Report Inspection of wind turbine Report no. : 7273-02 Owner : Højstrup Vind KS Manufacture : Vestas Type : V44-600 kw Serial number : 2418 Site : Højstrupvej 42, 9750 Østervrå Location, UTM 32 : 579700, 6359350 In service date : 23 December 1996 Inspected date : 21 May 2013 Task : Inspection on sale Requested by : Niels Jørgen Lunden Ole Andersen 25. may 2013
Conclusion No. Shall be performed To follow up Recommen dations 1 Maximum temperatures of gear oil of 80 C and gear bearing 96 C is above normal for this gearbox type. The maximum temperature in the gearbox should be reset and kept under observation. The thermostat in the gearbox and the cooling system should be checked. X 2 When the blades are dismount and lying on the ground, it is recommended to inspect the blades carefully and correct any damages. X 3 The gear suspensions must be kept under observation. X 4 The sliding surfaces on yaw system must be lubricated. X 5 Brake disc and brake pads must be cleaned and the leak found X and sealed. 6 A crack in the nacelle roof must be repaired. X 7 The crack in the bracket at the pitch cylinder must be welded. X 8 It is recommended to exchange the relay for the hydraulic pump. X 9 The cable on the crane must be shortened or replaced. X The condition of the wind turbine was found fair considering the life time and many operation hours. In total 9 remarks have been listed. Ole Andersen 25. may 2013 Report no. 7273-02 2
Introduction This report is prepared on the basis of a visual inspection of the wind turbine, readings from the control system and the service reports. The conclusions are taken from the known experience with the components at the time of the inspection. The inspection is carried out after best practise and there is no guarantee that all faults on the wind turbine are found. The wind turbine shall be dismantled and erected on a new site. The nacelle and the blades will be taken to a work shop, where defects can be repaired. The conclusions and recommendations in the report are taking this into account. The wind turbine was inspected on May 21 th, 2013. The weather was cloudy with wind speeds of 2 m/s increasing to 3 m/s, and ambient temperature of around 15 C. Name plate Vestas Type V44 690 V 50 Hz 600 kw No. 2418 Year 1996 Control system Main switch board Vestas Type VMP 600 kw 690 V 50 Hz Voltage 690 V +6/-10 % Frequency 50 Hz +1/-3 Hz Current 517 A Protection class IP 54 Max short circuit current 14 ka Serial no. 34545 Report no. 7273-02 3
The following was read out from the display: 1. Actual power : -0,9 kw Generator : 728 rpm Rotor : 13,9 rpm Wind speed 2,3 m/s Pitch : 2,0 1A. Max. power (1 sec. average) : 626,8 kw Max. wind speed : 24,2 m/s Max. rotor : 30,8 rpm Reset : 12-Okt-30 1B. Turbine ID : 2418 Programme version : 1,14 03-sep-18 2. Generator 0 : -27.589 kwh -22.581 kvarh Generator 1 : 18.901.032 kwh -1.085.506 kvarh Production : 18.873.444 kwh -1.108.087 kvarh Reset : 96-Dec-23 96-Dec-23 3. Total : 143.830 hours Line OK : 143.349 hours Turbine OK : 142.918 hours Run : 142.246 hours Generator 1 : 95.336 hours Ambient : 141.733 hours Line : 143.662 hours Yawing : 7.432 hours Service : 226 hours Available : 143.436 hours Reset : 96-Dec-23 4. Availability (average of the last 12 months) : 100,0 % 5. Power : -0,9 kw cos : 0,81 Frequency : 49,98 Hz Voltage : 397-398-397 V Current : 1-1-1 A Report no. 7273-02 4
6. Temperatures Actual Maximum 1 Ambient : 15 28 C 2 Gear oil : 31 80 C 3 Generator : 23 119 C 4 Hydraulic oil : 26 55 C 5 Ground control : 29 44 C 6 Gear bearing : 52 96 C 7 Nacelle : 21 40 C Reset : 11-Nov-25 The total availability calculated as Turbine OK / Line OK is: 99,70 %, which is very good. Maximum temperatures of gear oil of 80 C and gear bearing 96 C is above normal for this gearbox type. The lubricant type, the bearing types and the design of the lubrication system will have influence on the level for the maximum bearing temperatures. It is recommended that the gear oil temperature is kept at maximum 60 C for mineral oils and not over 70 C for synthetic oils. Ageing of the oil happens much more rapid at increased temperatures. Furthermore higher oil temperatures causes the oil film thickness to decrease, this will have a negative effect on the life expectancy of both bearings and gears. The maximum temperature in the gearbox should be reset and kept under observation. The thermostat in the gearbox and the cooling system should be checked. Maximum temperature in generator of 119 C is normal. Alarm list is not available. Foundation The foundation was inspected for cracks in concrete, connections between concrete and iron parts, sealing, etc. The foundation consists of an armoured concrete footplate with a cast in steel part, on which the tower is connected with a flange connection. The foundation is filled with concrete until app. 200 mm below the flange. The surface of the foundation inside the tower was found dry, and no abnormal cracks were found. Report no. 7273-02 5
Tower The tower was inspected for surface treatment, bolt connections, weldings etc. Evaluation of accessibility. Ladder and safety equipment was inspected. The tower is in two parts connected in a flange connection. No comments were found to the connection. The safety wire in the tower is an 8 mm stainless steel wire. Blades The blades were inspected for cracks and other defects of the surface using a pair of binoculars. This method is not nearly as precise and effective compared with repelling down along the blades or inspecting the blades using a man basket and a crane or a hoist. Vestas Vestas Vestas 20,5A 20,5A 20,5A The serial numbers could not be read on the name labels on the blades. The blades are called A, B and C. Blades are mounted with blade extensions, see photo 1. The Blades seems in good condition with age taken into account, see photo 2 and 3. When the blades are dismount and lying on the ground, it is recommended to inspect the blades carefully and correct any damages. Pitch system The moving parts in the hub could not be inspected because of lack of wind. The pitch operation was found to operate smooth and precise. Main shaft and main bearings The main shaft was inspected for rust, wear etc. No comments were found to the main shaft. Report no. 7273-02 6
Almost no leak grease was seen in the bins under the two main bearings, which is preferable, see photo 4. Gear box VALMET POWER TRANSMISSIONS Inc. No. 40047 Type S3GHD-506X Ratio 52,478 Oper. Power kw 660 n1 min -1 29,08 Oil 125 L JYVÄSKYLÄ, FINLAND The oil in the gearbox is Texaco Meropa 320. This is a mineral base oil used by Vestas for many years with a good result. The oil level was found in the level glass. The oil level was between the minimum and the maximum mark, see photo 5. The inspection covers were dismantled. The visible gears and bearings were inspected. Search for magnetic particles was done. The gear is a three-stage gear. The gear wheel in the first step distributes the power into two intermediate shafts. From here the forces again onto a shaft which is floating in the axial direction. In the 3rd Steps are also two gears but on the same shaft and opposite toothed. See Annex for the identification of axles teeth and bearings. Wear and indentation marks on gear mesh and wear in bearings are given in categories. See enclosure explaining these categories. The inspection covers were dismantled for inspecting of the three parallel stages. Gear mesh Photo Observation Category Category Wheel LSS 6 No abnormal wear found. K1 P0-1 shaft Pinion upper 7 Mikropitting, no abnormal wear K1 P0-1 LS IMS found. Pinion lower 8 No abnormal wear found. K1 P0-1 LS IMS Wheel upper 9 No abnormal wear found. K1 P1 LS IMS Wheel lower 10 No abnormal wear found. K1 P1 LS IMS Pinion front 11 Mikropitting, no abnormal wear K2 P1 HS IMS found. Pinion back 12 Mikropitting, no abnormal wear K2 P1 HS IMS found. Report no. 7273-02 7
Wheel HS IMS Wheel HS IMS Pinion shaft front back HSS 13 No abnormal wear found. K1 P1 14 No abnormal wear found. K1 P1 15 No abnormal wear found. K1 P1 Not all of the bearings in the gear box could be inspected through the inspection covers. Bearing Bearing type Photo Observation Category position R-lower LS 16 No signs of abnormal wear. L0-1 IMS NR-upper LS 17 No signs of abnormal wear. L0-1 IMS R-HS IMS 18 Wear stripes on rollers. L0-1 M-HS IMS 19 Light wear stripes on rollers. L0-1 Mikropitting are seen in the gearbox. But the gearbox seems in good condition with age taken into account. A magnet was swept over the bottom of the low speed part of the gearbox and no particles could be found here, see photo 20. A magnet was swept over the bottom of the hi speed part of the gearbox. Small particles could be found, see photo 21. The gearbox be kept under observation. The gearbox is equipped with an in-line oil filter mounted on the block and an off-line filter for cleaning out the very fine particles in the oil is mounted, see photo 22. The pressure was controlled and found OK. The bearings in the gearbox are one of the weakest elements in the turbine. Therefore all possible improvements should be done to get better conditions for the bearings. Cleaner oil will give longer lifetime of the bearings. There is an alarm for low level of oil in the gearbox, see photo 23. Loss of oil can happen due to defects in oil hoses, defects in gaskets, improper placement of gaskets at filter exchange etc. The covers were dismantled for inspecting gear suspensions, see photo 24. Frictional corrosion is observed and the gear suspensions should be kept under observation. Report no. 7273-02 8
Connecting shaft The connecting shaft was inspected for wear, play, cracks etc. The connecting shaft is a cardan shaft. The bearings are lubricated at the service inspections. The grease will leak out from the bearings with time and spray out on the nacelle wall and right side yaw drive, see photo 25. This is normal. Generator ABB Motors Type: M2CG 400XL 4 B3 S1 AMB MAX +50 C No. 3439290 ST 20078-1 Ins cl. F/H IP 54 Volt Hz kw O/min Ampere Cos fi 690 Y 50 600 1509 567 0,88 690 Y 60 600 1810 564 0,89 A 150 A 150 Cat. code: 3GCG 402600-RXAVE007 6322/C3-6322/C3 2990kg The generator was replaced in November 2001. The terminal box on the generator was opened for inspection, see. photo 26. No comments were found. The generator is equipped with an automatic lubrication device. At the day this inspection took place the grease level was more than 50%. The greasing device is equipped with a stirrer to keep the greasing floating in the container. The device was tested and found OK. Yaw system The yaw system was inspected on sliding surfaces, clearances were measured. Gears on yaw rim were inspected. Motors 1,5 kw 2 yaw gears Yaw gear Bonfiglioli Worm stage Bonfiglioli Planetary stage The bottom sliding surfaces were found dry and rusty, see photo 28. The sliding surfaces must be lubricated. Report no. 7273-02 9
The teeth on the yaw rim and the yaw drives are well lubricated and without abnormal wear, see photo 29. Power consumption during yawing was measured to 3,4 A, which is normal for this turbine. Brake system Brake pads, callipers, hydraulic hoses and pipes were inspected. Hydraulic unit was inspected for leaks etc. Stilfreni 3 callipers The brake pads were found with sufficient lining and the brake disc was found without deep wear grooves. There were leaking oil on the brake disk and brake pads, see photo 30. Brake disc and brake pads must be cleaned and the leak found and sealed. Hydraulic system Hydraulic station Berendsen PMC All hoses were found well installed, no sign of wear on the hoses was detected. The oil level in the tank was found in the glass. No leaks to the outside were found. Nacelle The nacelle was inspected of surface treatment, bolt connections, weldings, wear on moving parts, cleanliness and accessibility. A crack in the nacelle roof was found, see photo 31. The crack must be repaired. A crack was found in the bracket at the pitch cylinder, see photo 32. The crack must be welded. The nacelle was found well cleaned. The crane was tested and function found OK. Report no. 7273-02 10
Electrical installations Cables etc. were inspected for correct mounting and wear. All connection boxes and switchboards were opened for inspection of wear, leaks, cleanliness etc.. The phase compensation plant was tested by the built in test in menu 11: Step 1 2 3 4 L1 59 58 38 38 L2 59 58 38 38 L3 59 58 39 39 All condensers in the phase compensation plant draws app. 10 A, which is normal. The cables in the tower and in the nacelle are generally well fastened and no wear was found on the cables. The relays for yawing and hydraulic pump are seen on photo 33. These three relays have many cut in and out, and the relay for the hydraulic pump is worn. It is recommended to exchange the relay when the nacelle is down in a work shop, to avoid down time from defective relays after start of operation on the new location. The cable to the crane is defect, see photo 34. The cable must be shortened or replaced. Function testing Emergency stops in nacelle were tested and found OK. Vibration switch was tested and found OK. Coupling in and out of generator could not be performed due to a lack of wind. Yawing is done smoothly and without noise. Stopping by pitching blades and activating the mechanical brake was tested and found OK. Sound level from gearbox running could not be performed due to a lack of wind. Ole Andersen 25. may 2013 Report no. 7273-02 11
Split drive gearbox S3GHD-506 Designation of shafts Upper low speed intermediate shaft ULSIMS Designations of gear mesh High speed intermediate shaft HSIMS Lower low speed intermediate shaft LLSIMS Low speed shaft LSS Wheel on ULSIMS High speed shaft HSS Pinions on HSIMS Pinion on ULSIMS Pinion on LLSIMS Wheel on LSS Wheel on LLSIMS Wheel on HSIMS Pinions on HSS Designation of bearings ULSIMS R-bearing ULSIMS NR-bearing HSIMS R-bearing R = rotor end NR = non-rotor end C = center HSIMS C-bearing HSIMS NR-bearing LSS R-bearing LLSIMS R-bearing LSS NR-bearing LLSIMS NR-bearing HSS R-bearing HSS NR-bearing
Photo 1. Blades are mounted with blade extensions. Photo 2. Blade A. The Blades seems in good condition.
Photo 3. Blade C. The Blades were in good condition. Photo 4. Almost no leak grease was seen in the bins under the two main bearings.
Photo 5. The oil level in the gearbox. Photo 6. Wheel LSS shaft
Photo 7. Pinion upper LS IMS Photo 8. Pinion lower LS IMS
Photo 9. Wheel upper LS IMS Photo 10. Wheel lower LS IMS
Photo 11. Pinion front HS IMS Photo 12. Pinion back HS IMS
Photo 13. Wheel front HS IMS Photo 14. Wheel back HS IMS
Photo 15. Pinion HSS shaft Photo 16. Bearing R-lower LS IMS
Photo 17. Bearing NR-upper LS IMS Photo 18. Bearing R-HS IMS
Photo 19. Bearing M-HS IMS Photo 20. A magnet was swept over the bottom of the low speed part of the gearbox.
Photo 21. A magnet was swept over the bottom of the high speed part of the gearbox. Photo 22. The gearbox is equipped with an off-line filter.
Photo 23. Alarm for low level of oil in the gearbox Photo 24. A gear suspension.
Photo 25. The connecting shaft is a cardan shaft. Photo 26. The terminal box on the generator.
Photo 27. The generator is equipped with an automatic lubrication device. Photo 28. The bottom sliding surfaces on the yaw system were found dry and rusty.
Photo 29. The teeth on the yaw rim and the yaw drives are well lubricated. Photo 30. There were leaking oil on the brake disk and brake pads.
Photo 31. A crack in the nacelle roof was found. Photo 32. A crack was found in the bracket at the pitch cylinder.
Photo 33. The relay for the hydraulic pump is worn. Photo 34. The cable to the crane is defect.