1 Scope

1.1 These requirements cover enclosed medium voltage power conversion equipment, such as variable frequency controllers, that control and transfer power to motors. These requirements also cover power-supply modules, input/output modules, and electronic assemblies, for use in or with power conversion equipment.

1.2 These requirements cover equipment rated above 1500 volts to 38kV. The equipment may have input ratings greater than 1500 V, output ratings greater than 1500 V, or both.

1.3 These requirements do not cover equipment for use in hazardous locations as defined by the National Electrical Code, NFPA 70.

1.4 These requirements do not cover solid state reduced voltage motor controllers (soft starters). This type of equipment is covered by the Standard for Medium Voltage AC Contactors, Controllers, and Control Centers, UL 347.

1.5 These requirements do not cover low voltage power conversion equipment with both input and output voltage ratings of 1500 volts and below. This type of equipment is covered by the Standard for Adjustable Speed Electrical Power Drive Systems – Part 5-1: Safety Requirements – Electrical, Thermal and Energy, UL 61800-5-1.

Summary of Topics

This revision of ANSI/UL 347A dated October 30, 2024 includes replacing withdrawn reference ANSI/ISA MC96.1 with ASTM E230/E230M: 4.2 and 32.2.27.