Induced Voltages and Power Losses in Single-Conductor Armored Cables

Single-conductor armored cables are often used to carry high currents in buildings. This paper presents an experimental investigation into both induced voltages and cable resistances associated with the installation of these cables within the buildings. Both induced armor voltages and cable resistances under different installation practices were measured at both power frequency and its harmonic frequencies. The impact of cable formation, bonding arrangement, and cable supporting method on these issues was addressed and illustrated experimentally via 185-mm² (365-kcmil) single-conductor armored copper stranded cables. The standing voltage is generally small for the armored cables used in the buildings. The power losses increase significantly when the cable armor is bonded at two cable ends, particularly in the case of rich harmonic currents in the cables. Recommendations are finally provided for the installation of single-conductor armored cables in buildings.