UL 347C:2014 PDF Download

The UL 347C:2014 standard outlines the requirements for medium voltage solid state resistive load controllers with voltage ratings above 1500 V up to 15 kV. These controllers are used for starting, stopping, regulating, controlling, or protecting resistive loads such as heating systems.

The standard does not cover variable speed motor controllers or power conversion equipment. It applies to equipment intended for use in ordinary locations as defined by the National Electrical Code.

Equipment intended for controlling electric motors or other electrical loads, including refrigeration equipment, are covered by separate standards such as the Standard for Medium-Voltage AC Contactors, Controllers, and Control Centers (UL 347) or the Outline for Medium Voltage Motor Controllers, Up to 15 kV, Subject 347B.

In certain cases, the requirements specified in the Standard for Medium-Voltage AC Contactors, Controllers, and Control Centers (UL 347) also apply to the medium voltage solid state resistive load controllers covered by this standard.