IEC TS 62257-4:2015(E) provides a method for describing the results to be achieved by the electrification system independently of the technical solutions that could be implemented. The purpose is to provide a method to assist project contractors and project developers to select and design the electrification system for isolated sites while matching the identified needs, such as those described in IEC TS 62257-2. The main technical changes with regard to the previous edition are as follows:
- redefine the maximum AC voltage from 500 V to 1 000 V, the maximum DC voltage from 750 V to 1 500 V;
- removal of the limitation of 100 kVA system size.

This publication is to be read in conjunction with IEC 62257 series.