Five years after the first publication and based on the initiative of the VGB technical group “Electrical Equipment”, the necessity of a revision to the VGB Standards “Electrical Unit Protection” (VGB-SO25) was discussed. As a result, it was decided to do a revision and release a new publication, using the new numbering system VGB-S-162.

The emphases of the revision were the topics asynchronous system feed-in (or network supply), open phase, (detection of loss of phase due to broken conductors, poleslip
protection, asymmetry protection, unbalanced load protection), standardisation of terms, updating based on operating experience, supplementing the current regulations
(“Netcodes”), “Technische Anwendungsregeln des FNN, e.g. VDE-AR-N 4130”,”Sys-StabV”).