scope:

PURPOSE AND SCOPE

The purpose of this document is to set out the policy to be applied when selecting the ratings (values of key technical parameters) of transformers, reactors and quadrature boosters (including phase shifting transformers) to be used on the National Grid Electricity Transmission System. The scope covers new transformers, series and shunt reactors, quadrature boosters and phase shifters for connection at 400kV and 275kV. The policy is to be applied under all circumstances whether NG, consultants or suppliers carry out the system and application design. The policy should be applied, where possible, to plant connected to the transmission system but not owned or supported by NG, however this is not mandatory. The policy does not cover generator transformers.