Single Core 70°C Thermoplastic Insulated Cables, Non Armoured, With or Without Sheath (COPPER CONDUCTORS)

Tables Apply to: ST91X, 6491X, 6181Y, TRI-RATED (when installed in conduit or trunking)

CURRENT-CARRYING CAPACITY (amperes)

Conductor Cross Sectional Area
Reference Method A (enclosed in conduit in thermally insulating wall etc.)
Reference Method B (enclosed in conduit on a wall or in trunking etc.)
Reference Method C (clipped direct)
Reference Method F (in free air or on a perforated cable tray horizontal or vertical etc.)
Touching
Spaced by one diameter
2 cables, single-phase a.c. or d.c.
3 or 4 cables, three-phase a.c.
2 cables, single-phase a.c. or d.c.
3 or 4 cables, three-phase a.c.
2 cables, single-phase a.c. or d.c. flat and touching
3 or 4 cables, three-phase a.c. flat and touching or trefoil
2 cables, single-phase a.c. or d.c. flat
3 cables, three-phase a.c. flat
3 cables, three-phase a.c. trefoil
2 cables, single-phase a.c. or d.c. or 3 cables three-phase a.c. flat
Horizontal
Vertical
1
2
3
4
5
6
7
8
9
10
11
12
(mm2)
(A)
(A)
(A)
(A)
(A)
(A)
(A)
(A)
(A)
(A)
(A)
1
11
10.5
13.5
12
15.5
14
-
-
-
-
-
1.5
14.5
13.5
17.5
15.5
20
18
-
-
-
-
-












2.5
20
18
24
21
27
25
-
-
-
-
-
4
26
24
32
28
37
33
-
-
-
-
-
6
34
31
41
36
47
43
-
-
-
-
-
10
46
42
57
50
65
59
-
-
-
-
-
16
61
59
76
68
87
79
-
-
-
-
-












25
80
73
101
89
114
104
131
114
110
146
130
35
99
89
125
110
141
129
162
143
137
181
162
50
119
108
151
134
182
167
196
174
167
219
197
70
151
136
192
171
234
214
251
225
216
281
254
95
182
164
232
207
284
261
304
275
264
341
311
120
210
188
269
239
330
303
352
321
308
396
362
150
240
216
300
262
381
349
406
372
356
456
419
185
273
245
341
296
436
400
463
427
409
521
480
240
321
286
400
346
515
472
546
507
485
615
569
300
367
328
458
394
594
545
629
587
561
709
659












400
-
-
546
467
694
634
754
689
656
852
795
500
-
-
626
533
792
723
868
789
749
982
920
630
-
-
720
611
904
826
1,005
905
855
1,138
1,070
800
-
-
-
-
1,030
943
1,086
1,020
971
1,265
1,188
1000
-
-
-
-
1,154
1,058
1,216
1,149
1,079
1,420
1,337

VOLTAGE DROP (per ampere per metre)

Conductor Cross Sectional Area
2 cables d.c
2 cables, single-phase a.c.
3 or 4 cables, three-phase a.c.
Reference Methods A&B (enclosed in trunking)
Reference Methods C&F (clipped direct, on tray, or in free air)
Reference Methods A&B (enclosed in conduit or trunking)
Reference Methods C&F (clipped direct, on tray or in free air)
Cables touching
Cables spaced*
Cables touching, trefoil
Cables touching, flat
Cables spaced*, flat
1
2
3
4
5
6
7
8
9
(mm2)
(mV/A/m)
(mV/A/m)
(mV/A/m)
(mV/A/m)
(mV/A/m)
(mV/A/m)
(mV/A/m)
(mV/A/m)
1
44
44
44
44
38
38
38
38
1.5
29
29
29
29
25
25
25
25
2.5
18
18
18
18
15
15
15
15
4
11
11
11
11
9.5
9.5
9.5
9.5
6
7.3
7.3
7.3
7.3
6.4
6.4
6.4
6.4
10
4.4
4.4
4.4
4.4
3.8
3.8
3.8
3.8
16
2.8
2.8
2.8
2.8
2.4
2.4
2.4
2.4


r
x
z
r
x
z
r
x
z
r
x
z
r
x
z
r
x
z
r
x
z
25
1.75
1.8
0.33
1.8
1.75
0.2
1.75
1.75
0.29
1.8
1.5
0.29
1.55
1.5
0.175
1.5
1.5
0.25
1.55
1.5
0.32
1.55
35
1.25
1.3
0.31
1.3
1.25
0.195
1.25
1.25
0.28
1.3
1.1
0.27
1.1
1.1
0.17
1.1
1.1
0.24
1.1
1.1
0.32
1.15
50
0.93
0.95
0.3
1
0.93
0.19
0.95
0.93
0.28
0.97
0.81
0.26
0.85
0.8
0.165
0.82
0.8
0.24
0.84
0.8
0.32
0.86
70
0.63
0.65
0.29
0.72
0.63
0.185
0.66
0.63
0.27
0.69
0.56
0.25
0.61
0.55
0.16
0.57
0.55
0.24
0.6
0.55
0.31
0.51
95
0.46
0.49
0.28
0.56
0.47
0.18
0.5
0.47
0.27
0.54
0.42
0.24
0.48
0.41
0.155
0.43
0.41
0.23
0.47
0.4
0.31
0.51
120
0.36
0.39
0.27
0.47
0.37
0.175
0.41
0.37
0.26
0.45
0.33
0.23
0.41
0.32
0.15
0.36
0.32
0.23
0.4
0.32
0.3
0.44
150
0.29
0.31
0.27
0.41
0.3
0.175
0.34
0.29
0.26
0.39
0.27
0.23
0.36
0.26
0.15
0.3
0.26
0.23
0.34
0.26
0.3
0.4
185
0.23
0.25
0.27
0.37
0.24
0.17
0.29
0.24
0.26
0.35
0.22
0.23
0.32
0.21
0.145
0.26
0.21
0.22
0.31
0.21
0.3
0.36
240
0.18
0.195
0.26
0.33
0.195
0.165
0.25
0.185
0.25
0.31
0.17
0.23
0.29
0.16
0.145
0.22
0.16
0.22
0.27
0.16
0.29
0.34
300
0.145
0.16
0.26
0.31
0.15
0.165
0.22
0.15
0.25
0.29
0.14
0.23
0.27
0.13
0.14
0.19
0.13
0.22
0.25
0.13
0.29
0.32
400
0.105
0.13
0.26
0.29
0.12
0.16
0.2
0.115
0.25
0.27
0.12
0.22
0.25
0.105
0.14
0.175
0.105
0.21
0.24
0.1
0.29
0.31
500
0.086
0.11
0.26
0.27
0.098
0.155
0.185
0.093
0.24
0.26
0.1
0.22
0.25
0.086
0.135
0.16
0.086
0.21
0.23
0.081
0.29
0.3
630
0.068
0.094
0.25
0.27
0.081
0.155
0.175
0.076
0.24
0.25
0.08
0.22
0.24
0.072
0.135
0.15
0.072
0.21
0.22
0.066
0.28
0.29
800
0.053
-


0.068
0.15
0.165
0.061
0.24
0.25
-


0.06
0.13
0.145
0.06
0.21
0.22
0.053
0.28
0.29
1000
0.042
-


0.059
0.15
0.16
0.05
0.24
0.24
-


0.052
0.13
0.14
0.052
0.2
0.21
0.044
0.28
0.28

NOTE: *Spacings larger than one cable diameter will result in a larger voltage drop.

DISCLAIMER: This information has been supplied in good faith and the upmost care has been taken to ensure the data is accurate in it's derivation from BS7671.
However, this information should not be considered as a substitute for BS7671, which should always be referred to. It remains the responsibility of the user to ensure all data and assumptions are correct and that any cable used is suitable for its intended purpose.

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