The document discusses maintenance of the Panauti Hydropower plant in Nepal. It provides background on the plant and describes its features. It then outlines objectives of maintenance, limitations, fault finding, and different types of maintenance including preventative, predictive, and breakdown. Specific maintenance schedules and checks are recommended for daily, weekly, and annual maintenance. Fault tree analyses are also presented to identify potential faults in the hydropower plant, turbine, and generator. Proper maintenance is determined to be crucial to maximize the life of hydropower infrastructure.

1. MAINTENANCE OF PANAUTI HYDROPOWER, NEPAL
Submitted By:
Subham Kandel
Master’s of Engineering In Mechanical Engineering
First year- First Semester
Submitted To:
Prof. Dr. Daniel Tuladhar
Department of Mechanical Engineering
Kathmandu University

2. Background
• Plant located in Kavre district at Khopasi.
• Third hydropower project to be built in Nepal, and it
was launched in 1965 AD with a 2.4 MW installed
capacity.
• The Roshi Khola, which is 35 kilometers east of
Kathmandu is the only source of power for the
hydroelectric project.
• It is a run of river scheme with small pondage.
• The 54-year-old Panauti hydropower project can
barely produce 1MW per hour at this time. The
hydropower plant is in disrepair, unable to provide the
necessary quantity of energy and has been dropping
since it started doing so 15 years ago

3. Features of Panauti Hydropower Plant
Installed Capacity 2400KW (3 units 800KW each)
Daily Pondage capacity 50,000 Cu. meters
Canal Discharge 3.2 m3/s
Length of canal 3721 meters
Effective head 60 meters
Maximum head 66 meters
Length of penstock 370 meters
Internal diameter of penstock 1.4 meters
Turbine maximum capacity 850 KW
Type of turbine Francis
Discharge at each unit 1.61 m3/s
Generation Voltage 6,300 Volts
Transmission Voltage 33,000 Volts up to Bhaktapur substation
11,000 Volts up to Sanga
Step Up Transformers 6,300/33,000 Volts (2*1500KVA)
6,300/11,000 Volts (2*650 KVA)

4. Objectives
The objectives of this case study are:
 To understand Panauti Hydropower Plant's maintenance schedule.
 To create a maintenance strategy for a small hydropower project if proper maintenance
isn't
Limitations:
The limitations of this case study are:
 The upkeep schedules created for this HPP might not be applicable to every
hydropower pant.

5. Fault Finding
For a smaller HPP like Panauti, it is also important to be cost-effective therefore before
beginning maintenance work, we must determine whether it is indeed necessary or not at this
time. Knowing when to perform maintenance is therefore crucial to avoiding unnecessary
maintenance. In an HPP, some general indicators that maintenance is required include the
following:
 Failure to start the turbine or generator
 Vibrations
 Mechanical noise
 Windings overheating
 Bearing Overheating
 Oil leakage
 Generator Failure

6. MAINTENANCE OF A SMALL HPP
"Maintenance is the sum of all technical and administrative procedures including supervision actions, intended
to retain an object in or restore it to a state in which it can perform a specified function," according to the British
Standard Glossary of Terms. Maintenance is available in two forms
 Preventative Maintenance
 Breakdown Maintenance
 Preventive, predictive and routine maintenance are all included in planned hydropower maintenance.
Including opportunistic, breakdown and corrective maintenance in unplanned hydropower maintenance.
Any hydroelectric plant needs to be maintained regularly. There are numerous parts to a hydropower plant.
Here the upkeep of the power plant is the key concern.
 Turbine
 Shaft
 Bearings
 Generator
 Transformer

7. Maintenance Methodology
Step 1: Diagnosis
Step 2: Definition
of Objective
Step 3: Key Blocks
of Activities
Step 4: Exploration
of O&M
contractual Models
Step 5: Human
Resource
Step 6: Estimation
of Cost
Step 7: Validation
of Strategy
Step 8:
Implementation of
Strategy

8. Preventive Maintenance:
 Planned, regular or scheduled maintenance is known as preventive maintenance.
 By performing periodic and efficient maintenance processes, preventive maintenance
aims to "prevent" issues or failure before they arise.
 It is intended to prolong equipment life and prevent any unexpected maintenance tasks.
 Preventive maintenance includes checking, replacing and fixing any equipment or
component according to a schedule and predetermined guidelines.

9. Daily maintenance:
S.No. Items/Components/Parts to be
checked
Checked for
1 Foundations Parts & expansion joints  Any leaks in expansion joints, spiral casing manholes
or draft tube manholes.
2 Turbine guide bearing  Oil Level
 To check that the temperature of oil and guide
bearing are within limit.
 Check cooling water system and oil coolers.
 To check oil leakage from bearing housing.
3 Governing system  Any leakage from Governor Servomotor and its
piping system.
 Guide vane link breakage
4 Transformers  Check any unusual sparks generations.

10. Weekly maintenance:
S.No. Items/Components/
Parts to be checked
Check for
1 All the bearings • Oil Levels of all the bearings
2 Coupling flanges • Check working of shaft at coupling
flange.
3 Greasing of guide
vanes and
servomotor
• Grease in grease container
• Leakage of grease from the parts
4 Oil of OPU • Checking physically oil of OPU of the
running machine.

11. Annual Maintenance:
S.No. Items/Components/Parts
to be checked
Checked for
1 Water Path Parts (where
water flows)
 The water path's condition is examined to counteract
the impacts of cavitation and wear.
 Spiral casing, draft tube, and penstock painting.
 Conditions of distributor for wear and tear.
2 Runner  The state of the runner hubs, crown, shroud, blades, or
buckets' outside surfaces. Grinding and welding are to
be used to repair the damages caused by cavitation and
wear. It must be assured that the blades' hydraulic
profile is not altered.

12. Predictive maintenance:
 In order to do the necessary maintenance to extend the service life of the equipment, predictive
maintenance looks for changes in the physical condition of the equipment (signs of failure).
 After visiting the Panauti Hydropower Project, we discovered that some of the equipment needed to be
fixed or maintained.
 Governor oil should be lubricated if found black and if the level is low, it should be maintained at high.
 Bearing grease should be changed otherwise it might get into failure phase.
 Time to time repairment should be done in carbon brush, holders and slip rings in the time of spark
generation.
 Temperature of transformer windings should be checked if not might occur certain changes or
breakdown in windings.

13. Condition based predictive maintenance:
Condition based predictive maintenance depends on continuous or periodic condition
monitoring equipment to detect the signs of failures
 Around 6 to 8 months, dust must be cleaned from the runner and maintained rust free.
 Bearing grease should be changed in 7 days or might be in 30 days.

14. Breakdown maintenance
Repairing a breakdown is an emergency. Only after equipment failure is a repair attempted.
Maintenance is deemed successful if the machine can operate at a minimally acceptable level. This
maintenance management strategy is both expensive and ineffectual. High maintenance expenses are
mostly caused by two reasons associated with breakdown maintenance:
 Poor planning
 Incomplete repair
There must be breakdown maintenance in any organization. It is crucial to a business since even a
slight breakdown can cause significant losses. A minor malfunction in a hydroelectric facility might
result in severe power shortages. In an HPP, breakdown can result from both inadequate planning and
unfinished repairs.

15. Causes of Breakdown HPP
S.N Item Cause of Breakdown/ Failure
1 Runner  Sediment Erosion And Cavitation
2 Penstock  Due to water Pressure
 Absence of Surge Tank
3 Bearings  Lack of Oil
4 Governor  Failure of Bearing
 Leakage
5 Guide Vanes and
Stay Vanes
 Soil Erosion
 Leakage
 Improper Locking
6 Shaft  Vibration
 Failure of Bearing
 Improper coupling between generator shaft and turbine shaft

16. NON DESTRUCTIVE TESTING
Large-scale field work and lengthy downtime are required for the replacement and
maintenance of hydraulic turbines, penstocks, and other mechanical components. It would
be advantageous to obtain a more precise life estimation for this power producing
equipment in order to lower the cost related to unexpected downtime. Several NDT
methods that can be applied in a HPP include:
 Visual Inspection:
 Ultrasonic Testing:
 Magnetic Particle Test:

17. Fault Tree Analysis of Hydropower Plant
Hydropower
plant failure
Disable Turbine
Spiral Casig
Cloggiing
Faulty Guide
Vane
Malfunction of
Generator
Control System
Malfunction
Rotor Failure
Transmission
System Unable to
deliver Power
Transformer
Failure
Switch
Equipment
Failure
Transmission
Equipment
Failure

18. Fault Tree Analysis of Turbine
Disable Turbine
Spiral Case
Clogging
Faulty Guide
Vane
Faulty
Governer
Broken Guide
Vane Key
Hydraulic
System Failure
Excessive Shaft
Vibration
Broken Linkage
Between Shaft
& Runner
Faulty Shaft
Bearing
Faulty
Lubrication
System
Pump Failed Motor Damaged
Power
Interruption
Faulty
Component
Runner
Jammed

19. Fault Tree Analysis of Generator
Generator
Control
System
Failure
Rotor Failure
Rotor Rim
Failure
Ventilation
Fans Failure
Rotor Poles
Failure
Coil
Connector
Failure
Coil Internal
Short circuit
Bearing
Failure
Loosening of
Break shoe
Mechanical
Failure
Stator Failure
Stator Frame
Failure
Stator Coil
Failure
Stator Core
Failure

20. CONCLUSION
 Maintenance and repair play a crucial role in the life of Hydropower.
 Various faults and there causes were carefully identified.
 Fault Tree Analysis of Hydropower was analyzed.
 Daily, Weekly & Monthly maintenance schedule was prepared.