On Standby for any mission critical challenge

It’s been an eventful 12 months since last year’s acquisition of Thistle Generators by rival firm Dieselec.  The resulting company, specialist generator supplier Dieselec Thistle, has not only expanded into a brand new head office on a 6.3 acre site in Glasgow, it has also established new office and workshop premises in London and a new depot in Dartford.  Along the way, it has become Scotland’s largest distributor of F G Wilson generator sets and one of the UK’s leading standby diesel generator specialists.

Comments Dieselec Thistle’s managing director, Paul Moore: “The merger between the two companies has given us the capability to answer any brief and it also means that we have the knowledge and experience in-house to recommend best-fit solutions to clients and carry out even the most challenging of installation, testing or commissioning projects.”

A Powerful Requirement

It’s an expertise that was in evidence for the company’s largest project to date: an order worth more than £3 million to provide four standby generators to protect a data centre in the heart of London’s financial district from any business interruption due to mains failure.

“Data centres store huge amounts of very valuable and sensitive information” explains Pedro Araujo, solutions director with Dieselec Thistle. “They require extreme resilience in their power infrastructure because if they lose power they can lose £millions in minutes so they’re quite happy to spend £3-4 million to ensure this doesn’t happen.

“They also require far higher levels of power than most comparable buildings,” he continues, “often having power densities more than 100 times that of a similar-sized office building. Much of the power is required to run the cooling plant which is essential to prevent the computer systems from overheating.”

A Testing Brief

Dieselec Thistle assembled the four generators and, working closely with main contractor, Skanska Rashleigh Weatherfoil (SRW), the company then subjected them to a continuous 48-hour load test at the company’s Glasgow HQ.

Conducted over a period of four days, the test required each generator to be run at full load for a continuous eight hours while its performance was monitored and recorded. Once each generator had been tested individually, the four units were then synchronised and run together for another eight hours to deliver a consistent 6mVa of power (N+1).

Pedro explains: “This rigorous test procedure was essential to demonstrate that the generators will be capable of delivering consistent, reliable power to maintain the servers and ancillary equipment once installed in their central London location.

Each generating set comprises an 11kV Leroy Somer alternator driven by a 16 cylinder Perkins diesel engine. The test also required substantial temporary equipment, however,  including a system of silencers and exhaust flues, 6mVA of reactive load banks to simulate the working load, neutral earth resistors and a five-section 11kV containerised synchronised switchboard built especially for the test.

Pedro continues: “We also bought and assembled four slave radiators, each made up of a pair of electrically-driven fans, to replicate the remote cooling system already in place on the roof of the data centre. This is because the existing cooling towers at the data centre will remain in place so we had to provide an equivalent system for the live load test.”

Logistical Challenges

After successfully completing the load test, the next step was to dismantle the equipment and deliver the generators to London for installation in the data centre.

The congested location and lack of access to the city centre site made for some logistical challenges for this element of the project. The standby generators are housed in a third-level basement car park adjacent to the building and the only way of getting them in and out was to dig through from the surface.

“We had to install the four new generators via the same route” explains Pedro. “Because the new generators are 6.5m long, we had to dismantle them into their four basic components: engine, alternator, base-frame and heat exchanger. Using a specially built mobile lifting frame and pulley, each generator was then manoeuvred over the hole, lowered into the plant room and re-assembled in situ.”

Mission Critical Expertise

Now completed, the project saw Dieselec Thistle deliver a successful outcome while the data centre remained operational and the company will continue to work with the end-user throughout a 25-year maintenance contract.

It is one of a number of ‘mission critical’ projects that Dieselec Thistle has been involved in as it continues to install, test, commission and maintain standby power for all kinds of end users.  For example, The company has recently supplied a 350kVA generator that will provide back-up power for the surface water pumps at Gatwick airport, which are used to ensure that any excess water is drained off the runway into on-site ponds. Designed to start immediately in the event of a mains power failure, the generator will ensure that business critical operation of the pump systems continues without interruption to avoid any potential disruption to airport services.

Meanwhile in East London, the company is also responsible for the supply and commissioning of a 200kVA generator for the Media Centre in the Olympic Village. With an estimated audience of four billion people, an uninterrupted power supply is essential for consistent live coverage of the 2012 Olympics from London.

Cutting Edge

To ensure that the company can supply the best, most advanced equipment, Dieselec Thistle has recently upgraded its 26-200 kVA range of generators to the FG Wilson Lean 2 range, which offers greater commonality of parts across different models making it quicker and easier to source and fit replacement parts. The 220kVA -275kVA range offered by the company will also be FG Wilson Lean 2 models from January 2012, too.


“These new models provide a streamlined package designed to offer more homogenous performance, parts and operation across the range,” adds Paul Moore, “and they are just one indication of our commitment to helping customers adapt their standby power provision as needs change, always providing the most advanced and reliable solution.”