UL 347A:2021 PDF Download

The UL 347A:2021 standard covers enclosed medium voltage power conversion equipment, such as variable frequency controllers, which are used to control and transfer power to motors. This includes power-supply modules, input/output modules, and electronic assemblies designed to be used with power conversion equipment.

The standard applies to equipment rated above 1500 volts up to 38kV. This includes equipment with input ratings greater than 1500 volts, output ratings greater than 1500 volts, or both.

However, it's important to note that the standard does not cover equipment for use in hazardous locations as defined by the National Electrical Code, NFPA 70.

Additionally, the standard does not cover solid-state reduced voltage motor controllers (soft starters), as they are covered by a separate standard, UL 347. It also does not cover low voltage power conversion equipment with both input and output voltage ratings of 1500 volts and below. This type of equipment falls under the scope of the Standard for Adjustable Speed Electrical Power Drive Systems – Part 5-1: Safety Requirements – Electrical, Thermal and Energy, UL 61800-5-1.