Eaton has supplied nine 11kV packaged substations, ranging from 630MVA to 1600MVA,for Europe's largest private finance initiative (PFI), the £560 million Colchester Garrison project.
Eaton has supplied nine 11kV packaged substations for Europe’s largest private finance initiative (PFI), the £560 million Colchester Garrison project. The substations, worth around £500,000, include cast resin transformers and low voltage switchboards.
Colchester has been a military centre since pre-Roman times. It was here that the Roman legions defeated the forces of Caratacus in AD41 and established their own fortress and Britain’s first City, Camulodunum. In AD60 the Iceni Queen, Boadicea, destroyed the fortress but the rebellion was soon crushed. The existing Garrison includes listed buildings dating back to the 19th Century. The new Garrison will include around 137 buildings providing modern living accommodation, working, training, recreation, education and welfare facilities for 3,500 military personnel and over 2,000 civilians with 16th Air Assault Brigade.
The PFI contract, awarded to RMPA Services Plc – a consortium of Sir Robert McAlpine Ltd, Atkins, Sodexho Alliance and HSBC infrastructure – will be worth around £2 billion over its 35-year life. Sir Robert McAlpine Ltd. is the design and build contractor for the construction of the new Garrison. The packaged substations form part of the infrastructure works for which Sir Robert McAlpine’s sub contractor is White Mountain Quarries Ltd. Eastern Contracting is responsible to White Mountain Quarries for installing electrical, gas and water services under a £4 million sub-contract.
Eaton was responsible for both supply and installation of the nine packaged substations comprising 11kV/415V cast resin transformers and Memform Form 4 Type 6 low voltage switchboards. The substations vary in size from 630MVA to 1600MVA. The transformers are close-coupled to the switchboards, with busbar connections. They are fed by an 11kV ring main from an EDF intake substation.
The LV panels have air circuit-breaker (ACB) incomers and fused combination switches (FCSs), ranging from 100A to 630A, controlling outgoing circuits. Eaton is one of the few companies offering both circuit-breaker and fuse technology.
Metering is provided on the incomers and all outgoing feeds, to satisfy Building Regulation L2. Power factor correction is also included. There will be connections to a BMS system. Fused distribution boards supply local power in the substation enclosure; in some cases these are incorporated into the LV panel and in others they are installed alongside. All panels were assembled and witness tested at Eaton’s Reddings Lane factory in Birmingham.
The substations are in GRP enclosures which have blast-relief roof sections with guides which allow the roof section to rise and fall if there is an internal explosion. This facilitated installation of the transformers and cubicle switchboards by removing the roof section and craning them in.
The enclosures have separate access to high voltage and low voltage sections with an Expamet metal screen preventing direct access to the transformers and high voltage section from the low voltage section. The LV panels were designed by Eaton to include a 50mm fillet between the transformer housing and the main incoming section to allow the metal screen to be fixed to the panel itself, thereby making its installation easier for Eastern Contracting’s sub-contractor. Some of the enclosures also house emergency generators feeding a maintained section on the switchboard.
Colchester Garrison is being built to a five-year construction programme. Eaton’s substations form part of the initial infrastructure project, covering about 20 months. Under a separate contract, Eaton will be supplying modular panelboards for some of the buildings.
Steve Brett, Project Manager with Eastern Contracting, comments on the high level of teamwork by all the parties concerned with the electrical installation work, including Eaton. The Eaton equipment was delivered on time and its site team, under Andy Taylor, worked efficiently to ensure satisfactory completion. Eaton’s Regional Engineer, Gary Curtis, and Project Manager, Derek Shaw, maintained close contact throughout to ensure that any problems were resolved quickly and the project progressed efficiently.
Website: www.eatonelectrical.co.uk