PSOM 4.3 – Standard Switching Terminology and Approved Abbreviations

PSOM 4.3 – Standard Switching Terminology and Approved Abbreviations Midlands Area - Key Changes

Introduction • Changes to the PSOM prompted by: • The introduction of Power on Fusion (PoF) as the CN Control System. • Differences between CIRAS and PoF. • The output of a working group set up to evaluate the smartest options going forward. • In addition and outside the PSOM some Switching device descriptions have been standardised within Power on Fusion.

Principles Established (Underground) • The use Gas (GS), Oil(OS) Fault Making (FMS) to be replaced with Switch (SW). • The term Switch Fuse (SF) remains. • The use of Gas (GCB), Oil (OCB) Vacuum (VCB) to be replaced with Circuit Breaker (CB). • The terminology Open to OFF, Close to ON to be replaced with the instruction open or close followed by the consequence of the action i.e. to make parallel, possible fault. • The terminology for Earthing will be Open from Earth & Close to Earth.

Principles Established (Overhead) • ABSD will be the terminology for handle & hook stick operated overhead Air Break Switches • All Pole Mounted Reclosures will be referred to as a PMR • All other pole mounded switches will be called Switch Disconnectors • DOEF’s, PDFI, PDSF will be known as HV fuses • Links will be known as HV Links • ERICS will be called ASLs

Switching Instructions (ON/OFF) • Typically broken down to two parts the operation and consequence;

HV Isolation Instructions

LV Operation Instructions Generators

Safety Documents Field Control

Cables Testing NER’s

Overhead Activities Miscellaneous

PSOM 4.3 – Standard Switching Terminology and Approved Abbreviations