Surge strength of symmetric cable with monolithic polyethylene insulation of quads

The lightning resistance of MKP sub m AS h sub p-4x4x1.05 + 2x0.7 symmetric railroad communication cables operating along the Baykal-Amur line was evaluated in terms of the dielectric strength of their insulation system, in failure-free operation. The insulation system in these cables consists of monolithic polyethylene around each quad core and polyethylene sleeving around each aluminum sheath. Experimental data for this evaluation had been obtained by measurement of the voltage between conductor bundle and sheath, this voltage being the highest during a lightning stroke, not only along cable segments between repeater points but also in splices and in potheads. A comparison with similar data in MKSA sub p SH sub p 4x4x1.2 cables indicates that the tested MKP sub m AS h sub p cables have a much higher surge strength.