Process
GroupMetropolitan were engaged as the Principal Design and Build Contractor to deliver the first phase of a long term strategy. The building was fed via a four sectioned switch panel, subsequently fed by four separate transformers. Team Critical modified the panel to couple neighbouring sections 1 & 2 and 3 & 4, followed by reconfiguring the HV generator control cabling and philosophy, introducing new LV generator PLC controls. A non-paralleling exercise was carried out, opening the main LV switch to sections 2 & 3 before closing the associated bus-coupler linking the new coupled sections, meaning that each coupled section was now fed via one incoming supply. We installed a new LV generator connection panel, allowing for connection of cabling between the existing main LV switchboard and the new generator connection box.
With the new connection box successfully linked to the building infrastructure, we used this to connect new temporary generator sets for site back-up power and performed on-site load testing to each set. This met a critical milestone set by the client to give LV back-up by a set date, critical to the client’s business operations.
We performed mains failure testing, proving the temporary generators protected the business by local simulation. Whilst the building was protected by the temporary generator sets, the installation of two new AVK 1350 kVA/ 1080 kW permanent LV containerised generators was carried out. This involved major civil works to provide suitable concrete plinths, and new security fencing to the perimeter.
Finally, once the new generators were installed, we planned and managed an out of hours change-over from the temporary LV generators to the new permanent LV sets. A full commissioning plan was produced and executed, which included performing load tests, building mains failure tests and multiple failure scenarios of the local HV to test the new PLC configuration.
The client was immensely happy with the finished project and thanked us for the collaborative approach that led to successful delivery. Phase Two of the project was awarded to us shortly after.
