ENWL012 - Investigation of Switchgear Ratings

Historically distribution networks are designed to cater for uni-directional power flow, predictable fault current paths and predictable fault current levels. The increasing amount of generation being connected to the network at all voltage levels will lead to bi-directional power flows, unpredictable fault current paths and higher fault current levels.

While our Respond project is investigating methods of controlling fault level particularly focusing on 11kV primary substation circuit breakers, this project developed a short circuit (fault withstand) performance 'envelope' for a range of the more commonly used distribution switchgear variants. This allows tailored replacement decisions based on actual fault levels at the equipment location and the actual capability of the equipment.

Timescales: December 2015 – July 2017.

Project documents