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New UL Variable-Frequency Drive Standard and Its Effects on Unit Short Circuit Rating

NEMA IA 10045-2025 | Status: Active | ID: 100732

In February 2013 Underwriters Laboratories (UL) released UL61800-5-1, a new standard for variable- frequency drives, which has replaced the existing UL508C standard. The development of UL61800-5-1 was a harmonization that brought IEC 61800-5-1 and UL508C drive standards closer together. The differences between UL61800-5-1 and IEC 61800-5-1 standards are noted in the National Differences document. Please refer to the following for specific details and timing of this new approach.

Published Date: December 4, 2025

Number of pages: 4

Staff Contact: David Richmond

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Keywords

NEMA IA 10045-2025, DRIVES, SHORT-CIRCUIT, BREAKDOWN OF COMPONENTS, BRANCH-CIRCUIT PROTECTION,