WTT Cheat Sheet 2026

The 30 highest-yield WTT facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What does WLL stand for in the context of rigging equipment? → Working Load Limit
2. What does the term 'gear ratio' mean in a wind turbine gearbox? → The ratio of output shaft speed to input shaft speed
3. When performing a gearbox oil change, why is it important to flush with clean oil before filling with fresh oil? → To remove residual degraded oil and metal particles that could contaminate the new charge
4. Which NFPA standard provides guidelines for technical rescue operations, including high-angle rescues at wind turbines? → NFPA 1006
5. Which lubrication method is used for wind turbine main shaft bearings in most 2 MW+ direct-drive designs? → Centralized automatic grease lubrication systems with programmed relubrication intervals
6. What is the purpose of grounding electrical systems in wind turbines? → To safely dissipate any excess electrical energy.
7. ISO VG 46 hydraulic oil is specified for a turbine. Which alternative viscosity grade is acceptable in an emergency if VG 46 is unavailable? → ISO VG 32 or VG 68 within the OEM's approved range
8. During PM, a technician checks the cooling system of a liquid-cooled generator and finds coolant level low. What should be done before adding coolant? → Inspect for leaks, identify and repair the source, then refill to specified level
9. What does 'preload' mean in the context of wind turbine main shaft bearings? → A deliberately applied axial force that removes internal clearance from the bearing
10. In Blade Inspection & Maintenance, what is the FIRST step a WTT professional should take when encountering a new case or situation? → Conduct a comprehensive assessment and gather all relevant information
11. What is the PRIMARY purpose of continuing education requirements in Mechanical Systems & Drivetrain for WTT professionals? → Maintaining current knowledge and competency as the field evolves
12. What is the primary purpose of performing an oil particle count analysis on gearbox oil? → To detect early-stage wear before catastrophic failure occurs
13. What is the maximum wind speed at which most manufacturers permit turbine tower climbing operations? → 20 mph (32 km/h)
14. A turbine repeatedly faults on 'grid voltage out of range.' After confirming the fault is not caused by the turbine itself, the technician should: → Document the fault and contact the grid operator to investigate supply voltage issues
15. A technician is troubleshooting a SCADA alarm indicating 'Earth Fault on LV Bus.' Which instrument would best pinpoint the faulted feeder? → Insulation resistance tester (megger) on de-energized feeders one at a time
16. Which parameter is most critical when selecting grease for wind turbine pitch and yaw bearing lubrication? → NLGI grade and base oil viscosity appropriate for low temperature and high load
17. What is the minimum D/d ratio typically required for a wire rope sling when it is bent around a pin or lifting point? → 5:1
18. When a pitch battery backup system fails to hold charge, what is the most likely consequence during a grid fault? → The blades may fail to feather, causing an uncontrolled overspeed
19. What is the PRIMARY purpose of continuing education requirements in Electrical Systems & Power Generation for WTT professionals? → Maintaining current knowledge and competency as the field evolves
20. What is the primary advantage of a direct-drive wind turbine configuration compared to a geared drivetrain? → Elimination of gearbox reduces mechanical losses and removes a major maintenance item
21. When inspecting a high-speed shaft coupling, which defect is most critical to address immediately? → Cracked or missing elastomeric coupling elements
22. A lightning strike receptor on a blade tip that is cracked or corroded should be: → Replaced immediately to maintain the blade's lightning protection system integrity
23. What is the purpose of checking the pitch bearing grease nipple fittings during a scheduled PM? → To ensure grease can be injected and the old grease is being purged
24. What does 'availability factor' measure in wind turbine SCADA performance reporting? → The percentage of time a turbine is capable of producing power when wind conditions permit
25. What condition requires a synthetic web sling to be immediately removed from service? → Acid or caustic burns, melting, or charring of fibers
26. A wind turbine technician is working on a gearbox and must drain hot gear oil. Which PPE is specifically required beyond standard PPE? → Chemical-resistant gloves and face shield rated for hot liquids
27. Which communication protocol should be used when a technician at the top of the tower loses radio contact with the ground crew? → Use the pre-established emergency signal system (e.g., rope pulls or light signals)
28. When a conflict arises between standard procedures and a unique situation in Wind Turbine Components & Design, what should a WTT professional prioritize? → Safety and ethical obligations while seeking expert consultation
29. What is the purpose of a dV/dt filter installed on the output of a wind turbine's PWM inverter? → To limit the rate of voltage rise that could damage generator winding insulation
30. A technician notices ice formation on ladder rungs before beginning a climb. What is the correct action? → Delay the climb until ice is removed and rungs are dry