Explains the fundamentals of oil-filled cables current rating calculations to IEC 60287 and provides and example calculation for a 400 kV single core cable.

Sheath bonding is one of the most important design aspects for high-voltage cable power transmission. Solidly, single-point, and cross-bonded systems are explained.

Crossing multiple cables or heat sources at a crossing angle causes a current rating reduction, calculated using IEC Standard 60287.

New 13 kV power circuits will be installed in an unfilled trough with ventilated covers. These new circuits will cross with existing buried 400 kV cables at approximately 90 degrees with a continuous current rating requirement of 1136 MVA (1640 A) per phase for all seasons.

Most power cables have a design life of between 20 to 30 years. If the cables are not fully loaded, they are expected to last beyond their design life. The insulation is the weakest part of a cable. Montsinger's Rule states: Insulation life is halved by a temperature increase of 8 to 10 ˚C. An example calculation using the Arrhenius equation is provided.

This article explains how to calculate the current rating of cables in J-tubes. Typically J-tubes are the thermal bottleneck of submarine power cable routes.

A new calculation method based on FEM and IEC 60287 for current rating of HV cables in soils with multiple different thermal resistivities is explained with an example calculation. Modelling the different soil thermal resistivity zones (multiple backfills) is important for obtaining accurate cable current ratings.

The methods for calculating the current rating of multiple cables installed in ventilated tunnels are explained with example calculations. Overall tunnel length and air velocity inside the tunnel have a significant impact on cable current ratings.

The calculation of current ratings for groups of (multiple) cable circuits require the quantification of the mutual heating component between the groups of circuits. This example is for multiple groups of circuits in air on the same cable ladder. This article will discuss the IEC 60287 approach.