Page 489 - 2025/26 Catalogue

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 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)
Click here for a PDF Useful Information - Current Carrying Capacity of page 489
VOLTAGE DROP (per ampere per metre)
1 44
1.5 29
2.5 18
4 11
44 44
29 29
18 18
11 11
44 38 38 38 38
29 25 25 25 25
18 15 15 15 15
11 9.5 9.5 9.5 9.5
6 7.3 7.3 7.3
10 4.4 4.4 4.4
16 2.8 2.8 2.8
7.3 6.4
4.4 3.8
2.8 2.4
6.4 6.4 6.4
3.8 3.8 3.8
2.4 2.4 2.4
rxzrxzrxzrxzrxzrxzrxz
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 its derivation from BS 7671.
However, this information should not be considered as a substitute for BS 7671, 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.
WARNING
Current ratings are dependent on the type of installation and those shown are for guidance only.
For precise cable ratings for a particular installation refer to the current edition of the IEE Wiring Regulations.
For more information visit www.electric-center.co.uk
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