BS 7769-2.1(1997) : 1997 AMD 13665

Committees responsible
National foreword
Introduction
Method
1 General
1.1 Scope
1.2 Symbols
2 Calculation of thermal resistances
2.1 Thermal resistance of the constituent parts of
    a cable, T1, T2 and T3
2.2 External thermal resistance T4
3 Digital calculation of quantities given graphically
3.1 General
3.2 Calculation of dts by means of a diagram
Tables
1 Thermal resistivities of materials
2 Values for constants Z, E and g for black
    surfaces of cables in free air
3 Absorption coefficient of solar radiation for
    cable surfaces
4 Values of constants U, V and Y
Figures
1 Diagram showing a group of q cables and their
    reflection in the ground-air surface
2 Geometric factor G for two-core belted cables with
    circular conductors
3 Geometric factor G for three-core belted cables with
    circular conductors
4 Values of constants, U, V and Y
Figures
1 Diagram showing a group of q cables and their
    reflection in the ground-air surface
2 Geometric factor G for two-core belted cables with
    circular conductors
3 Geometric factor G for three-core belted cables with
    circular conductors
4 Thermal resistance of three-core screened cables
    with circular conductors compared to that of a
    corresponding unscreened cable
5 Thermal resistance of three-core screened cables
    with sector-shaped conductors compared with that
    of a corresponding unscreened cable
6 Geometric factor G for obtaining the thermal
    resistances of the filling material between the
    sheaths and armour of SL and SA type cables
7 Heat dissipation coefficient for black surfaces of
    cables in air
8 Graph for the calculation of external thermal
    resistance of cables in air

Applies to conditions of steady-state operation of cables at all alternating voltages and direct voltages to 5 kV, buried in the ground directly, in troughs or steel pipes, with or without partial drying-out of soil, also in cables in air. Supplies formulae for thermal resistance.