standards / manuals / guidelines for small hydro development - AHEC

• While working on the breaker, its operating mechanism should be de-energized suchas discharging spring, releasing air pressure etc.• Transformer should be discharged and grounded from all sides (windings). Neutralgrounding of the transformer should not be treated as grounding.• Current transformer secondary should never to be left open circuited.• After cutting out capacitor bank, it should be allowed to discharge through dischargePT for about 10 minutes. The bank should be grounded with hot stick beforecommencing the work.• ASKAREL compound used in capacitor bank as a dielectric is very toxic and harmful.Hence, should be handled with great care.• Apparatus, frame work and other non-current carrying metal parts associated withpower system are to be effectively grounded.• Lighting arresters shall be grounded independently.• Isolating switches provided for Generators and synchronous condensers and otherrotating machines should never be opened when connected to any voltage source evenwhen the machine is carrying no load.• The areas should be cordoned off indicating location of work on the particularequipment.• Use of safety tags must be ensured while allowing shut down for maintenance onsome part/ equipment.6.0 GUIDELINES FOR DOCUMENTATIONDocumentationDocumentation at all levels of work done is necessity for any references and analysisof data/information in future as and when required.Roll of operation staff is very important in registering all valid information operatingparameters such as temperature, vibrations pressure, generation, voltage current etc. in theoperation log books and shift registers.Every event should clearly mention frequency, voltage, MVAR, MW, MWH at theinstant with other necessary data e.g. alarms, annunciations temperatures, forebaylevels/reservoir levels, inflows etc. as may be necessary from case to case.Any tripping event should be clearly noted with relevant details, such as relayoperation details, disturbance recorders and event logger print outs. Restoration activitiesafter every tripping should be reported with details of preventive action taken or to be takenbased on certain conditions. This information should be presented in prescribed format,should be checked on daily basis by Engineer concerned who will check and authenticate thesame for future use.For maintenance also similar registers are maintained giving details of maintenanceactivities at different frequencies such as daily, monthly, annual etc. or break downmaintenance.AHEC/MNRE/SHP Standards/ E&M Works – Guidelines for Operation and Maintenance of Small Hydropower Station 78