NG TS 3.04.02 PDF

PURPOSE AND SCOPE

This document forms part of a suite of documents which define National Grid’s functional and performance requirements for new plant and equipment associated with electricity transmission.

The Specification defines the requirements for all round wire concentric lay ACSR, ACAR, AAAC and AACSR, and for Gap-type GZTACSR overhead line conductors, including their lubrication, procured for and installed on National Grid’s overhead lines as earthwires or phase conductors at 132 kV, 275 kV, 400 kV.

The following abbreviations and conductor designations according to BS EN 50182 are used throughout this document:

ACSR – Aluminium Conductor Steel Reinforced AL1/ST1A

ACAR – Aluminium Conductor Alloy Reinforced AL1/AL3

AAAC – All Aluminium Alloy Conductor AL5 *

AACSR – Aluminium Alloy Conductor Steel Reinforced AL5 */ST1A

* The mean resistivity of AL5 is 31.2 nΩ m. However, National Grid specify a lower resistivity alloy for phase conductors, see 1.2.2 below, for which an equivalent type is not specified in BS EN 50182.

The following abbreviation refers to the Gap-type conductor:

GZTACSR – “Gap” type ZT Aluminium Conductor Steel Reinforced

Composite Conductors in development not covered by this specification:-

ACCC - Aluminium Conductor Composite Core (CTC)

ACCR - Aluminium Conductor Composite Reinforced (3M)