UL 347D:2017 PDF Download

The UL 347D:2017 standard provides requirements for equipment that incorporates switching elements for making and breaking the stator circuit of wind turbines. These requirements cover equipment with AC voltage ratings above 1500 V, up to 15 kV, and are intended for use in ordinary locations in accordance with the National Electrical Code.

The standard does not cover variable speed motor controllers (power conversion equipment) or equipment intended for starting, stopping, regulating, controlling, or protecting electric motors or other electrical loads. Such equipment is covered by the Standard for Medium-Voltage AC Contactors, Controllers, and Control Centers, UL 347.

It is important to note that the UL 347D:2017 standard is not intended to replace the requirements of IEEE 1547.1, which sets the standard conformance test procedures for equipment interconnecting distributed resources with electric power systems. When the equipment covered by UL 347D is used as part of an interconnected system, it is expected that the entire system will be investigated to the requirements of IEEE 1547.1 as appropriate.

The standard also includes normative references, component standards, and general requirements. The products covered by this outline must comply with the reference installation codes and standards noted in Annex A of UL 347. Components utilized in the products must comply with the appropriate standards for these components and their recognized ratings and limitations of use. The standard provides a partial listing of applicable component standards in Annex D.

In terms of measurement, the units given in SI (metric) units are normative, while any other values given are for information purposes only.