What is BS IEC 60287-2-1 – Calculation of thermal resistance about?
BS IEC 60287-2-1 is an international standard on electric cables and the calculation of the current rating. BS IEC 60287-2-1 presents formulae or calculation methods for thermal resistances.
BS IEC 60287-2-1 is solely applicable to the conditions of steady-state operation of cables at all alternating voltages, and direct voltages up to 5 kV, buried directly in the ground, in ducts, in troughs, or in steel pipes, both with and without partial drying-out of the soil, as well as cables in the air.
Who is BS IEC 60287-2-1 - Calculation of thermal resistance for?
BS IEC 60287-2-1 on the calculation of thermal resistance is relevant to:
- Cable manufacturers 
- Cable installation designers 
- Electrical engineers 
- Technical engineers 
- Local authorities 
Why should you use BS IEC 60287-2-1 - Calculation of thermal resistance?
BS IEC 60287-2-1 provides formulae for thermal resistance. The formulae given are essentially literal and designedly leave open the selection of certain important parameters. These may be divided into three groups:
- Parameters related to the construction of a cable for which representative values have been selected based on published work
- parameters related to the surrounding conditions which may vary widely, the selection of which depends on the country in which the cables are used or are to be used
- parameters which result from an agreement between manufacturer, user and which involve a margin for the security of service
BS IEC 60287-2-1 also provides a specification on the calculation of thermal resistances that are based on the calculation of the temperature of the cable surface.
Thus, BS IEC 60287-2-1 compliant calculation methods can help cable installation designers and engineers to determine the durability and performance of their electric cables which is helpful in the calculation of thermal resistance.
What’s changed since the last update?
BS IEC 60287-2-1:2015 replaces the first edition, this edition includes the following significant technical changes with respect to the previous edition:
- Inclusion of a reference to the use of finite element methods where analytical methods are not available for the calculation of external thermal resistance
- Explanation about SL and SA type cables
- calculation method for T3 for unarmoured three-core cables with extruded insulation and individual copper tape screens on each core
- Change of condition for X in 5.4
