1. Seneca Overview & Generator Rewind
Asia-Pacific Partnership on
Clean Development and Climate
Seneca Overview & Generator Rewind
Asia Pacific Partnership United States of America Power Generation Task Force August 13 – 17, 2007
Ron Kovach/Tom Groff

2. Seneca Overview
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3. Seneca – View of Upper Reservoir
1/2 mi. dia.
60 ft deep
800 ft above plant
asphalt lined
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4. Seneca – View of Plant & Lower Reservoir
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5. Seneca Plant Pumped Storage Facility
3 Units – Unit 1 218MW; Unit MW; Unit 3 30 MW
Role of Plant
Provide generation, regulation and spinning reserve during on-peak hours
Provide an energy sink off-peak (11 P.M. – 7 A.M.) to allow Fossil and Nuclear plants to remain more fully loaded (Base-Load Strategy)
Black Start capability
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6. Priorities Safety Environmental and Regulatory Compliance Reliability
Federal Energy Regulatory Commission (FERC)
Pennsylvania Department of Environmental Protection (PADEP)
Reliability
Cost effective operations
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7. Staffing On-site staffing Corporate Support Other
6 Operators / 3 Maintenance
1 Administrative
2 Management
Corporate Support
Engineering
Environmental
Administrative IT
Legal
Other
Contract labor services
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8. View of Motor/Generator
1. Exciter
2. Upper Guide Bearing
3. Motor/Generator Rotor
4. Motor/Generator Stator
5. Thrust and Guide Bearing
6. Main Shaft
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9. View of Pump/Turbine 9 9. Lower Guide Bearing
7. Wicket Gate Servomotor
8. Wicket Gate Operating Ring
10. Turbine Head Cover
17. Spherical Valve
12. Wicket Gate
11. Stay Ring
13. Runner
14. Spiral Case
15. Draft Tube Cone
16. Draft Tube Man Door
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10. Typical Spherical Valve (also called High Head Guard Valve)
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11. Equipment Suppliers Newport News Pump-turbines – Voith Runners
L & S Governors
Westinghouse motor – generators / National Electric coil rewinds
Westinghouse voltage regulators
BLH spherical valves
ABB 230kv GCB’s
Allis Chalmers 220MVA Step-up transformers
Pascor Atlantic 230kv Phase reversal switches
400kva Emergency generator
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12. Significant Projects Pump-Turbine Upgrades Motor-generator rewinds
Unit No. 1 – 1992
Unit No. 2 – 1991
Motor-generator rewinds
Unit No. 1 – 1971, 1985, 2006
Unit No. 2 – 1977, 1981, 2007
Unit No. 3 – original
Upper Reservoir side slope paving – 2000
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13. Generating Operation 1 2 3 1 2 3 Upper Reservoir #1 218 MW #2 195 MW
21' diameter pipe, 3200' long 1 2 3
Motor/Generator
Pump/Turbine 1 2 3
#3 generates to Allegheny River only
#1 generates to Lower Reservoir only
#2 can generate
to Lower Res or river
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14. Penstock Rendering Unit No. 1 – 218MW Unit No. 2 – 195MW
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15. Pumping Operation 1 2 3 1 2 3 Upper Reservoir #1 220 MW #2 220 MW
#3 Does not pump - used for starting #1 & #2 1 2 3 1 2 3
Units 1 & 2 draw water from the Lower Reservoir
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16. Operation Upgraded Pump-Turbines – Efficiency Gain
3% Pumping
5 % Generating
700,000 + MWH Annual Generation
Equivalent Forced Outage Rate (EFOR) < 2%
High starting reliability
8 minute generate starts
30 minute pump starts
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17. (Black Start Reserve)
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18. Seneca: Generator Rewind18

19. Generator Rewind
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20. Decision to Rewind Last rewind occurred 20 years ago Tax Credit
Upgrade (8MW)
Extra copper – 7%
Coil replacement
End-of-life
Proactive
Partial Discharge (PD) / Corona
Rotor Pole refurbishment
Asbestos removal
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21. Generator Rewind Unit #1 – Core Iron Continuous Restack
Unit #2 – Core Repairs
Loop test criteria max
10°C Hot Spots
Repair techniques
Thin mica sheets, between laminations
Grind and electro-mechanical etching
New Air Coolers - #1 & #2
Crane
Engineered lift
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22. Stator Lifting Beams Bolted to Stator Pinned to (2) crane hooks
Stator weighs 232 tons
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23. Stator Lift over Unit #3
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24. W Nameplate Info
336 Coils
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25. Loop Test Cables 16x3 Turns 2400 Volts 300/Loop Amps
Stator Iron in 3 Sections
IR Camera to look for hot spots
10°C or less acceptance criteria
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26. Coil Wedges Top view of slot wedges with ripple springs behind 26
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27. Brazing Brazing done using an Induction Machine 264 Series Joints
50 Jumper Joints
50 Phase Joints
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28. ( ) ( ) ( ) ( ) = 60hz Pole Keys 2 per Pole 225 RPM 32 Poles
225 Revolutions
1 Minute (
1 Minute
60 Seconds ) (
32 Poles
1 Revolution ) (
1 Cycle
2 Poles ) ( ) =
60hz
(Cycles/second)
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29. Pole Shipment Fixture
Bottom fixture rounded to allow horizontal placement
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30. Thrust Bearing Shoes Thrust Bearing Shoes in place
Oil supply hoses installed
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31. Wear Pattern on Thrust Bearing Shoes
Removed from Unit #1
Units No. 1 and No. 2
12 shoes each
Unit No. 3
8 shoes
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