N2XSEH 3x185 RM/25 12/20 kV
IEC nominal calculation, not manufacturer data. The thicknesses are the nominal values of the construction standards, added up layer by layer. A manufacturer's cable of the same name can differ by a few millimetres and by 10 to 20 % in weight: always check its datasheet before you specify, order or lay a cable.
By the IEC construction rules, N2XSEH 3x185 RM/25 12/20 kV comes to an overall diameter of about 78.0 mm and a weight of about 9,620 kg/km.
Open this cable in the designer Change any layer, see it in 3D and to scale, and download it.
Main dimensions
| Conductor | Copper 185 mm² RM, Ø 16.1 mm | IEC 60228 class 2 compacted, middle of min / max |
|---|---|---|
| Insulation | XLPE 5.5 mm | IEC 60502-2:2014 Tables 5-7, nominal insulation thickness |
| Diameter over insulation | 28.3 mm | |
| Core diameter | 31.5 mm | |
| Overall diameter | 78.0 mm | |
| Weight (approximate) | 9,620 kg/km |
Round conductors (IEC 60228 class 2 compacted; class 1 solid up to 10 mm²).
Layer by layer (inside out)
| # | Layer | Material | Thickness mm | Ø over mm | Source | How firmly |
|---|---|---|---|---|---|---|
| 1 | Conductor screen (semicon) | Semiconducting | 0.6 | 17.3 (on each core) | TKF at least 0.5 mm, Nexans under 1 mm | typical value, no rule |
| 2 | Insulation | XLPE | 5.5 | 28.3 (on each core) | IEC 60502-2:2014 Tables 5-7, nominal insulation thickness | read in the standard |
| 3 | Insulation screen (semicon) | Semiconducting | 0.8 | 29.9 (on each core) | TKF 0.8 mm, Nexans about 1 mm | typical value, no rule |
| 4 | Wire screen | Copper | 65 wires of 0.70 mm, 25 mm² | 31.5 (on each core) | copper wire screen: wires at least 0.5 mm, 0.1 mm counter-helix tape | typical value, no rule |
| 5 | Filler | PP | fills the space between the cores | 67.8 | ||
| 6 | Inner covering / bedding | Halogen-free (LSZH) | 1.8 | 71.4 | IEC 60502 Table 8, extruded inner covering by the fictitious diameter over the laid-up cores (Annex A) | read in the standard |
| 7 | Sheath | Halogen-free (LSZH) | 3.3 | 78.0 | IEC 60502 clause 13 / 14.3, oversheath: 0.035 D + 1.0 mm, D the fictitious diameter (Annex A) | read in the standard |
Diameters add up the nominal layers. Where IEC 60502 sizes a layer by the fictitious diameter of its Annex A, the calculated diameter is used instead, which can move a value one step. Sources and page numbers: research/mv-dimensions in the site repository.
Weight, by part
| Conductors | 5,130 kg/km |
| Metal screens and armour | 690 kg/km |
| Insulation, semicon, tapes, fillers and sheaths | 3,800 kg/km |
| Total | 9,620 kg/km |
|---|
Each layer's cross-section times its density; stranded conductors, laid-up cores and helical wires count 2 % longer than the cable. Densities: copper 8.89 and aluminium 2.703 g/cm³ (the values of IEC 60028 and IEC 60889); XLPE 0.92, PE 0.94, PVC 1.45, semicon 1.12, steel 7.85 g/cm³ (usual compound values).