NG DH 04 PDF

PURPOSE AND SCOPE

The purpose of this handbook is to provide guidance on feeder backup protection settings deployed on the National Grid 400kV and 275kV transmission system. The application and protection setting policy for the most commonly occurring National Grid UK Electricity transmission arrangements is laid down in PS(T) 010. This design handbook provides guidance on backup feeder protection setting calculations for protection arrangements either not covered under PS(T) 010 or where guidance is required to ensure a consistent approach to this work. Guidance on backup protection settings for plain, teed and transformer feeders and feeders directly connected to the LV side of an SGT is provided in this document.