BS EN 50525-2-31 refers the electric cables — Low voltage energy cables of rated voltages up to and including 450/750 V (U0/U)
Part 2-31: Cables for general applications— Single core non-sheathed cables with thermoplastic PVC insulation
EN 50525-2-31 applies to non-sheathed single-core cables insulated with thermoplastic (PVC) insulation.
The BS EN 50525 cables are of rated voltages U0/U up to and including 450/750 V. The cables are intended for fixed wiring applications.
Please be noted Cables rated 450/750 V may be used at 600/1 000 V when this cable is used in fixed installations with mechanical protection, within switchgear and control gear.
The maximum conductor operating temperatures for the cables in this standard is 70 °C and 90 °C.