In 2005 ul 508a was changed to require control panel builders to include a short circuit current rating on the control panel assembly. Ul508a is the ul standard for the construction of industrial control panels. The table below is extracted from the ul 508a supplement sb, table sb4. This method is based upon the weakest link approach. With the numerous possibilities for product combinations within a panel, this option will require a tremendous investment in testing and maintenance. June 2018 55 may 2018 90 april 2018 36 march 2018 35 february 2018 28 january. Download free nec article 409 and ul 508a 4 siemens. Shortcircuit current rating application and codes training.
Nec article 409 and ul 508a shortcircuit current ratings sccr. Requirements for industrial control panel safety, implications of ul. Ul 508a, but is by no means an exhaustive guide, and does not cover all uses and applications associated with ul 508a regulations. Ul 508a supplement sb ul508a is a safety standard for industrial control panels adopted by underwriters laboratory which is an approved method in determining sccr referenced by nec article 409. Underwriters laboratory implemented ul508a supplement sb. All components in power circuit must have ratings ratings of starters are typically based on hp rating supplement sb, table sb4. Requirements for industrial control panel safety, conductors. Each copy is watermarked with the purchasers information. Reference manual shortcircuit current rating sccr of. Ul 508a online certifications directory outline of ul 508a slide 3 industrial control procedure ul508a descriptive procedure part 1 general use supplement sa. Ul 508a, supplement sb, provides an analytical method to determine the shortcircuit current rating of an industrial control panel. Ul 508a standard pdf download gaaphakerslingbeachs blog. Harmonization of iec and north american safety standards.
Please refer to the ul website to view the most uptodate table sb4. Ul 508a industrial control panels power distribution and control. In order to open a secure pdf, you will need to install the fileopen plugin and register your computer. Ul 508a covers industrial control panels and industrial panel enclosures operating at 600 volts. For each, protection and control functions are stipulated. Join us for a 3hour training session on equipment shortcircuit current ratings sccrs and national electrical code nec requirements, understanding industrial control panels devices, and ul 508a supplement sb. Evaluate panel per ul508a, supplement b required by 406 if jurisdiction does not adopt 2005 nec earlier. Ul 508a supplement sb ul 508a supplement sb describes three steps to determine the sccr of industrial control panels. Purchase ul standards online official ul standards sales. Formerly supplement sa of ul 508a 1 listed components 1. Ul508a and ul698a labeling issues comes up quite often, so we can help you take some of the pain and cost out of the process of getting your panels labeled. The process for ul 508a, supplement sb analyzes the sccr for power circuit components, determines if these ratings can be raised by currentlimiting devices in the feeder circuit, and compares the lowest component rating with the lowest interrupting rating of overcurrent devices to determine the assembly sccr.
Control panel technical guide how to ensure troublefree approval of your ulcompliant control panels 8 2 ul standards and circuit design design of a motor circuit as per standard ul 508 part iv and ul 508a chap. Ul 508a supplement sb sccr method ul 508a supplement sb describes three steps to determine the sccr of industrial control panels. Equipment sccr, industrial control panel devices and ul 508a supplement sb. It supersedes the previous version of this document. Overview of supplement sb from the ul 508a standard. Ul 508a, supplement sb, provides an analytical method to determine the sccr of an industrial control panel. Sccr of a listed and labeled assembly, or sccr based on use of an approved method ul 508a supplement sb is given as an example of an approved method as of april 25, 2006, all ul 508a listed panels must be marked with sccr. Jul 07, 2015 in 2005 ul 508a was changed to require control panel builders to include a short circuit current rating on the control panel assembly. Ul 508a standard pdf download a1d9fc608e share on facebook. How to ensure troublefree approval of your ulcompliant. Tested product combinations to meet nec article 409 and ul. Ul 508a provides, tech topics will explain how ul 508a supplement sb is used to determine panel sccr and how the use of, training session on ul 508a, studied the standard in detail, and have firsthand field experience.
Modify the sccr of certain series combinations if currentlimiting devices are used in the feeder circuit. This white paper explains how ul 508a supplement sb is used to determine panel sccr and how the use of typetested components and current. References in this document to sections or paragraphs in ul 508a are understood to be to the third edition of the standard with revisions dated july 3. While that seems a reasonable request, and is certainly in the best interest of safety, in practice it can be difficult to comply with. Quality, efficiency, reduced costs and consumer confidence are some of the other benefits of having been certified by a ul 508a panel shop. Ul 508a online certifications directory outline of ul 508a slide 3 industrial control procedure ul508a descriptive procedure part 1 general use supplement sa specific component requirements part 2 specific use information you provide specific components not.
But safety is only one feature of having a certified ul 508a panel. Design of a motor circuit as per standard ul 508 part iv and ul 508a chap. Control panels containing predominately communication equipment, such as telephone equipment and intended for installation in accordance with chapter 8 of the nec, is evaluated to the standard for information technology equipment safety part 1. Overview of code changes in nec article 409 overview of ul 508a supplement sb. In the case of a motor feeder, a number of component combinations may be used to ensure the functions, however. Underwriters laboratory implemented ul 508a supplement sb to require compliance by ul authorized panel builders. With the release of the ul 508a, ul standard for safety for industrial control panels, an industryapproved method is now available. Sccr rating marked on the component use assumed sccrs in table sb 4. Always consult all pertinent actual regulatory standards and local standard representatives to ensure full compliance. Purcell systems manufactures ul 508a certified enclosures and cabinets to the ul 508a safety standard this manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent damage to property. How to determine shortcircuit current ratings iaei magazine.
Nec requirements for shortcircuit current ratings iaei. Test each panel construction and record the construction in a followup procedure. Ul 508a industrial control panels power distribution and. Please allow ample time for delivery through the us postal service. Nec article 409 and ul 508a shortcircuit current ratings. Determine the sccr of all individual power components and ul approved series ratings. Supplement sb is the ul approved method for determining the sccr for industrial control panels based on the power circuit components within the. Apr 06, 2018 equipment sccr, industrial control panel devices and ul 508a supplement sb. This document gives guidelines to panel builders on various issues including proper component selection, wiring. Equipment intended to be connected to a source of supply greater. This guide is not intended to be used in lieu of ul 508a or other regulatory standards. Shortcircuit current rating markings are not required for industrial control panels containing only control circuit components. Underwriters laboratory implemented ul508a supplement sb to. We design, assemble, and install ul certified panels and can bring existing control panels up to ul safety standards, as well as build panels from the ground up meeting the customer requirements, while following ul safety standards.
Ul 508a supplement sa specific component requirements. Ul is a global independent safety science company offering expertise across three strategic businesses. Ul 508a provides analytical method for determining panel. The process for ul 508a, supplement sb analyzes the sccr for power circuit components, determines if these ratings can be raised by currentlimiting devices in the feeder circuit, and compares the lowest component rating with the lowest interrupting rating of overcurrent devices. Nec article 409 and ul 508a shortcircuit current rating sccr of industrial control panels. The ul listing mark on an industrial control panel provides evidence of third party certification to the municipal inspection authority and to the purchaser of the panel. Schneider electric codes and standards 2017 nec changes. Ansiul 508a, standard for industrial control panels, supplement sb, is an example of an approved method. Ul standard for safety for industrial control panels. Once you have all of the component ratings, either use an outside service or ul 508a supplement sb. Determine the sccr of all individual power components by one of the following methods.
Basic steps for calculating the sccr of a control panel. Each license entitles a user to download the file to their pc and print 1 copy. Ul508a supplement sb4 is the approved method for determining short circuit. Ul 508a covers industrial control panels and industrial panel enclosures operating at 600. Uls notforprofit, independent status allows it to be unbiased in determining whether or not a product meets recognized safety standards. Ansi ul 508a, standard for industrial control panels, supplement sb, is an example of an approved method. A brief history of ul 508a and tips for how control panel. Ul 508a standard pdf download a1d9fc608e share on facebook in industrial control panels according to ul508a. Ul now offers the ability to purchase a premium hard copy of any ul standard. The sccr requirements for ul 508a are effective after april 25, 2006.
A ul 508a certification is an industrial control panel directive, which electrical inspectors look for. This document replaces what was supplement sa in the second edition of ul 508a, and subsequently appendix c in the third edition of ul 508a. Ul 508a, supplement sb is an approved method to determine sccr for industrial control panels and industrial machinery control panels. Underwriters laboratory 508a overview of ul508a supplement sb ul 508a is a safety standard for industrial control panels adopted by underwriters laboratory, which is an approved method in determining sccr referenced by nec article 409.
Ul 508a standard for industrial control panels standards. Page ul enclosed sccr 1 air ul 508a ul 508a 1995 376. Requirements for industrial control panel safety, implications of ul 508a 2nd edition. Latest facebook app for nokia s40 latest facebook app for n.