Difference voltages and circulating currents in pairs of cores in auxiliary multicore cables

At power-system frequencies there may be sufficient imbalance in two cores of an auxiliary cable so that, when used as a pair, current circulates which impairs the functioning of terminal equipment. It is shown that the technique of calculating voltages induced longitudinally in auxiliary cables can be extended to determine the difference quantities in cores. Simple expressions are developed to determine difference voltages and circulating currents, and these are shown to give results very close to measured values. Factors which modify these quantities in practice are indicated.