NG TS 3.24.63
National Grid Technical Specifications - Mesh Station DAR and Plant Isolation
|Publication Date:||1 May 2001|
This specification describes the functional and performance requirements for post-fault automatic switching (DAR and plant isolation) for National Grid's Mesh type substations. For the purposes of this specification Mesh type substations encompasses: four-switch mesh, three-switch with bypass, singleswitch, banked plant substations and other related configurations operating at 400, 275 and 132 kV.
Post-fault, protection initiated, automatic switching encompasses automatic isolation of Mesh Corner connected feeders, transformers or other plant by opening associated HV disconnectors as required followed by Delayed Automatic Reclosure (DAR) of Mesh Corner HV and LV circuit breakers as required to re-energise remaining non-isolated plant.
Where specified in the contract, the automatic switching functionality shall accommodate variations in plant topology and sizing.