Case studies BACK TO CASE STUDIES Hydro Generating Station - Irish Utility Company Project Summary Service: Major Overhaul Duration: 12 Weeks Background Quartzelec had the opportunity to work with a leading Irish utility company who operate across the electricity market from generation and transmission through to distribution and supply. The company currently operates 11 thermal stations, 19 windfarms, and 10 hydro stations. Working at a hydro generating station, located on the Lower River Shannon near Limerick, the station currently supplies electricity to more than 46,000 homes. The client initially reported a rotor earth fault, which when further investigated, revealed the need to remove the rotor and carryout a major overhaul. The Project Quartzelec were awarded the contract for the major overhaul of the vertical hydroelectric unit G4 generator to investigate low rotor insulation resistance. During the overhaul of the 36 pole, 10.5kV, 31MVA Siemens generator, the exciter, bearings, brackets and turbine guide pads were all removed and the bearings all passed non-destructive testing. Following rotor removal and inspection, it was agreed that the poles would need to be individually removed to clean the carbon and oil that was blown to the back of the poles during generation. The IR of the poles were measured where they found that 24 were below acceptance criteria, the lowest recorded being 31kΩ @ 500V. The poles were hand cleaned then electrical tested to confirm they were fit for service. Prior to reassembly the steel flange at the back of the poles were sealed using self levelling silicone sealant to prevent contamination ingress to the winding and the pole to pole connections were remade using new insulation. The stator was cryogenically cleaned and a number of electrical tests were performed including: IR, PI, ELCID and PD TAN DELTA which indicated that the stator core and windings were in an acceptable condition. A wedge plot was conducted and revealed a number of loose wedges which were replaced with new glass fibre wedges. The exciter was removed from site to a local workshop for cleaning and overhaul which included a commutator skim, undercut and bevel. The machine passed all electrical tests along with vibration and bearing temperature checks and has now returned to service. Both the client and Quartzelec had an excellent working relationship, working closely to required timescales and completion dates. CS73 LEARN MORE NEWS PUBLICATIONS ENEWSLETTERS VIDEOS EVENTS CASE STUDIES FILTER FILTER BY: TOGGLE DROPDOWN INDUSTRIES AUTOMOTIVE & AVIATION POWER GENERATION RENEWABLES OIL, GAS & PET-CHEM METALS, MINING & MANUFACTURE MARINE & DEFENCE UTILITIES COMMERCIAL HERITAGE BUILDINGS EDUCATION HEALTHCARE RETAIL & LEISURE LOGISTICS RESIDENTIAL RAIL LV INSTALLATION M&E LIGHTING HV INSTALLATION GENERATOR HV MAINTENANCE MACHINE DESIGN REFURBISHMENT DC MOTOR 2 POLE GENERATOR Connect with us Tweets by quartzelecltd Sign up to our latest Newsletter CLICK HERE Quartzelec Ltd, Castle Mound Way, Central Park, Rugby, Warwickshire, CV23 0WB +44 01788 512512 info@quartzelec.com Quartzelec is proud to be accredited by: Support Staff Log In Web Mail Sitemap Terms & Conditions Anti-Slavery Statement Gender Pay Gap Report Privacy Policy Cookie Policy Pension SIP COVID-19 Corporate Governance Manage your Preferences Registered in England and Wales No. 2364716 Registered office: Quartzelec Ltd, Castle Mound Way, Central Park, Rugby, CV23 0WB, United Kingdom We use cookies to improve your experience of our site. By continuing to browse the site you are agreeing to our use of cookies. CONTINUEFIND OUT MORE MENU CAREERS RESOURCES CONTACT