standards / manuals / guidelines for small hydro development - AHEC

• Check insulation of vapour seal also and replace, if found damaged• Check condition of housing, pivot points of thrust bearing.• Check all pressure gauges, level indicator.• Check all RTDs & TSDs- Maintenance of Air Coolers• Clean inside and outside of air cooler tubes• Check for any tube leakage by pressurizing to a pressure slightly more than max.expected working pressure• If more than 10% tubes are leaking change full set of tubes otherwise change onlyleaking tubes• After repair paint the body of coolers.- Maintenance of Oil Coolers• Clean inside and outside of cooling tubes• Check for any tube leakage by pressurizing to a pressure slightly more thanmaximum expected working• Replace full set of tubes if more than 10% of total tubes are leaking.- Maintenance of H.S. Lub system• Inspect bearing and grease, if necessary• Check the condition of hoses, if necessary replace• Check for any leakages and take remedial measures.• Check pressure gauges etc.- Maintenance of Flow relays, visual flow indicators and flow meter:• Inspect, clean water passages remove silt.• All defective meters are to be replace.- Braking and jacking system:• Check brake units and clean inside outside of the unit• Change seals• Carry out hydraulic test• Clean the filters, bowl of lubricator• Check brake track, tighten dog clamps• Check working of brake limit switches.• Replace brake lining- General checks• Check condition of current carrying leads.• Check all water & oil valves for their proper working• Check general operational healthiness of all auxiliaries• Check proper working of overspeed device.4.3 PREVENTIVE MAINTENANCE OF POWER TRANSFORMERSThe maintenance of transformer is an ongoing process and stress should be on preventivemaintenance rather than acting when a fault occurs. A schedule of maintenance activities is drawnand tabulated below. This is applicable to Main, Auxiliary, stator & distribution transformers.AHEC/MNRE/SHP Standards/ E&M Works – Guidelines for Operation and Maintenance of Small Hydropower Station 43