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 given 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.
A UL listed component bears the UL listing mark and has been subject to testing. The UL Listed label is evidence that the manufacturer submitted complete product samples for testing, witnessed by UL representatives. These products are subject to testing and evaluation by UL and were found to meet nationally recognized safety standards. Products can also be “UL Recognized”, which means that the product was found to be safe in particular when reviewed and accepted by UL in the final application. OEMs utilizing UL Recognized components in a control panel must ensure that their application meets additional requirements described in their UL procedure.