SPEN and SP Transmission - 33kV switch room upgrade/ all associated cable install and circuit transfers/ cleanse surrounding area of all redundant cables and switch gear/ demolish old 33kV switch room
- Excavate joint bays complying with all associated safe systems of work and ensuring compliance with HSG47. This was done in three locations to allow the existing circuits to be identified/ proved and tagged. Once this was complete these doubled up as the finish point for laying new 33kV circuits from the new 33kV switch room.
- Install ducts for 10 x 33kv circuits in trefoil, then pull/install cable from pre-dug joint bays to the rear of new 33kV switch room.
- Trace and expose all existing 33kV grid incomer circuits running from SP Transmission sub-station to old 33kV switch room. This allowed them to be cut and jointed to provide temporary interconnection between old and new 33kV switch gear.
- Single core cables were installed from the new 33kV switch gear out to jointing position for circuit transfers. Belac SPEN approved jointers completed all 33kV terminations in new switch room.
- Each of the existing circuits where identified/ isolated/ spiked and then cut and jointed onto the newly laid 33kV circuit by Belac SPEN approved jointers. This process was completed over a few days till all circuits were on the new switch gear.
- Excavate and clear large area of live cables in front of old switch room (37m x 17m x average 1.3m). This allowed all the live cables leaving the old switch room to be exposed, proved and when disconnected the cable was cut away and re-cycled via SPEN approved contactor. This meant that after the old switch gear had been removed and building demolished the complete area was clear for any future use.
- All newly installed ducting/cable and jointing position were accurately recorded and submitted to SPEN on project completion
- This was followed by a controlled backfill of approximately 1600 tons of material which was compacted in layer to meet RAUC specification, once complete an access road was reformed.