NG DH 05 PDF

PURPOSE AND SCOPE

The purpose of this handbook is to provide guidance on setting of Supergrid Transformer backup protection settings at National Grid 400kV and 275kV Substations. The application and setting policy for protection of the most commonly occurring National Grid UK Electricity transmission arrangements is laid down in PS(T) 010. This design handbook provides guidance on setting calculation for protection arrangements as specified in PS(T) 010 and those either not covered under PS(T) 010, or where settings deferring from the policy need to be applied to ensure co-ordination of grading.