Turbine Maintenance Techniques Flashcards
What is “torquing”? How is it difference than tension?
Torque is a rotational forces and tensioning is a stretching force.
(Torquing is about stretching the bolt or stud by turning the nut
This pulls the shank due to the thread’s ramp angle. The, friction
between the nut and component hits a predetermined amount.)
What is “tensioning”? How is it difference than torque?
Tensioning is the force of stretching,
not rotating a nut.
(Tensioning does not turn the nut. To mount a tensioner, the full height of threads must equal the thickness of the nut above the nut. When hydraulic pressure is applied, the pulling cylinder stretches the bolt. Once the threadèd
shank is stretched, seat the nut and remove the pressure.)
What is the 10% bolt maintenance method?
Each year, tighten (torque/tension) 10% of the number of bolts, then next year move down 1 bolt number and tighten 10% more.
Regarding alignment of the wind turbine gearbox to the generator, which can be moved and which can not?
Generator can be moved
Gear box can not be moved
What is SCADA and how do wind turbines use it?
“Supervisory
Control
And
Data
Acquisition
SCADA is a control system architecture comprising computers, networked data communications and graphical user interfaces for high-level supervision of machines and processes. It also covers sensors and other devices, such as programmable logic controllers, which interface with process plant or machinery.”
Source: https://en.wikipedia.org/wiki/SCADA
What is a “Clamp on Meter” and what does it do well?
A clamp meter can measure amps, ohms of resistance, volts of current, and hertz using electricities electromagnetic fields. Breaking into the circut is not needed.
This meter measures current in volts the best.
Where do do DC circuits originate?
At the power supply
Before working on an electrical part how do you test for voltage?
1) Test your multimeter fuses by…
2) Do a Hot-Cold-Hot multimeter voltage check: Test all phases with circuit hot, then power off and test voltage of all phases, then check your meter by testing another similar circuit that is still like to rule out a blown meter.
On a 3 phase system test:
N-1
N-2
N-3
1-3
2-3
2-1
How do you do a multimeter fuse test on a Fluke 87?
Fuse Test
Dial to V
Red lead to A: beep = good fuse
Red lead to mA, Beep = good fuse
How do you re-reference the rotor blade pitch position sensor?
With the blade at the 0° position (indicated by vernier at blade root) compare with the position indicated by the pitch control system. If the deviation >0.5°, re-reference the rotor blade
What can “additional noise emissions” from a moving blade indicate?
D.U.D.E !
- Damage on the rotor blades
- Unrepaired transit damage
- Dirt accumulation
- Erosion of the blade
What is done for an external blade inspection?
Inspect the external part of the blade. In doing so, check the following:
• Blade tip
• Trailing edge
• Surface of the blade
• Lightning strikes
• Cracks
• Coating damage
• Erosion
• Cleanliness
• Blade root
- Function Test: From a safe distance and with the rotor spinning, listen for abnormal noise or vibration.
1) How do you mark a torqued bolt?
2) What colors should be used for what occasion (Red, Blue, black)?
All torqued bolts must be marked with a single line running down the side of the bolt head, across the washer and onto the clamped part, with an oil-based paint marker.
2) For installation, blue is preferable for a first torque and always use red for installation torque inspections
When inspecting bolt connections during annual maintence, the stud _______ ___ ________ through seating of the stud, but it is not normal for nuts to actually ______ __ ___ ____ from operation.
1) tension may decrease
2) rotate on the stud
Under normal conditions, the stud tension may decrease through seating of the stud, but it is not normal for nuts to actually rotate on the stud from operation.
If any nuts have misaligned paint marks, document the position and estimated degree of movement of effected studs.
During annual maintenance, It is common for the nuts to rotate __ to __ degrees beyond the earlier
torque mark
It is common for the nuts to rotate 0 to 20 degrees beyond the earlier
torque mark
What happens if you fill a component with too much grease?
What also helps when greasing bearings?
It can push the seal off.
It is better to rotate bearings while greasing.
Calculate the pressure in psi needed to torque a 5.4 square inch piston tool to 75,000 foot pounds of force on a foundation bolt.
Pascal’s Law
Pressure = Force divided by Area
PSI = 75,000 ft. Lbs. / 5.4 sq. In.
= 13,888 psi ?
Area of piston tool (size of tension tool 5x9 piston = 5.4 sq. inches
75,000 ft. pounds
Force
Name the parts of a “low profile hydraulic ratchet”. What is another name for it?
- Ratchet
- Piston
- Reaction Arm
Stealth Head
1)Try to list all the 11 parts of a yaw piston assembly from top to bolt head to bed plate
2) and torque requirement
1) Adjusting Bolt/Screw
2) Lock Nut
3) Plastic pins / Tubber plugs
4) Retaining Ring / Snap Ring (keeps from walking out)
5) Tapped / Threaded Bushing
6) Spring Pack (contains Thrust piece, Disk springs / Compression washers (arced), O-Ring on top)
7) Shim Ring (at bottom of piston_
8) Brass Piston / Piston Bushing
9) Piston O-Ring
10) Puck
11) Bed plate sleeve
100 Nm of torque + 300 degrees of angle
What is the term for when a torque spec has newton meters and degrees of rotation?
Torque and Angle
How may pistons support a GE 1.x nacelle?
12 piston assemblies
1) How many “flats” does a standard bolt head have?
2) How many degrees is each?
1) 6 flat sides
2) 1 flat corn to corner = 60degrees
2 = 120
3 = 180
4 = 240
5 = 300
6 = 360
When doing a yaw puck tensioning, what should you do before tensioning?
Inspect the pucks
What does the acronym BIM represent?
Describe what it means.
Break-In Maintenance
BIM tasks may begin after 360 operating hours post-COD and must be completed within 5 months from the completion of those 360 operational hours.
What does the acronym SA represent?
What does it mean?
Semi-Annual Maintenance
SA maintenance tasks must be performed within 7 months of previously completed SemiAnnual maintenance tasks, or within 6 months from the date that the WTGS completed 360 operational hours post-COD.
What does the acronym A represent in turbine maintenance?
Annual Maintenance
Annual Maintenance tasks must be performed within 13 months of previously completed annual maintenance tasks, or within 12 months from the date that the WTGS completed 360 operational hours post-COD.
What does the acronym BRM represent?
What does it mean?
Beyond Regular Maintenance.
This maintenance work does not fit exactly in the specified interval (e. g. once after 6 months and then annually; every 36 months etc.). Additional information is provided in the column for maintenance work.
Maintenances are typically done how many times per year?
Once
What is the tensioning target for anchor bolts on a GE 1.6 ESS?
Used: PSI = 75,000 ft. Lbs. / 5.4 sq. In. = 13,888 psi
Manual states: Base flange with anchor bolts 55 “Design Specific”
What is the torque requirement for tower flange bolts on a GE 1.6 ESS turbine?
2800for M36 60 (or 3500 for M39 65< 4500 for M42 70, 5500 for M45 75)
What is the frequency of torqueing for tower flange bolts on a GE 1.6 ESS turbine?
BIM and Annual
What is the torque requirement of a yaw friction system?
100 Nm + 300° for Yaw Friction System - Adjusting Screw M39 60
What is the lubrication requirement of the yaw bearing on a GE 1.6 ESS turbine?
Yaw bearing (manual) Fuchs Stabyl EOS E2 (or) Mobil SHC 460 WT per bearing: 1 cartridge, 400 g
What type of lubricant is used on the yaw bearing on a GE 1.6 ESS?
Fuchs Stabyl EOS E2 (or) Mobil SHC 460 WT
1) What is the lubrication requirement for the yaw ring and pinion gears?
2) What lubricant is used on the yaw ring and pinion gears?
1) Yaw Gear Ring and Driving Pinion - Annual
2) Yaw ring gear and drive pinions (manual) Fuchs Ceplattyn (black) (Manual) For each gear/pinion: approximately 1200 g
What is the torque requirement for the rotor shaft/hub connection?
2800 Nm
for Rotor shaft / Hub M36 55
(Silver bolts: 2800 Nm; Black bolts: first maintenance after 1 month (1M) 2800 Nm +60°; subsequent maintenance annually (12M): 2800 Nm)
What is the lubrication requirement of the main bearing?
Annual
What type of lubricant is used in the main bearing?
Fuchs Stabyl EOS E2
Main bearing (manual) if For cold-weather components: All manufacturers Mobil SHC 460WT
FAG Arcanol Multitop
SKF LGWM 2
Fuchs Stabyl EOS E2
all 1.6 kg
What is the torque requirement of the shrink disk?
1700 Nm
for Shrink disc M30 46
Describe the replacement requirements of the gearbox oil filter.
Break in Maintenance
Annual
and
replacement task beyond regular maintenance
What is the lubrication requirement for the generator bearings?
Break in Maintenance
&
Annual
What is the torque requirement for the pitch bearing to hub attachment?
1300 Nm
for Hub / Pitch bearing 1.x-82.5 M30 50
(Pg. 287)
What is the lubrication requirement for the pitch ring and pinion gear?
Break in Maintenance
&
Annual
for Gear Ring and Driving Pinion lubrication requirement
What is the torque requirement of the rotor blade to pitch bearing studs?
350 Nm + 120*
350 Nm + 120* + MoS2 for GE40
40.3P 350 Nm +120* + MoS2 for LM
When inspecting the padmount transformer, name one possible condition of damage.
- Moved or rotated off installed foundation block
Inspect the pad mount transformer for following discrepancies: - Doors properly secured
- Leaks
- Physical damage
- Abnormal noise
What is an approximate PSI for a pull test of the foundation bolts?
13,500 PSI
( Pascal’s Law is Force = Pressure / Area )
- PSI = 75,000 ft. Lbs. / 5.4 sq. In. = 13,888 psi
1) What is the torque requirement for tower flange bolts?
2) How often are tower flange bolts torqued?
1) 2800 Nm
For M36 (60mm) bolts
2) During break in maintenance and annually
What is the torque value of the yaw piston adjusting bolt?
100 Nm + 300°
torque & angle
1) What is the grease quantity for main bearing lubrication?
2) How often is the main bearing lubed?
1) 1.6kg (4 tubes) of Fuchs Stabyl
2) Semi annually and annually
What is the gear ratio of the LRSC wind turbine gearbox?
3:1
The GE General Electric GE 1.6 is fitted with a spur/planetary gearbox. The gearbox has 3 stages.
What might reduce the effectiveness of the gearbox oil cooler radiator?
- Moisture not removed by the desiccant filter?
- Weather / air temperature
How often is the gearbox primary filter changed?
Gearbox Oil Filter break in maintenance, Semi annually, Annually
Bonus: Gearbox Desiccant/Ventilation Filter Is replaced BRM (break in maintenance)
How many kilograms are in a tube tubes of Fuchs Stabyl?
4kg
1.6kg = 4 tubes for Fuchs Stabyl
What is the purpose of a generator alignment?
To allow precision rotation of energy to the generator and prevent wear.
How can a technician see the oil level in the gearbox?
Gearbox oil level checked at drain plug, should be able to see oil at tilt.
Open the access port?
1) What is the torque value of the hub/pitch bearing connection?
2) What is the torque value of the blade/pitch bearing connection?
1) 1300 Nm
Hub / Pitch bearing (Inside blade bolts?) = 1300 Nm on a 82m blades
2) 1300 Nm
Notes: Outside blade bolds = 1300 Nm; Torque for 40m blade = 350Nm + 120° on Pitch Bearing studs
See pg. 288
What is the lubrication quantity requirement for a pitch bearing?
1.5 tubes (550g)
Fuchs Gleitmo 585 K (1 tube = 370g)
See manual pg. 272: Pitch bearing (manual) Fuchs Gleitmo 585 K per bearing: Types:1.x-70.5/77: 350g
Types: 1.x-82.5: 550g
List the accepted types of pitch bearing grease?
Fuchs Gleitmo
What is the acceptable gearbox oil?
Castrol Optigear Synthetic
From GE Manual:
Oil type: Castrol Optigear Synthetic A 3201
Oil type: Castrol Optigear Synthetic X 320
List the accepted types of generator grease?
Klueberplex
From GE Manual (Pg. 271):
- Generator / bearing (manual) Oil type: See nameplate;
- Generator / bearing (auto greaser) Klueberplex
List the accepted types of yaw bearing grease.
Fuchs Stabyl
From GE Manual (See Pg. 270):
Yaw bearing (manual) = Fuchs Stabyl
Why is it a good procedure to roll the hub when lubing the main bearing?
Putting in too much grease can push out seal
What is the purpose of the service key?
The O - Operate Key has 3 setting:
I + Service (for general maintenance, but tower is available after work),
0 = Operate
II = Repair (broken, tower not available, logs down-time, protects crew)
List the yaw piston removal and installation procedure.
- Inspect puck’s first
Removal:
1) Loosen lock nut, Tighten tapered bushings to relieve pressure on snap-ring, Remove adjusting bolt / tapered bushing, Remove spring pack, Remove Piston
Reinstall: Drop in the piston (ensure puck remained seated), Drop in spring pad< Drop in piston bushing, Thread tapped bushing into the bed plate sleeve (hand tighten), Thread adjusting bolt into tappered bushing until it touches spring pack< See Torque Chart “Yaw Friction System-Adjusting Screw (100Nm + 300° torque&angle), Set hydraulic torque ratchet on adjusting bolt; Torque to 100 Nm, 5 out of 6 flats = 300° turned with low profile ratchet while watching marks
Insert snap ring, Back tappered bushing into snap-ring, Turn tight
For shaft/generator alignment, name the two planes and what viewing angle they represent.
Vertical = Side view
Horizontal = Top down view
For shaft/generator alignment, is the gearbox or generator moved?
Generator
The gearbox is the is the stationary unit and the generator is the movable unit.
For shaft/generator alignment, what are the two types of misalignment?
Angularity
and
Offset
1) For shaft/generator alignment, clock orientation is standing at what and looking at what?
2) To see the horizontal (top) plane use what two clock positions?
3) To see the vertical (side) plane use what two clock positions?
1) Standing at generator and looking at gearbox/rotor.
2) 3 and 9:00
3) 6 and 12:00
What are meggers?
Insulation testing meter that uses a capacitor and connects phase to ground.
