NG TGN(E) 092 PDF

This document advises good operational practice for normal switching procedures to minimise trapped charge over-voltages produced in Gas Insulated Switchgear (GIS) Substations. The guidance is applicable to all GIS at 132 kV, 275 kV and 400 kV. On account of the low risks involved, this advice may be disregarded during emergency conditions.

When applying these procedures, the Control Person (Operations) should consider the wider implications and verify that normal operating standards are not contravened.