scope:

PURPOSE AND SCOPE

Protection and Automatic Switching Schedules (P&ASSs) are a set of documents, which summarise the protection and automatic switching arrangements fitted on National Grid's electricity transmission circuits.

This procedure defines the process for the preparation, amendment and issue of all Protection and Automatic Switching Schedules. It also defines the data which must be submitted to the National Grid Electricity System Operator (NGESO) detailing Operational Tripping Schemes (OTSs) and supports compliance with the relevant System Operator-Transmission Owner Code procedures, STCP 12-1 and STCP 19-4.