1. Yards Creek Rotor Poles
Asia-Pacific Partnership on
Clean Development and Climate
Yards Creek Rotor Poles
Asia Pacific Partnership United States of America Power Generation Task Force August 13 – 17, 2007
J.J. Geuther

2. Project Details
Replacement of all amortisseur bars—poles must be removed and clamping heads removed.
Refurbishment of pole windings—asbestos turn insulation removal; new groundwall insulation.
Modification of pole clamping heads for reduction of stresses at step in amortisseur bars.
New pole keys.
Specialized tooling for pole rework.
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3. Project Details All 30 poles were removed and refurbished.
National Electric Coil (NEC) handled the insulation removal and pole refurbishment.
Millwrights under FE supervision removed, prepared for transport and re-installed the poles
Project was completed in 49 days working two hour shifts, 7 days/week.
All poles had to be removed via the gantry crane—up through the powerhouse roof.
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4. Project Details
Additional challenges included key removal and rigging of poles.
Two poles were worked on simultaneously from opposite sides of the rotor. Only one could be removed at a time due to crane constraints.
The remote control of the gantry crane was critical for the close tolerance work.
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5. Project Details
Early delivery of poles to the repair shop was critical.
It was decided to perform work without removal of the rotor to expedite pole removal.
Other work items were identified.
Microsoft Project was used for project planning.
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6. Concurrent Work Unit No. 1: Unit No. 3: Unit No. 2:
Inspection of M-G and P-T
Governor Unloader Modification
Unit No. 3:
Governor Oil Pump Unloader Modification
Unit No. 2:
Inspection of P-T
Replacement of Wicket Gate Stem Packing
Thrust Bearing Oil Cooler Replacement.
230kv GCB Control Wiring Replacement
Lower Guide Bearing Oil Cooler Inspection
Equalizing Line Inspection
Installation of Air Gap Instrumentation
Stator Cleaning and Corona Repair
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7. Concurrent Work Common Plant Items:
Dewatered Inspection of Penstock and Tunnel
Upper Reservoir Intake Inspection
Replacement of Spherical Valve Bypass Line Guard Valves
Replacement of 6” Nozzles on Penstock Upstream of Spherical Valve
Modification of Tailrace Trashracks
Penstock Rocker Repair
Penstock Expansion Joint Repairs
230kv Phase Reversal Switch Maintenance
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8. Removal of Rotor Poles Removal of Rotor Pole Rotor in Place
Outdoor Gantry Crane
Close Tolerances
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9. Pole Removal Rotor Rim With Poles Removed
Damage Pole Iron—2 Broken Amortisseur Bars
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10. Damage Pole Iron Damaged Pole #20 (2002) 2 Broken Amortisseur Bars
Damper Bars Unsupported in Clamping Heads
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11. Cracked Damper Bar Removal of Rotor Pole Rotor in Place 11
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12. Winding at Removal
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13. Amortisseur Bars Amortisseur Bars Following Removal
Crack in High Stress Area of Amortisseur Bar
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14. Stator Corona System
Corona Paint Restored
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15. What Can Be Done Better
Amortisseur series connection hardware difficult to install.
Handling and laydown of rotor poles.
Access through powerhouse roof.
Safety and access to stator improved by new decking.
Early delivery of replacement keys, amortisseur bars, shorting rings, etc.
Incentive for Contractor performance on critical path.
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16. What Can Be Done Better Item #28 Hardware Modification
Expedite Installation
Improved Quality Control
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