Replacement of HV/LV Transformers and Main LV Switchboards Two

Client – MJ Lonsdale Ltd

Value – £25k

FiveFour Engineering Services were instructed to undertake a feasibility study to consider the various options for the replacement of the landlord’s Main Low Voltage (LV) switchboards, rising busbars and sub-main distribution panels at The Department for Education, 20 Great Smith Street, Westminster,London,SW1P 3BT and to issue a report, complete with conclusions, recommendations and budget cost analysis.

Initial site inspections were carried out during May/June 2021.

The FiveFour Engineering Services survey offered 4 options:

Option A – Do Nothing. There would be no disruption to existing services and no replacement costs, but there was a risk that maintenance costs, and the risk of failure, would increase year on year.

Option B – Leave the existing main switchboards and busbars in position and provide new Protective Devices and tap-off units within the existing assemblies.

This offered the lowest cost option with the life expectancy of the existing main switchboards and busbars remaining the same, but the protective devices and tap-off units would be future-proofed for at least another 15 years. There would be minor disruption to existing services, during the replacement of the existing protective devices and tap-off units.

Option C – Provide new locations for the main LV switchboards and rising busbars and replicate the electrical infrastructure.

Under this option the existing main switchboards and busbars would be future-proofed for at least another 20 years. The shut-down periods would be minimised to include change-over periods only. However, as new locations would need to be found for the main switchboards and risers, the alterations required to the sub-mains cables would be significant and might require complete replacement. Core drilling would be required at each level of the building.

Option D – Remove and replace the existing main switchboards and busbars for modern equivalents in a series of phased shutdowns.

The life expectancy of the existing main LV switchboards, busbars and tap-offs would be future-proofed for at least another 20 years. Disruption to existing tenants electrical supplies would be significant and require a number of pre-arranged shut-down periods. The option would require the complete removal of the existing main LV Switchboards and rising busbars.

Our final recommendation was that the existing main LV Switchboards, busbars and tap-off units should be removed and replaced for modern equivalents, supplied and installed as detailed in Option “C”, with a budget sum agreed upon further scope definition.

FiveFour Engineering Services are happy to undertake cost/benefit feasibility studies in preparation for the client scope of works document to be prepared for tender or to undertake the works on behalf of the client/end user.