Summary
Installation of cables in unfilled plastic ducts is a commonly used installation method both for land cables in trench and Horizontal Directional Drilling (HDD), as well as offshore cables at landfall. The standard for cable rating calculations, IEC 60287-2-1 [1], provides a method for calculation of unfilled ducts. The method is limited to cables with diameters between 25 mm and 100 mm, or between 75 mm to 125 mm for equivalent diameter of three cables in same duct. The paper presents Finite Element Method (FEM) simulations of different cable and duct sizes in different installations and compares with results from IEC method. The method for unfilled ducts in IEC 60287-2-1 is shown to give matching or conservative results also for cable diameters outside of its defined range for all installations of single or separated plastic ducts.
Read more Read lessFor touching ducts in trefoil, the effect of disturbed heat transfer from the pipe surface is not treated and therefore results in an underestimation of the thermal resistance. A compensation factor of 1.25 on T4′ (Thermal resistance between cable surface and duct surface) is found appropriate to compensate for this effect. For metal conduits the IEC method gives a nonconservative result while for water filled ducts the method gives a thermal resistance that is two to four times larger than FEM. New constants are proposed to give the method better accuracy for these cases.
Additional informations
| Publication type | Session Materials |
|---|---|
| Reference | B1_11737_2026 |
| Publication year | |
| Publisher | CIGRE |
| Country | Sweden |
| Study committees | |
| File size | 993 KB |
| Price for non member | 30 € |
| Price for member | 30 € |
Authors
THYRVIN Ola - NKT
Keywords
