Most recent
UL 508A Ed. 3-2018
Standard for Industrial Control Panels
This revision of ANSI/UL 508A dated April 16, 2020 includes the following changes in requirements: - ECBT2 Connectors in Control Circuits - SCCR for EMI Filters in Panels - Sizing of Branch Circuit Protection for Heat Loads - Emergency Stop Panels - Sizing the feeder: same approach for all Panels - SB4.3.3 - Addition of Class CFI - Multiple Disconnect sign - Revision to Section 55 - Markings - Revision of 31.4.1(c) to correlate with NEC 430.53(C)(1) - Bus Bar Construction Requirements for 100k/A SCCR without testing - Door interlocking / Restricted Access to Enclosures - Color Coding - Correction of 700A Class T fuse let-through in Table SB4.2 - Add UL 61010-2-201 to 42.2.3.1 Exception No. 2 - Editorial correction to 66.5.3
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