I am involved in the installation of a new sub main feeder cable that will replace an existing one that is damaged (phase lost) The cable connects at a substation and supplies five buildings that are situated at varying distances from the substation. The buildings are utilized for commercial activities, and they have typical loads such as LED lights and switch mode power supplies for PCs. A professional consultant has performed the design of the cable, and the cable calculations are executed using Amtech (Trimble) software. Nevertheless, I observed that the rating factors, load current and voltage drop section of the calculation all have a null value for the third harmonic current. I would appreciate your feedback on this matter.