Ul 508a supplement sb defines a procedure for determining the equipment sccr. Equipment sccr, industrial control panel devices and ul 508a supplement sb. How to ensure troublefree approval of your ulcompliant. Supplement sb is the ul approved method for determining the sccr for industrial control panels based on the power circuit components within the. Harmonization of iec and north american safety standards. This guide replaces neither the standards including ul 508a that electrical. The method mentioned in ul 508a supplement sb can be quickly summarized as follows.
A brief history of ul 508a and tips for how control panel. Ul 508a provides analytical method for determining panel. The informational note mentions supplement sb in ul 508a as an example of an approved method. 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.
Ul 508a supplement sb sccr method ul 508a supplement sb describes three steps to determine the sccr of industrial control panels. How to determine shortcircuit current ratings iaei magazine. Equipment intended to be connected to a source of supply greater. 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. This can be determined by testing or by analysis in accordance with the requirements added to ul 1995 which are similar to that of ul 508a, supplement sb. Ul508a is a safety standard for industrial control panels adopted by. Nec article 409 and ul 508a shortcircuit current ratings. Ul 508a standard for industrial control panels purcell systems. Evaluate panel per ul508a, supplement b required by 406 if jurisdiction does not adopt 2005 nec earlier. The nec proposes the method stipulated in ul 508a, supplement sb, as an example for an approved method. This is typically somewhere between 240vac 600vac, 3 phase power.
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. Determination of the sccr values of individual components. All components in power circuit must have ratings ratings of starters are typically based on hp rating supplement sb, table sb4. Control panel technical guide how to facilitate the ulcompliant. Download it for free by clicking on the register for free download link and.
Formerly supplement sa of ul 508a 1 listed components 1. These requirements also cover industrial control devices or systems that store or process information and are provided with an output motor control functions. Supplement sb allows the panel manufacturer to assign an sccr to a panel without testing the assembled panel. The nec article 409 refers to the ul 508a supplement sb as an approved method for determining the sccr of an industrial control panel. How to ensure troublefree approval of your ulcompliant control panels. Please allow ample time for delivery through the us postal service. The method stipulated in ul 508a, supplement sb, is also referenced in article 670, industrial machinery. Each copy is watermarked with the purchasers information. Requirements for industrial control panel safety, conductors. Industrial control panels, supplement sb, is an example of an approved method. Using currentlimiting fuses to increase short circuit. Ul 508a standard pdf download a1d9fc608e share on facebook in industrial control panels according to ul508a. Ul 508a, supplement sb identifies an approved process that can be used to.
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. Standards for safety ul 508a underwriters laboratories inc. Ul set of safety standards covering industrial control panels intended for general industrial use, operating from a voltage of 600 volts or less. Ul 508a supplement sb assigns a maximum sccr of only 200 amperes to unmarked. The acceptability of the combination will be determined when the complete product is. Bussmannhorizon sccr web series tickets, tue, apr 14. With the release of the ul 508a, ul standard for safety for industrial control panels, an industryapproved method is now available. Determining sccr for industrial control panels and. This white paper explains how ul 508a supplement sb is used to determine panel sccr and how the use of typetested components and current. 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. The ul 508a 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. Ul 1995, the ul standard for safety for heating and cooling equipment, recently was updated to require hvac equipment to be marked with an sccr, effective july 2012. Always consult all pertinent actual regulatory standards and local standard representatives to ensure full compliance.
Ul 508a, supplement sb is an approved method to determine. Currently, ul 508a supplement sb does not use the apparent root mean square rms. Ul 508a supplement sb ul 508a supplement sb describes three steps to determine the sccr of industrial control panels. Short circuit current ratings calculation and tools. If hvac equipment manufacturers choose to use another approved method, ul 508a, ul standard for safety for industrial control panels, is available, and supplement sb to ul 508a provides an analytical method of determining the sccr of an industrial control panel. Shortcircuit current rating of hvac equipment dan neeser. This award winning design tool allows you to comply quickly and accurately with 2008 nec and ul 508a supplement sb for assembly sccr marking requirements. Ul now offers the ability to purchase a premium hard copy of any ul standard. It supersedes the previous version of this document. Modify the sccr of certain series combinations if currentlimiting devices are used in the feeder circuit. Ul 508a certification is an industrial control panel directive, which is sought by electrical inspectors. Shortcircuit current rating sccr of industrial control panels reference manual, 0620, a5e31896849002arsaa001 11 overview of supplement sb from the ul 508a.
The city inspector will generally not have a copy of the standard in order to know what supplement sb actually says. Requirements for industrial control panel safety, implications of ul 508a 2nd edition. Ul 508a standard pdf download gaaphakerslingbeachs blog. The second day instructs industrial control panel customers on how to establish shortcircuit ratings for individual industrial control panels in accordance with the requirements outlined in the new standard for industrial control panels, ul 508a, 3rd edition, supplement sb. Sccr rating marked on the component use assumed sccrs in table sb 4. Overview of supplement sb from the ul 508a standard.
Ul standard for safety for industrial control panels. Excerpts from ul 508a standard for safety for industrial control panels are the. Instruction sheets with sccr ratings ul tested combinations pdf. Ul 508a industrial control panels power distribution and. Supplement sb, provides an analytical method to determine the shortcircuit current. 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. This method is based upon the weakest link approach. Determine the sccr of all individual power components and ul approved series ratings. Ul 508a certification description from quality controls, inc. Ansi ul 508a, standard for industrial control panels, supplement sb, is an example of an approved method.
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 sa specific component requirements ul. Three main considerations are used to determine the sccr of an industrial control panel according to ul 508a, supplement sb analysis method. Purchase ul standards online official ul standards sales. Apr 06, 2018 equipment sccr, industrial control panel devices and ul 508a supplement sb. Ansiul 508a, standard for industrial control panels, supplement sb, is an example of an approved method. Shortcircuit current rating sccr a first, establish the short circuit current ratings of individual power circuit components as specified in sb4. In some cases, sccr may also facilitate lower insurance rates through compliance with codes such as the national fire protection associations nfpa 70e code and the ul 508a supplement sb. This document gives guidelines to panel builders on various issues including proper component selection, wiring. Understanding ul508a for industrial control panels applied. The ul 508a supplement sb method of assigning the sccr to an industrial control panel does not require the panel be listed.
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. At the municipal, county and state levels, electrical codes are being amended at an increasing rate to include the requirement for sccr labeling of industrial control panels per nec409. Ul certification customers have free access to ul standards, not including ul iec based standards. We will help with the acceptance ul 508a standard pdf download a1d9fc608e share on facebook in industrial control panels according to ul508a. Ul 508a, supplement sb, provides an analytical method to determine the shortcircuit current rating of an industrial control panel. Ul 508a20, supplement sb, is an example of an approved method. Ppt nec article 409 powerpoint presentation free to view. Supplement sb describes how to assign the sccr to a panel based on the ratings of the individual power components and types of currentlimiting power devices used within the panel. If your jurisdiction does not adopt the 2005 code, control panels certified to the ul 508a standard will require a sccr rating in april 2006. Ul 508a supplement sb is the preferred option for nearly all industrial control panels. Reference manual shortcircuit current rating sccr of.
Ul compliant control panels technical guide schneider. Prior to the release of the latest edition of ul 508a, supplement sb dated december 20, 20, sccr applied only to the power circuit of a control panel. Ul508a is the ul standard for the construction of industrial control panels. This equipment is intended for installation in ordinary locations, where the ambient temperature does not exceed 40c maximum. Underwriters laboratory implemented ul 508a supplement sb to. Utilize a method described by underwriters laboratories inc.
The elevator control panel shall not be installed where the available shortcircuit current exceeds its shortcircuit current rating, as marked in accordance with 620. 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. Supplement sb, provides an analytical method to determine the short circuit. Control panel technical guide how to ensure trouble free approval of your ul compliant 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 20, supplement sb, is an example of an approved method. Compliance with the 2017 nec for elevator controllers. This document is intended to be used to determine the requirements for components when used in industrial control panels. Ul 489 moldedcase circuit breakers, moldedcase switches. Underwriters laboratory implemented ul 508a supplement sb to require compliance by ul authorized panel builders. Overview of code changes in nec article 409 overview of ul 508a supplement sb. This 3part web series will address sccr codes and applications, industrial control panels and ul 508a supplement sb to provide an overview of sccr determination.
Ul standard for safety for industrial control panels, ul 508a second edition, dated december 20, 20 summary of topics this revision of ul 508a is issued to correct table sb4. Ul 508a covers industrial control panels and industrial panel enclosures operating at 600 volts. Supplement sb is the ul approved method for determining the sccr for. Shortcircuit current rating markings are not required for industrial control panels containing only control circuit components. This supplement is the only method specifically noted as being. The sccr can be based on an assembly product standard listing and labeling, or an approved analysis method, such as ul 508a, supplement sb. Ul 508a sb determining sccr three basic steps ul 508a supplement sb shortcircuit current ratings for industrial control panels shall be determined by the following evaluation procedure. Control panel technical guide how to ensure troublefree approval of your. Latest facebook app for nokia s40 latest facebook app for n. 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. Once you have all of the component ratings, either use an outside service or ul 508a supplement sb.
This guide is not intended to be used in lieu of ul 508a or other regulatory standards. Sa in the second edition of ul 508a, and subsequently. Underwriters laboratory implemented ul508a supplement sb. The power circuit supplies electricity to the workers that do the heavy lifting, powering large motors, for example. Ul 508a industrial control panels power distribution and control. Ul 508a online certifications directory outline of ul 508a slide 3 industrial control procedure ul508a descriptive procedure part 1 general use supplement sa. Article requires all industrial control panels to be marked with a short circuit current. While that seems a reasonable request, and is certainly in the best interest of safety, in practice it can be difficult to comply with.
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