
1/0.........
2/0.........
3/0.........
4/0.........
250.........
350.........
500.........
750.........
1000.........
1250.........
1500.........
1750.........
2000.........

68.........
87
.........
112
.........
145
.........
165
.........
188
.........
213
.........
242
.........
275
.........
301
.........
362
.........
438
.........
541
.........
625
.........
694
.........
752
.........
803
.........
845
.........

68...
88
...
114
...
146
...
166
...
188
...
213
...
242
...
274
...
300
...
360
...
435
...
537
...
619
...
687
...
744
...
794
...
834
...

73...
95
...
123
...
157
...
179
...
203
...
230
...
261
...
295
...
323
...
388
...
469
...
579
...
667
...
741
...
802
...
856
...
899
...

...
88
...
114
...
146
...
165
...
188
...
212
...
241
...
273
...
298
...
357
...
431
...
531
...
611
...
678
...
733
...
781
...
821
...

...
95
...
123
...
157
...
178
...
203
...
229
...
260
...
294
...
321
...
385
...
465
...
572
...
659
...
731
...
790
...
842
...
885
...

Non-Shielded

Shielded

600-2000 Volts
Ampacity

2001-5000 Volts
Ampacity

5001-35000 Volts
Ampacity

90° C
(194°F)

90° C
(194°F)

105°C
(221°F)

90° C
(194°F)

105°C
(221°F)

53.........
68
.........
88
.........
113
.........
129
.........
146
.........
166
.........
188
.........
214
.........
235
.........
282
.........
343
.........
426
.........
496
.........
556
.........
609
.........
656
.........
698
.........

53...
69
...
88
...
114
...
129
...
147
...
166
...
188
...
214
...
234
...
281
...
341
...
423
...
492
...
551
...
603
...
649
...
689
...

57...
74
...
95
...
123
...
139
...
158
...
179
...
203
...
231
...
252
...
303
...
368
...
456
...
530
...
594
...
650
...
700
...
743
...

...
69
...
88
...
113
...
129
...
146
...
165
...
188
...
213
...
233
...
279
...
337
...
418
...
485
...
544
...
594
...
639
...
678
...

...
74
...
95
...
122
...
139
...
157
...
178
...
203
...
230
...
251
...
301
...
363
...
451
...
523
...
586
...
640
...
689
...
731
...