Ul 508a standard pdf download gaaphakerslingbeachs blog. Short circuit current ratings calculation and tools. The method stipulated in ul 508a, supplement sb, is also referenced in article 670, industrial machinery. Instruction sheets with sccr ratings ul tested combinations pdf. Ul 508a supplement sb is the preferred option for nearly all industrial control panels. Test each panel construction and record the construction in a followup procedure. Supplement sb, as an example for shortan approved method. Simplify your panel design and project organization.
Short circuit current rating sccr control concepts, inc. Determine the overall panel short circuit current rating according to sb4. Reference manual shortcircuit current rating sccr of. Nec article 409 references ul508a supplement sb as an approved method for determining the sccr of an industrial control panel. This rating is used to determine compliance with nec 110.
Ansiul 508a, standard for industrial control panels, supplement sb, is an example of an approved method. Control panel technical guide how to ensure troublefree approval of your ulcompliant control panels 6 1 ul standards and control panel design definition of electrical circuits as per standard ul 508a chap. Purchase previously tested combinations from a major supplier that can be tabulated in the panel builders procedure. Using currentlimiting fuses to increase sccr industrial control panels article 409 industrial machinery electrical panels article 670 multiple motor hvac equipment article 440 meter disconnect switches article 230 multiple motor controllers article 430 although sccr markings and labels are required by several. Evaluate panel per ul508a, supplement b required by 406 if jurisdiction does not adopt 2005 nec earlier.
Ul 508a standard pdf download a1d9fc608e share on facebook 31 aug 2010. In order to open a secure pdf, you will need to install the fileopen plugin and register your computer. Ul 508a industrial control panels power distribution and. Eaton is a major component supplier that is committed to providing this information to our customers. The ul 508a supplement sb method does not require the panel to be listed. And in the case of industrial control panels, change also tends to come slowly. Since 2006, manufacturers of custom control panels that have the ul listed. How to ensure troublefree approval of your ulcompliant. For many years, the ul508a supplement sb has been the approved method for calculation and determination of the short circuit current rating for industrial control panels. The component with the lowest sccr defines the sccr of the entire panel. A ul 508a certification is an industrial control panel directive, which electrical inspectors look for. The test has to be witnessed by a ul project engineer. Shortcircuit current rating markings are not required for industrial control panels containing only control circuit components. First, the term motor controller in the default sccr table sb 4.
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. Tested product combinations to meet nec article 409 and ul. All components in power circuit must have ratings ratings of starters are typically based on hp rating supplement sb, table sb4. 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 ul 508a supplement sb to. Per ul508a supplement sb, components that do, realized that any rating from this table is subject to meeting what ul defines as conditions of, inside the panel. Latest facebook app for nokia s40 latest facebook app for n. An internet connection is required to open a secure pdf.
Modify the sccr of certain series combinations if currentlimiting devices are used in the feeder circuit. Supplement sb, provides an analytical method to determine the short circuit current rating of an industrial control panel. Ul 508a standard pdf download a1d9fc608e share on facebook. Purchase ul standards online official ul standards sales. Underwriters laboratory implemented ul508a supplement sb. A brief history of ul 508a and tips for how control panel. This translates to applying the method described in ul508a supplement sb for calculating the sccr for industrial control panels. The secure pdf file needs to remain open for offline viewing. The ul listing mark on an industrial control panel provides evidence of third party certification to the. Sccr labeling is required on all panels and assemblies.
Shortcircuit current rating sccr a first, establish the short circuit current ratings of individual power circuit components as specified in sb4. Supplement sb in ul508a, which became effective on april 1, 2006, is referenced by the nec as an approved method for establishing the sccr of a panel. Three basic changes have been made to the latest edition of ul 508a, supplement sb dated february 4, 2010. Supplement sb, provides an analytical method to determine the shortcircuit current rating of an industrial control panel. Furthermore, all industrial control panels listed to ul508a must be marked with their sccr. Determine the sccr of all individual power components by one of the following methods. Ul 508a20, supplement sb, is an example of an approved method. This method is based upon the weakest link approach. Requirements for industrial control panel safety, implications of ul 508a 2nd edition panelbuilder 2 contents introduction 3. Ul 508a supplement sb sccr method ul 508a supplement sb describes three steps to determine the sccr of industrial control panels. Overview of supplement sb from the ul 508a standard. This supplement is the only method specifically noted as being. Short circuit current rating sccr is a rating on components and assemblies representing the maximum level of shortcircuit current that a component or assembly can withstand. How to determine shortcircuit current ratings iaei magazine.
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. These requirements also cover industrial control devices or systems that store or process information and are provided with an output motor control functions. Multiple revision in 2017 slide alignment of ul508a with nec. Advanced guide to understanding assembly shortcircuit current rating simplified guide to understanding shortcircuit current rating find it, fix it, forget it spd selecting protective devices sections on industrial. Establishing the sccr for solid state relays per ul508a, shortcircuit current. Formerly supplement sa of ul 508a 1 listed components 1. Sccr rating marked on the component use assumed sccrs in table sb 4.
It is a weakestlinkinthechain evaluation, meaning that the lowest sccr circuit within the panel. The elevator control panel shall not be installed where the available shortcircuit current exceeds its shortcircuit current rating, as marked in accordance with 620. Once you have all of the component ratings, either use an outside service or ul 508a supplement sb. 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. Supplement sb is the ul approved method for determining the sccr for industrial. Ul508a supplement sb4 is the approved method for determining short circuit current ratings for industrial control panels. Equipment intended to be connected to a source of supply greater. All control concepts fusion and compact fusion digital power controllers have been. Littelfuse using currentlimiting fuses to increase sccr pdf. The table on page four from the ul 508a supplement sb lists the ratings of common unmarked components and their default sccr rating unless you have an alternative, such as a tested combination from schneider. Determine the sccr of all individual power components and ul approved series ratings.
A secure pdf license can be reassigned to a different computer if necessary. The sccr of the control panel is based on the sccr of each component in the power circuit. Ul 508a control panel design guide the easytodesign guide for selection of electrical control components in control panels used in industrial machinery applications this guide is provided to assist with the design of control panels per ult 508a, specifically for use in industrial machinery applications. Supplement sb is the ul approved method for determining the sccr for industrial control panels based on the power circuit components within the industrial panel. When current limiting components are included within a portion of a circuit in the panel, modify the available short circuit current based on the letthrough values of the current limiting device. Ul 508a, supplement sb is an approved method to determine sccr for industrial control panels and industrial machinery control panels. Ul 508a supplement sb is given as an example of an approved method.
Does my phase monitor realy require a short circuit. Determining sccr for industrial control panels and industrial. Other application information on sccr publications. 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. With the numerous possibilities for product combinations within a panel, this option will require a tremendous investment in testing and maintenance. Nec article 409 and ul 508a shortcircuit current ratings. June 2018 55 may 2018 90 april 2018 36 march 2018 35 february 2018 28 january.