November/December 2019

n MOTORS Speedy Atex motor swap avoids emergency at London hospital L ondon’s Royal Free Hospital operates a 4.6MW CHP (combined heat and power) plant, based on an efficient gas turbine, that produces 36GWh of electricity, and a similar amount of heat, every year. The heat is converted in high-grade steam and used to provide heating, hot water and chilled water for the hospital. This energy strategy saves the hospital £13.7m every year and reduces its carbon emissions by 18%, resulting in a carbon footprint of around 4,500 tonnes per year. Surplus energy from the plant is supplied to the local council which uses it to heat up to 1,500 homes. Any downtime at the CHP plant threatens supplies to these homes and the hospital, as well as costing it £6,500 in daily penalty fees. So when a 315kW motor failed in the plant, it needed to be repaired or replaced as soon as possible. Because the motor was installed alongside the gas turbine, the replacement needed to be Ex-rated. The hospital called in Wilson Fan Pumps and Motors Group, based in South London, which supplies, fits and maintains electric equipment for the site. Wilson dispatched electrical engineers to investigate the problem. “Motors of that size are usually doing critical work,” explains Wilson’s sales manager, Zac Brown. “Yet they are too large for many operators to hold spares and, similarly, most stockists will not keep them on-the-shelf.” The first thing the company’s engineers did was assess whether in situ repairs would be possible but, because the motor was located is a purpose-built housing, that option was quickly discounted. So a replacement motor had to be found. “When the news came back from site that we needed to find an Atex Zone 2 Exn A IIC T3 machine, we knew the odds were against us,” Brown recalls. A quick check of the nameplate identified the manufacturer, who was called, and supply options discussed. But no suitable motor was available, even from distant distributors, and manufacturing a replacement would take a long time. “We were looking at a 12-week lead time, which was just not acceptable,” says Brown. “We had a serious situation at the hospital, and we had to explore other avenues.” Wilson contacted Worcestershire-based TEC Electric Motors, which claims to have the UK’s largest stock of electric motors, drives and gearboxes, and was most likely to have a suitable replacement. Fortunately, TEC did have the right motor in stock. Some minor modifications were needed, and work started on these immediately. Meanwhile, Wilson’s team organised the specialist lifting gear and scaffolding needed to remove the failed motor and to ensure that everything was ready for the delivery of the new motor. Engineers were on-hand when the motor arrived on site, ready to install, laser-align, test and commission it. The total time taken to source, fit, test and commission the motor was less than 24 hours, and the vital CHP plant was able to resume its operations with the minimum of costly, disruptive downtime. n When a critical 315kW Atex motor failed at a major London hospital, the race was on to repair or replace it. The motor was part of a vital CHP plant that supplies heat and power to the hospital and nearby homes, but it would take 12 weeks to build and deliver a replacement. What could be done? When the replacement motor arrived at the hospital, engineers were ready and waiting to install and align it (as shown above). The replacement Atex-rated motor for the CHP plant (right) was sourced, modified, delivered and fitted within 24 hours, minimising costly downtime. Tel: 01284 388 033 sales@ete.co.uk www.ete.co.uk Eastern Transformers & Equipment Ltd ...In complete control of power • ETE are now cer琀昀ed to design and manufacture UL Listed transformers • Designed to UL 5085 - 1 and UL 5085 - 2 standards • 25VA to 5kVA 1ph • Manufactured in the UK • Fast turnaround • Custom - built to your speci昀c requirements