On four-conductors low voltage cables ampacity in balanced and unbalanced nonsinusoidal conditions

In this paper the problem of the low voltage cables thermal sizing in nonsinusoidal steady-state operating conditions is considered. In particular, the case of four conductors low voltage cables feeding groups of single-phase nonlinear loads such as desktop computers, TV, light-dimmers and so on is taken into account. Particular attention is paid to show the influence of the neutral conductor configuration on the cable ampacity. Numerical applications referred to cables of low voltage distribution systems are presented and discussed in order to show the influence of the harmonics on the cable ampacity.