RFI2 24kV Ring Main Units

This request for information is intended for investigating: * The availability of SF6-free Ring Main Units (RMUs) to be implemented in the Stedin distribution grid. * The feasibility of Stedin requirements that are currently under construction.

The RMUs must have a rated voltage of 24kV, rated busbar current of 630A and able to resist 20kA/1 short-circuit current. All RMUs are composed from a combination of Load Break Switch feeders and Circuit Breaker feeders. Fuse feeders are out of scope.

The RMUs are intended to be used as: * Standard 3 panel configurations in ring topology with self-powered protection relay. - 630/1000kVA distribution stations. - ≤1750kVA client connections with metering.

* Standard configurations with protection relay requiring auxiliary voltage. - 3-panel for client connections 1.75-10.00MVA with metering. - 6-panel configurations.

* Freely-configurable single panel designs for brownfield/renovation purposes.

The RMUs will be both applied in prefabricated substations with downwards pressure relief and traditional substations with upwards pressure relief. The RMUs are to be delivered at the Stedin warehouse. Installation and commissioning is intended to be Stedin scope.