Verification of Cables In Steel Pipes

GRØFT models were verified with reference to the IEC 60287 ¹ for the cable rating calculation of cables installed in magnetic pipes. For the range of the application of the IEC standard, GRØFT models are in line with the IEC calculations. Furthermore, GRØFT is based on finite element method (FEM), therefore use of the functionality of magnetic pipes in the software may be used for more complex cable arrangement not covered by the IEC.

Summary of Verification Report “Cables In Steel Pipes – Verification With IEC 60287”

GRØFT models correlates well with the IEC calculations. Resulting heat losses in pipes for GRØFT models are close to the IEC calculations for all presented cases. Several minor discrepancies for resulting temperature of conductor between the analytical and the GRØFT models are observed. This is the consequence of different placement of the cables in pipe. The geometric setup is of a major relevance in terms of losses in pipe, conductor and sheath.

Furthermore, the analytical formula found in IEC does not account for the variation of the relative permeability of pipe material. In GRØFT this parameter may be defined by the user.

Verification Report

The complete report, “Cables In Steel Pipes – Verification With IEC 60287”, is found here.

Sources

Footnotes

1. NEK IEC 60287-1-1:2006 Calculation of the current rating Part 1-1: Current rating equations (100% load factor) and calculation of losses, Norsk Elektroteknisk Komite. ↩