scope:

This part of IEC Guide 111 is a horizontal publication which gives guidance for the harmonization of product and system standards for HV substations (higher than 1 kV). It addresses AC equipment which is found in high-voltage (HV) substations in most cases.

This document contains recommendations for common specifications for all HV substation product and system standards, each of which is augmented by the technical background specific to each technical committee, which naturally retains freedom in its technical choices.

This document is applicable when developing product and systems standards for HV power electronic equipment for the AC part of the substation.

NOTE 1 IEC Guide 111-2 relating to DC (direct current) is under development. Once published, IEC Guide 111-2 will be applicable when developing product and systems standards for the HVDC part of the substation.

NOTE 2 The IEC Standardization Management Board (SMB) has decided that Guides such as this one can have mandatory requirements which shall be followed by all IEC committees developing technical work that falls within the scope of the Guide, as well as guidance which may or may not be followed. The mandatory requirements in this Guide are identified by the use of "shall". Statements that are only for guidance are identified by using the verb "should". (See ISO/IEC Directives, IEC Supplement Part 1, A.1.1.)