The table is equivalent to NEC 430.250 and the name used is full load current. In particular: 29.6.1 of UL 508A calls the currents in Table 50.1 full-load ampere rating. The use of full-load ampere rating in UL 508A should be changed to full-load current, where the meaning is the same, as stated in NFPA 79 or NEC. NEC (NFPA 70) requires in article 670.3(A)(1), the nameplate to include a list of information among which the " Full-load Current" of the panel. NFPA 79 calls it "full-load current" (Article 16.4). “UL 508A, in Clause 52.1 (that refers back to 49.1) requires the Panel Nameplate to provide the " Full-load Ampere rating" and be written in the nameplate. Hereafter some considerations for the changes. Therefore, in 2021, we submitted a Proposal Request to align the use of the two terms with what is in the NEC. In the past we, as GT Engineering, have always struggled with the fact the terms FLA and FLC were not used in a precise way throughout the UL 508A standard. Being members of the UL 508A Rooster, hereafter we give you some insights of the main changes. This designation indicates that the standard has been developed under a fair and open process designed to protect the rights and interests of every participant.Ī new update of the standard was officially published on 28 July 2022. 3 has been designated as an American National Standard (ANSI). The lastest release of this standard was in April 2018: UL 508A Ed. The equivalent of IEC 61439-2 (for switchboards) is UL 891 and of IEC 60204-1 (for industrial control panels for Machineries) is NFPA 79. In Europe, there is no equivalent standard, as you may know, to UL 508A. It also provides a well recognised method to calculate the Short-Circuit Current Rating of an Intustrial Control Panel. While the NFPA 79 provides prescriptions for industrial machinery control panels, UL508A has a broader scope and it focuses on the criteria that guarantee the safety of a control panel. Starting from the basics of electrical safety, stated by the NEC and looking at the prescriptions stated in NFPA 79, it gives indications for the design of industrial control panels. UL 508A is the technical standard for Industrial Control Panels in the USA.
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