UL508A is the UL standard for the construction of Industrial Control Panels. This document gives guidelines to panel builders on various issues including proper component selection, wiring methods and calculation of short circuit current ratings. If a customer follows UL508A's construction requirements and recommendations, they can apply to have their panel listed by UL. Upon successful inspection, the panel would bear the UL label. A UL label signifies that the panel builder has met the requirements of UL508A, and that their panels are subject to inspection by UL field representatives. Not every panel is inspected by UL, but panels are subject to inspection by UL depending upon the quantity of UL Labeled panels made in a give time period. A UL Follow Up Services representative inspects the facility and reviews the panels to the UL508A Procedure for the particular panel shop being inspected. If the panels are found to be in compliance, they are permitted to continue production and apply the UL Label.
Retrieved from EATON at 11-11-2013