Report Turbine inspection WTG 15035, Groettocht 7

Report Turbine inspection WTG 15035, Groettocht 7 Report No. V662015067 17-11-2015

Contents 1 Purpose... 3 2 Abbreviations... 3 3 General information... 4 4 Wind turbine main components... 4 5 Documents... 5 6 Logbook: Overview of recent maintenance... 6 7 Logbook: Transformer... 6 8 Logbook: Notable events... 6 9 Tower and towerbase... 7 10 Yaw system... 9 11 Cabinets nacelle... 10 12 Nacelle... 11 13 Gearbox and main shaft... 12 14 Generator and coupling... 14 15 Hydraulic system nacelle... 16 16 Rotor... 17 17 Conclusion... 20 Date: 17-11-2015 Page 2 of 20

1 Purpose On behalf of Vattenfall an inspection has been executed on the wind turbine. The purpose of the inspection is to determine the technical state of the wind turbine. 2 Abbreviations ok na nav nc info okay not okay not applicable not available not checked for information purpose Items marked with ok and info show no visual irregularities. All issues which are not acceptable are marked with. Items which are will be classified in three different classes. Class Clarification Description in report Priority Low An irregularity, which is not a safety issue, and is relatively easy to solve. Low Priority High An irregularity, which is not a safety issue, and is more serious and is more time and/or money consuming to solve. High Safety Issue Issues which concern the safety of the people working in the turbine. Safe Date: 17-11-2015 Page 3 of 20

3 General information Wind turbine name: Groettocht 7 Wind turbine type: V66 1650/300KW - 690/50 R7035 Wind turbine S/N: 15035 Location: Middenmeer Hub height: 78 Total production [kwh]: 41265292 (according to display) Total hours: 5350 (according to display) Nominal power [kw]: 1650 Year of installation: 2003 Date of inspection: 10-11-2015 Inspectors: P. den Braber B. van de Braak K. van Zetten 4 Wind turbine main components Component Type Year Serial number Nacelle V66 1650/300KW - 690/50 R7035 2002 749502 41-02-66269 Gearbox Winergy PEAS 4395 2010 4831907-0020-4 Revision gearbox - - - Gearbox oil Texaco Meropa 320 2010 - Generator Weier GEN DASG 450W 2002 591913 Aux. Generator ABB M2CG 315MB 4 B3-0335-010729558 Blade 1 Vestas 32B - 35028 Blade 2 Vestas 32B - 35142 Blade 3 Vestas 32B - 35122 Date: 17-11-2015 Page 4 of 20

5 Documents Component Remark 1 Operator manual Operating manual is available at the turbine. Machine directive 2006/45/EC, 1.7.4.2 states as part of the Contents of instructions: (e) the drawings, diagrams, descriptions and explanations necessary for the use, maintenance and repair of the machinery and for checking its correct functioning; ok 2 Wiring diagram Wiring diagrams are not available at the turbine. Machine directive 2006/45/EC, 1.7.4.2 states as part of the Contents of instructions: (e) the drawings, diagrams, descriptions and explanations necessary for the use, maintenance and repair of the machinery and for checking its correct functioning; 3 Hydraulic diagram Hydraulic diagrams are not available at the turbine. Machine directive 2006/45/EC, 1.7.4.2 states as part of the Contents of instructions: (e) the drawings, diagrams, descriptions and explanations necessary for the use, maintenance and repair of the machinery and for checking its correct functioning; 4 Maintenance manual Maintenance manual is not available at the turbine. Machine directive 2006/45/EC, 1.7.4.2 states as part of the Contents of instructions: (e) the drawings, diagrams, descriptions and explanations necessary for the use, maintenance and repair of the machinery and for checking its correct functioning; 5 Logbook Logbook is available at the turbine. ok Date: 17-11-2015 Page 5 of 20

6 Logbook: Overview of recent maintenance Year Type of maintenance Date of execution Maintenance schedule Commissioning 07-2003 2003 9 E- 36 month service 18-04-2012 2012 9½ B - 6 month service 20-11-2012 10 G - 60 month service 11-04-2013 2013 10½ B - 6 month service 01-11-2013 11 M 11 year service 04-04-2014 2014 11½ B - 6 month service 28-10-2014 12 N 48 month service 15-04-2015 2015 12½ B - 6 month service no service record 7 Logbook: Transformer Date Event 21-05-2013 Transformer inspection 24-03-2014 Transformer inspection 20-03-2015 Transformer inspection 8 Logbook: Notable events Date Event 16-09-2010 Gear oil change Texaco Meropa 320 18-11-2011 Gearbox exchange 02-07-2013 Exchanged yaw plate and yaw claw 03-07-2012 Transformer replaced 10-09-2014 Plain bearing, torque-arm shaft, housing and block replaced (blade A and C), plain bearing exchanged (blade B) Date: 17-11-2015 Page 6 of 20

9 Tower and towerbase Item Remark 1 Outside Original door lock is broken. A chain is mounted at the ladder to lock the door. Low 2 Inside Oil visible at the inside of the tower, the cables, the platforms and the ladder. High 3 Towerbase HV-switch overview Info Date: 17-11-2015 Page 7 of 20

4 Towerbase cabinet overview Corrosion visible at the outside of the cabinet (1 st picture). Low 5 Miscellaneous Cable is in contact with the sharp edge of the cable support (1 st picture). Nut of the adjuster of the oscillation system is not tightened correctly. Low Date: 17-11-2015 Page 8 of 20

10 Yaw system Item Remark 1 Yaw bearing ok 2 Yaw ring teeth Yaw ring shows no irregularities. ok 3 Yaw pinions Yaw pinions show no irregularities. ok 4 Yaw gears Yaw gear at the rear at the right is polluted with oil (2 nd picture). Low Date: 17-11-2015 Page 9 of 20

11 Cabinets nacelle Item Remark 1 Controller The relays above the main contactor of the auxiliary generator are producing a small amount of dust. Low 2 Compensation Cabinet One of the capacitors is defect. The fuses of this capacitor bank were already removed by the maintenance team. High 3 Connection boxes ok Date: 17-11-2015 Page 10 of 20

12 Nacelle Item Remark 1 Nacelle overview Info 2 Frame Turbine is equipped with a welded frame. Info 3 Nacelle housing Parts of the insulation are missing or damaged. Low 4 Weather station Info 5 Miscellaneous Insulation in the cooling duct on the roof is blocking the air flow. Low Date: 17-11-2015 Page 11 of 20

13 Gearbox and main shaft Item 1 Main shaft bearings Remark Grease of the front bearing is dark and magnetic. High 2 Radiators The radiators are polluted with dust. The flexible hoses of the radiators are starting to wear. Low 3 Manifold Oil present on the plate under the manifold. High Date: 17-11-2015 Page 12 of 20

4 CCJ-unit ok 5 Gear oil system Leakage under the electrical oil pump. High 6 Hoses and pipes Minor leakage at the return hose of the electrical pump. Low 7 Torque-arms Torque-arm system has been modified. Info 8 Paint / Corrosion Some corrosion at the planetary ring of the gearbox. Low Date: 17-11-2015 Page 13 of 20

9 Brake-system overview Info 10 General leakage Leakage at the outgoing high speed shaft. High 14 Generator and coupling Item Remark 1 Coupling The composite parts of the coupling are in an acceptable condition. The bolts and washer of the connections are a bit corroded. ok Date: 17-11-2015 Page 14 of 20

2 Aux. Generator Aux. generator is not connected to the gearbox. Info 3 Paint / Corrosion Paint work of the generator is damaged and the surface is corroded. Low 4 RCC The RCC shows no visual irregularities. Info 5 Miscellaneous Cable at the rear of the generator is not mounted correctly. Low Date: 17-11-2015 Page 15 of 20

15 Hydraulic system nacelle Item Remark 1 Overview Info 2 Hoses ok 3 Leakage Minor leakage at the hydraulic rotation unit. Minor leakage on top of the reservoir of the hydraulic unit. Low 4 Corrosion ok Date: 17-11-2015 Page 16 of 20

16 Rotor Item Remark 1 Overview Minor pollution due to hydraulic leakage. Low 2 Paint / Corrosion Some corrosion at the entrance of the hub (See 16.3). Low 3 Connection spinner Connection has not been reinforced. No cracks detected in the tubes. Info 4 Hub cabinet overview The light in the hub cabinet is mounted with cable ties. Low Date: 17-11-2015 Page 17 of 20

5 Connections cylinder to the blade The clearance of the link bearings of pitch cylinders A, B and C are 0,15 [mm], 0,09 [mm] and 0,05 [mm]. The bearings look acceptable. ok 6 Connections cylinder to the hub The clearance of the slide bearings of pitch cylinders A, B and C are 1,08 [mm], 0,62 [mm] and 1,05 [mm]. The clearances of blade A and C are unacceptable according to the manual of Vestas. High 7 Hydraulics inside the hub ok Date: 17-11-2015 Page 18 of 20

8 Hydraulics outside the hub ok 9 Blade bearings Minor pollution with grease from the blade bearings. Low 10 Blade covers Three of the blade covers are defect. High 11 Blades overview Green pollution visible on the surface of the blades. Protective tape at the leading edge of the blades is damaged (arrow). High Date: 17-11-2015 Page 19 of 20

17 Conclusion The logbook shows that the turbine and the transformer have been maintained on a regular basis, according to the maintenance schedule of Vestas. The gearbox has been exchanged in 2011. There are no indications that the generator has been replaced and the transformer has been replaced in 2012. The plain bearings of the pitch system have been replaced in 2014. The protective tape on the leading edge of the blades is damaged at all three blades. The overall condition of the turbine is quite acceptable for a twelve year old turbine. There are however several issues (marked as in this report) present and it is recommended to solve these, in order to improve the condition of the turbine. D. Lagerweij 17-11-2015 TeSuCon B.V. Mercuriusweg 8 3771NC Barneveld +31610032858 dl@tesucon.nl www.tesucon.nl Date: 17-11-2015 Page 20 of 20

Report Gearbox inspection WTG 15035, groettocht 7 Report no. V662015101 18-11-2015

Contents 1. Purpose... 3 2. General Information... 3 3. Reporting setup... 4 4. Inspection results... 5 5. Summary... 17 6. Conclusion... 17 Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 2 of 17

1. Purpose On behalf of Vattenfall an inspection has been executed on the wind turbine gearbox. The purpose of the inspection is to determine the technical state of the gearbox. The visual inspection of the gearbox has been executed with a GE Everest XLG3 Videoscoop. 2. General Information Turbine Information Wind turbine name: Groettocht 7 Wind turbine type: V66 1650/300KW - 690/50 R7035 Wind turbine serial no: 15035 Location: Middenmeer Hub height: 78 Total production [kwh]: 41265292 Total hours: 5350 Nominal power [kw]: 1650 Year of installation: 2003 Date of inspection: 10-11-2015 Inspectors: P. den Braber B. van de Braak K. van Zetten Gearbox Information Gearbox type: Winergy PEAS 4395 i = 78,659 Gearbox serial number: 4831907 0020-4 Production year gearbox: 2010 Revision: - Revision number: - Oil type: Texaco Meropa 320 Date of last oil change: Gearbox exchange date Gearbox has been exchanged on 18-11-2011 Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 3 of 17

3. Reporting setup The next drawing shows a cross-section of a planetary gearbox with two linear stages with corresponding bearing positions. The drawing should be used as a reference for the bearing position only. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 4 of 17

4. Inspection results Picture 1 Picture 1 shows bearing position no. 1, the bearing of the planet carrier at rotor side. No irregularities. Picture 2 Picture 2 shows the bearing of the first planet wheel. No irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 5 of 17

Picture 3 Picture 3 shows the bearing of the second planet wheel. No irregularities. Picture 4 Picture 4 shows the bearing of the third planet wheel. No irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 6 of 17

Picture 5 Picture 5 shows bearing position no. 5, the bearing of the planet carrier at generator side. The bearing shows no irregularities. Picture 6 Picture 6 shows bearing position no. 6, the bearing of the low speed shaft at rotor side. The bearing shows no irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 7 of 17

Picture 7 Picture 7 shows bearing position no. 7, the bearing of the low speed shaft at generator side. The bearing shows no irregularities. Picture 8 Picture 8 shows bearing position no. 8, the bearing of the intermediate shaft at rotor side. The bearing shows no irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 8 of 17

Picture 9 Picture 9 shows bearing position no. 9, the bearing of the intermediate shaft at generator side. The bearing shows no irregularities. Picture 10 Picture 10 shows bearing position no. 10, the bearing of the high speed shaft at rotor side. The bearing shows no irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 9 of 17

Picture 11 Picture 11 shows the radial bearing of position no. 11, the bearing of the high speed shaft at generator side. The bearing shows no irregularities. Picture 12 Picture 12 shows bearing position no. 12, the bearing of the auxiliary high speed shaft at rotor side. The bearing shows no irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 10 of 17

Picture 13 Picture 13 shows bearing position no. 13, the bearing of the auxiliary high speed shaft at generator side. The bearing shows no irregularities. Picture 14 Picture 14 shows the active flank of the ring gear. No irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 11 of 17

Picture 15 Picture 15 shows one of the planet wheels. None of the planet wheels show irregularities. Picture 16 Picture 16 shows the active flanks of the sun pinion. No irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 12 of 17

Picture 17 Picture 17 shows the active flanks of the wheel of the low speed shaft in the linear stage. No irregularities. Picture 18 Picture 18 shows the active flanks of the pinion of the intermediate shaft in the linear stage. No irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 13 of 17

Picture 19 Picture 19 shows the active flanks of the wheel of the intermediate shaft in the linear stage. No irregularities. Picture 20 Picture 20 shows the active flanks of the pinion of the high speed shaft in the linear stage. No irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 14 of 17

Picture 21 Picture 21 shows the active flanks of the wheel of the high speed shaft in the linear stage. No irregularities. Picture 22 Picture 22 shows the active flanks of the wheel of the auxiliary high speed shaft in the linear stage. No irregularities. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 15 of 17

Picture 23 shows the oil level of the gearbox. Picture 23 Picture 24 Picture 24 shows the magnet of the gearbox. No steel particles are visible on the magnet. Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 16 of 17

5. Summary The visual inspection of the gearbox shows no signs of severe pitting, major damages or extreme wear. There are no steel particles found on the magnet. 6. Conclusion The gearbox is in an acceptable condition. Dennis Lagerweij Barneveld, 18-11-2015 TeSuCon B.V. Mercuriusweg 8 3771NC Barneveld The Netherlands Tel +31610032858 Email dl@tesucon.nl Web www.tesucon.nl Gearbox inspection Groettocht 7 WTG 15035 Date: 18-11-2015 Page 17 of 17