IEC 60228 & BS EN 60228 Stranding For Insulated Cables

Below shows the number of strands and strand size for each conductor size according to IEC/BS EN 60228.

It is important to note the following:

• For Classes 1 & 2 the number of strands is obligatory according to IEC/BS EN 60228.
• Classes 5 & 6 gives the maximum strand diameter, it is acceptable to have fewer strands so long as the conductor
  resistance does not exceed the maximum shown below.
• Standard IEC/BS EN 60228 gives the maximum resistance in Ω/km that is permissible for bare/plain copper conductors.