The generator was removed from site and taken back to Rotamec’s in-house workshop
UK-based hydropower producer River Power Ltd engaged the services of Rotamec to repair a generator at one of its small hydropower facilities.
Located in Launceston, Cornwall, the hydropower facility features a four jet Pelton turbine fitted to a 355kW generator. Part of a private estate, at maximum capacity the turbine and generator can output up to £2000 worth of power every day. Originally commissioned in 2015, during winter 2019 it became clear that the generator had experienced a breakdown.
“With the infrastructure located underground, this was a very unusual failure,” explains James Willder, Managing Director at River Power. “What was clear was that the insulation on the generator windings had been compromised. Inspection of the generator showed that damage was consistent with a foreign body inside the generator casing itself, but nothing could be found that was missing or loose. Another scenario was that the damage was caused by lightning strikes, which can cause power spikes in cables.
“While the investigation regarding the failure was inconclusive, it was imperative to fix the issue during a time of high output, so, after exploring a number of options, we decided that Rotamec was the best option.”
Engineering support services provider Rotomec says it was chosen for the role for its speed of response and turnaround. “We operate several centres nationwide, including a branch in Exeter, which meant we could offer localised support as soon as we had customer approval to carry out an on-site inspection,” explained Managing Director, Simon Brooks. “Once we had assessed the installation, it was clear a generator rewind was required.”
The generator was removed from site and taken back to Rotamec’s in-house workshop. There it was stripped, rewound and refurbished. New bearings and sensors were also installed since the generator had already been removed. Rotamec engineers then managed the reinstallation of the generator back at site after testing. All work was completed within three weeks over the Christmas period.