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Inspections and Root Cause Analysis

Rely on UL services and support to help achieve a successful long-term operation of your wind farm.

Employees performing a wind turbine inspection

Technical safety for long-term wind farm management

Helping to ensure safe and efficient operations, UL offers independent technical inspections on wind turbines and components through the project life cycle. We provide services that allow project developers, wind project owners and investors to combine technical safety with a reliable management plan for the long-term operation of the wind farm.

Wind turbine inspections

Wind turbine inspections are important, and often required, at various stages of the wind project life cycle to help ensure reliability, safety and performance. We offer inspection services for onshore and offshore wind turbines and their components. We provide completely independent and objective information to accurately characterize their current condition, identify technical issues, and document all findings and recommendations in an accredited report.

Inspection performance locations

  • Factories, including the manufacturing quality control process
  • Origin and destination ports and hubs
  • Transportation means for main components
  • On-site during the project construction and operation

Inspections can be performed at different stages of a project’s lifecycle

  • At any point in the supply chain, to verify the quality of components
  • After COD, to establish a punch list before signing an approval certificate
  • Before the end of warranty, to help ensure that warranty claims and contractual obligations of the manufacturer are fulfilled before the deadlines
  • During the life of the wind project, recommended every two to four years
  • At the end of a wind project’s design life, to determine the remaining useful life

Wind turbine inspections include inspection of their main components

  • Endoscopic inspection on gearboxes, bearings, main shafts and pitch systems
  • Vibration measurement and diagnosis for the drive train and shaft alignment
  • Inspection of blade and/or blade lightning protection system from the ground, uptower or with drones
  • Insulation test on generator
  • Additional reviews, including oil and grease analysis, ultrasounds, penetrating liquids and more

Root cause analysis (RCA) and damage assessment

When turbines are damaged, our qualified inspectors and structural and mechanical experts conduct a root cause analysis (RCA) to determine the reasons. It is of critical importance to evaluate the pervasiveness of the causes across the complete wind project and clearly define measures to mitigate the consequences. Our RCA processes are based on proven methodologies (including IEC 62740), which entail gathering all facts surrounding the incident and methodically reaching a conclusion.

We offer testing and, if applicable, certification to the requirements of:

  • US: UL 6141, the Standard for Wind Turbines Permitting Entry of Personnel
  • US: UL 6142, the Standard for Small Wind Turbine Systems
  • Japan: JSWTA0001 (small WT)
  • UK: IEC 61400-2, MCS (small WT)
  • German type approval (DiBT)
  • Korean type approval (KEA Scheme)
  • IECRE

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