UL 6141

Standard for Wind Turbines Permitting Entry of Personnel

1.1 These requirements cover large wind turbine systems (WT) that are equipped with electrical subassemblies and permit the entry of personnel. With respect to this standard, WT permitting entry of personnel are considered to be wind turbines where a user or service person may, or is intended to, enter the turbine to operate it or perform maintenance. These WT are intended for use in utility-interactive, grid-tied applications that operate in parallel with an electric power system (EPS) to supply power to common or stand-alone loads. This standard includes requirements for WT intended for EPS grid connections at transmission, sub-transmission, and distribution levels depending on the specifications of the specific WT.

1.2 The WT power, control and protection systems are evaluated only to the extent that they function within the manufacturer's specified limits and response times. These control and protection functions are evaluated with respect to risk of electric shock and fire. It is intended that the electrical subassemblies that address power transfer and control and protection functions evaluated per this document are to be coordinated with the mechanical and structural evaluation of the WT in accordance with the IEC 61400 series of documents.

1.3 These requirements do not cover:

a) Wind turbine generating systems intended for offshore installation,

b) Mechanical or structural integrity of the WT or subassemblies,

c) Verification that the manufacturer-defined controls and protection limits maintain the WT within its safe mechanical and structural limits,

d) Compliance with specific grid interconnection standards or requirements.

1.4 The wind turbine products covered by these requirements are intended to be installed in multiple installation locations and jurisdictions which may include installation codes including, but not limited to, the National Electrical Code, ANSI/NFPA 70, the National Electrical Safety Code (NESC), and NFPA 79, Electrical Standard for Industrial Machinery.

1.5 The wind turbine products covered by this standard are considered to be machines that include inherent internal hazards that make them unsuitable for access by the general public.

1.6 The users, operators and service persons that enter this equipment are expected to have the necessary knowledge of its operation and reasonably foreseeable hazards. These individuals are expected to be equipped with the necessary equipment for the application and hazard.

1.7 The evaluation of products to this standard includes the evaluation of all features and functions incorporated in or available for the WT that can affect compliance of the WT with this standard. This includes references in the documentation for the WT.

1.8 Small WT and electrical subassemblies are defined as wind turbines where a user or service person is not intended or required to enter the WT to operate or perform maintenance on the WT. Small wind systems are covered in the Standard for Small Wind Turbine Systems, UL 6142.


  • Edition Number: 1
  • Edition Date: 05/20/2016
  • Price Code: A
  • Type: ulstd
  • ANSI Approved: 05/20/2016
  • DOD Approved: