{"id":39459,"date":"2023-01-05T14:02:59","date_gmt":"2023-01-05T13:02:59","guid":{"rendered":"https:\/\/www.gt-engineering.it\/normative-tecniche\/%tipologia_normativa%\/ul-508a\/"},"modified":"2026-04-25T11:54:26","modified_gmt":"2026-04-25T10:54:26","slug":"ul-508a","status":"publish","type":"normativa_tecnica","link":"https:\/\/www.gt-engineering.it\/fr\/reglements-techniques\/normes-americaine\/ul-508a\/","title":{"rendered":"UL 508A: Panneaux de contr\u00f4le industriels"},"content":{"rendered":"\n\n    \n        <section\n            data-name=\"Contenuto testuale con immagine\"\n            class=\"bow-gte-testo-media u-spacer-base\"\n            id=\"\"\n        >\n            \n<div class=\"o-text-media px-side-spacer sm:px-side-spacer-sm lg:px-side-spacer-tablet 2xl:px-side-spacer-desktop flex flex-wrap items-start md:block\">\n\n    \n        \n                    <div\n                class=\"h-auto mb-6 md:mb-4 lg:mb-8 xl:mb-9 float-left mr-6 md:mr-4 lg:mr-8 xl:mr-9  overflow-hidden shadow-content-image w-full md:w-1\/3\"\n            >\n                \r\n\r\n    \r\n        \r\n            \r\n                \r\n                    <picture\r\n                        class=\"\"\r\n                                            >\r\n                                                                                                        <source\r\n                                media=\"(max-width: 150px)\"\r\n                                width=\"150\"\r\n                                height=\"150\"\r\n                                srcset=\"https:\/\/www.gt-engineering.it\/wp-content\/uploads\/2023\/01\/premiere-page-1-150x150.jpeg.webp\"\r\n                                type=\"image\/webp\"\r\n                            \/>\r\n                                                                                <source\r\n                                media=\"(max-width: 225px)\"\r\n                                width=\"225\"\r\n                                height=\"300\"\r\n                                srcset=\"https:\/\/www.gt-engineering.it\/wp-content\/uploads\/2023\/01\/premiere-page-1-225x300.jpeg.webp\"\r\n                                type=\"image\/webp\"\r\n                            \/>\r\n                                                                                <source\r\n                                media=\"(max-width: 768px)\"\r\n                                width=\"768\"\r\n                                height=\"1024\"\r\n                                srcset=\"https:\/\/www.gt-engineering.it\/wp-content\/uploads\/2023\/01\/premiere-page-1-768x1024.jpeg.webp\"\r\n                                type=\"image\/webp\"\r\n                            \/>\r\n                                                                                <source\r\n                                media=\"(max-width: 768px)\"\r\n                                width=\"768\"\r\n                                height=\"1024\"\r\n                                srcset=\"https:\/\/www.gt-engineering.it\/wp-content\/uploads\/2023\/01\/premiere-page-1-768x1024.jpeg.webp\"\r\n                                type=\"image\/webp\"\r\n                            \/>\r\n                                                                            <img\r\n                            class=\"a-image transparent border-image h-auto  w-full\"\r\n                                                        srcset=\"https:\/\/www.gt-engineering.it\/wp-content\/uploads\/2023\/01\/premiere-page-1.jpeg.webp\"\r\n                                                        title=\"premiere page\"\r\n                                                        type=\"image\/webp\"\r\n                        \/>\r\n                    <\/picture>\r\n\r\n                \r\n\r\n                    \r\n    \r\n            <\/div>\n        \n                    <div class=\"relative w-full\">\n                \n<div class=\"a-text font-text text-base normal mt-8 first:mt-0 space-y-4\">\n    <p data-start=\"131\" data-end=\"386\"><strong data-start=\"131\" data-end=\"172\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">UL 508A<\/span><\/span><\/strong> est la principale norme technique r\u00e9gissant la conception et la fabrication des <strong data-start=\"253\" data-end=\"289\">panneaux de commande industriels<\/strong> aux \u00c9tats-Unis. Son \u00e9quivalent au Canada est la norme <strong data-start=\"344\" data-end=\"385\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">CSA C22.2 No. 286<\/span><\/span><\/strong>.<\/p>\n<hr data-start=\"388\" data-end=\"391\" \/>\n<h3 data-section-id=\"awhxnz\" data-start=\"393\" data-end=\"430\"><strong><u><span dir=\"auto\">Origines de UL 508A : la \u00ab drawer standard \u00bb<\/span><\/u><\/strong><span dir=\"auto\">\u00a0\u00a0<\/span><\/h3>\n<p data-start=\"432\" data-end=\"751\">UL 508A trouve son origine dans ce que l\u2019on appelle informellement une <em data-start=\"503\" data-end=\"524\">\u00ab drawer standard \u00bb<\/em> (norme de tiroir). Cette expression d\u00e9signe des documents techniques \u00e9labor\u00e9s en interne par les ing\u00e9nieurs de <strong data-start=\"636\" data-end=\"677\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">UL Solutions<\/span><\/span><\/strong> et utilis\u00e9s exclusivement dans le cadre de la certification des produits.<\/p>\n<p data-start=\"753\" data-end=\"1194\">Dans les ann\u00e9es 1970, l\u2019<strong data-start=\"777\" data-end=\"816\">Authority Having Jurisdiction (AHJ)<\/strong> de Chicago a sollicit\u00e9 UL afin de disposer de r\u00e8gles claires pour garantir la s\u00e9curit\u00e9 dans la conception et la construction des panneaux de commande industriels. En r\u00e9ponse, des ing\u00e9nieurs de UL ont r\u00e9dig\u00e9 un premier document interne, non accessible au public, conserv\u00e9 dans les laboratoires UL\u2014litt\u00e9ralement dans les tiroirs des ing\u00e9nieurs, d\u2019o\u00f9 le terme \u00ab drawer standard \u00bb.<\/p>\n<hr data-start=\"1196\" data-end=\"1199\" \/>\n<h3 data-section-id=\"awhxnz\" data-start=\"393\" data-end=\"430\"><strong><u><span dir=\"auto\">Passage \u00e0 une norme publique<\/span><\/u><\/strong><span dir=\"auto\">\u00a0\u00a0<\/span><\/h3>\n<p data-start=\"1235\" data-end=\"1614\">Comme pour plusieurs documents UL d\u00e9velopp\u00e9s dans les ann\u00e9es 1970 et 1980, UL a ensuite entrepris de formaliser et publier ces normes internes. Par l\u2019interm\u00e9diaire de <strong data-start=\"1402\" data-end=\"1431\">UL Standards &amp; Engagement<\/strong>, ces documents ont d\u2019abord \u00e9t\u00e9 publi\u00e9s sous forme d\u2019<em data-start=\"1484\" data-end=\"1520\">\u00ab Outline of Investigation \u00bb (OOI)<\/em>, permettant \u00e0 d\u2019autres organismes de certification d\u2019appliquer les m\u00eames crit\u00e8res techniques.<\/p>\n<p data-start=\"1616\" data-end=\"1668\">Cette transition a eu lieu pour UL 508A en <strong data-start=\"1659\" data-end=\"1667\">1995<\/strong>.<\/p>\n<hr data-start=\"1670\" data-end=\"1673\" \/>\n<h3 data-section-id=\"awhxnz\" data-start=\"393\" data-end=\"430\"><strong><u><span dir=\"auto\">Publication officielle et \u00e9ditions<\/span><\/u><\/strong><span dir=\"auto\">\u00a0\u00a0<\/span><\/h3>\n<ul data-start=\"1715\" data-end=\"2075\">\n<li data-section-id=\"m62j7p\" data-start=\"1715\" data-end=\"1899\"><strong data-start=\"1717\" data-end=\"1734\">25 avril 2001<\/strong> \u2192 Premi\u00e8re \u00e9dition officielle de UL 508A, publi\u00e9e comme norme consensuelle, \u00e9labor\u00e9e par un comit\u00e9 technique compos\u00e9 d\u2019ing\u00e9nieurs issus de diff\u00e9rentes entreprises<\/li>\n<li data-section-id=\"9h7nau\" data-start=\"1900\" data-end=\"1960\"><strong data-start=\"1902\" data-end=\"1921\">31 juillet 2017<\/strong> \u2192 Publication de la deuxi\u00e8me \u00e9dition<\/li>\n<li data-section-id=\"8upwhw\" data-start=\"1961\" data-end=\"2075\"><strong data-start=\"1963\" data-end=\"1980\">24 avril 2018<\/strong> \u2192 Publication de la troisi\u00e8me \u00e9dition (actuellement en vigueur, avec mises \u00e0 jour ult\u00e9rieures)<\/li>\n<\/ul>\n<p data-start=\"2077\" data-end=\"2362\">Le <strong data-start=\"2080\" data-end=\"2096\">26 juin 2025<\/strong>, UL 508A (\u00e9dition 3) a \u00e9t\u00e9 reconnue comme <strong data-start=\"2139\" data-end=\"2176\">American National Standard (ANSI)<\/strong>. Cette d\u00e9signation atteste que la norme a \u00e9t\u00e9 \u00e9labor\u00e9e selon un processus ouvert, \u00e9quilibr\u00e9 et transparent, garantissant la prise en compte des int\u00e9r\u00eats de toutes les parties prenantes.<\/p>\n<hr data-start=\"2364\" data-end=\"2367\" \/>\n<h3 data-section-id=\"awhxnz\" data-start=\"393\" data-end=\"430\"><strong><u><span dir=\"auto\">Domaine d\u2019application et relations avec d\u2019autres normes<\/span><\/u><\/strong><span dir=\"auto\">\u00a0<\/span><\/h3>\n<p data-start=\"2430\" data-end=\"2641\">UL 508A s\u2019appuie sur les principes fondamentaux de s\u00e9curit\u00e9 \u00e9lectrique d\u00e9finis par le <strong data-start=\"2516\" data-end=\"2557\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">National Electrical Code (NEC)<\/span><\/span><\/strong> et s\u2019aligne avec les prescriptions de la <strong data-start=\"2599\" data-end=\"2640\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">NFPA 79<\/span><\/span><\/strong>.<\/p>\n<ul data-start=\"2643\" data-end=\"2881\">\n<li data-section-id=\"qr7zuy\" data-start=\"2643\" data-end=\"2761\"><strong data-start=\"2645\" data-end=\"2656\">NFPA 79<\/strong> concerne les <strong data-start=\"2670\" data-end=\"2710\">\u00e9quipements \u00e9lectriques des machines<\/strong> (\u00e0 l\u2019int\u00e9rieur comme \u00e0 l\u2019ext\u00e9rieur des panneaux)<\/li>\n<li data-section-id=\"wt4747\" data-start=\"2762\" data-end=\"2881\"><strong data-start=\"2764\" data-end=\"2775\">UL 508A<\/strong> se concentre sp\u00e9cifiquement sur la <strong data-start=\"2811\" data-end=\"2881\">conception et la construction des panneaux de commande industriels<\/strong><\/li>\n<\/ul>\n<p data-start=\"2883\" data-end=\"3125\">Une \u00e9volution majeure est intervenue vers <strong data-start=\"2925\" data-end=\"2933\">2005<\/strong>, avec l\u2019introduction du <strong data-start=\"2958\" data-end=\"2975\">Suppl\u00e9ment SB<\/strong>, qui fournit une m\u00e9thode normalis\u00e9e pour d\u00e9terminer le <strong data-start=\"3031\" data-end=\"3070\">Short-Circuit Current Rating (SCCR)<\/strong> des panneaux\u2014d\u00e9sormais un \u00e9l\u00e9ment central de la norme.<\/p>\n<hr data-start=\"3127\" data-end=\"3130\" \/>\n<h3 data-section-id=\"awhxnz\" data-start=\"393\" data-end=\"430\"><strong><u><span dir=\"auto\">Comparaison avec le cadre europ\u00e9en<\/span><\/u><\/strong><span dir=\"auto\">\u00a0<\/span><\/h3>\n<p data-start=\"3172\" data-end=\"3228\">Il n\u2019existe pas d\u2019\u00e9quivalent direct \u00e0 UL 508A en Europe.<\/p>\n<p data-start=\"3230\" data-end=\"3288\">On peut toutefois \u00e9tablir des correspondances partielles :<\/p>\n<ul data-start=\"3290\" data-end=\"3520\">\n<li data-section-id=\"3yfat6\" data-start=\"3290\" data-end=\"3419\"><strong data-start=\"3292\" data-end=\"3333\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">IEC 61439-2<\/span><\/span><\/strong> \u2192 comparable \u00e0 <strong data-start=\"3349\" data-end=\"3390\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">UL 891<\/span><\/span><\/strong> (tableaux de distribution)<\/li>\n<li data-section-id=\"135t8wi\" data-start=\"3420\" data-end=\"3520\"><strong data-start=\"3422\" data-end=\"3463\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">IEC 60204-1<\/span><\/span><\/strong> \u2192 comparable \u00e0 <strong data-start=\"3479\" data-end=\"3520\"><span class=\"hover:entity-accent entity-underline inline cursor-pointer align-baseline\"><span class=\"whitespace-normal\">NFPA 79<\/span><\/span><\/strong><\/li>\n<\/ul>\n<p data-start=\"3522\" data-end=\"3729\">Contrairement \u00e0 l\u2019approche IEC, UL 508A se distingue par une approche <strong data-start=\"3592\" data-end=\"3608\">prescriptive<\/strong>, centr\u00e9e sur les r\u00e8gles de construction des panneaux, plut\u00f4t que sur une validation globale des performances du syst\u00e8me.<\/p>\n<\/div>            <\/div>\n        \n        \n                <div class=\"clear-both\"><\/div>\n        \n\n    <\/div>\n        <\/section>\n\n    \n\n\n\n\n    \n        <section\n            data-name=\"Contenuto testuale con immagine\"\n            class=\"bow-gte-testo-media u-spacer-base\"\n            id=\"\"\n        >\n            \n<div class=\"o-text-media px-side-spacer sm:px-side-spacer-sm lg:px-side-spacer-tablet 2xl:px-side-spacer-desktop flex flex-wrap items-start md:block\">\n\n    \n                    <div class=\"mb-6 relative w-full md:mb-4 lg:mb-8 xl:mb-9\">\n                \n        <div                class=\"m-headings\"\n            >\n    \n    \n<h2 class=\"a-heading text-left text-primary font-heading text-lg lg:text-xl font-normal mt-2 first:mt-0\">\n                    MISE \u00e0 JOUR DE JUIN 2025    <\/h2>\n        <\/div>\n                <\/div>\n        \n        \n                    <div class=\"relative w-full\">\n                \n<div class=\"a-text font-text text-base normal mt-8 first:mt-0 space-y-4\">\n    <p><strong><u><span dir=\"auto\">Une nouvelle mise \u00e0 jour de la norme a \u00e9t\u00e9 officiellement publi\u00e9e le 26 juin 2025.<\/span><\/u><\/strong><span dir=\"auto\">\u00a0\u00a0En tant que membres du comit\u00e9 UL 508A, nous vous donnons ci-apr\u00e8s un aper\u00e7u des principaux changements.<\/span><\/p>\n<\/div>            <\/div>\n        \n        \n                <div class=\"clear-both\"><\/div>\n        \n\n    <\/div>\n        <\/section>\n\n    \n\n\n\n\n    \n        <section\n            data-name=\"Contenuto testuale con immagine\"\n            class=\"bow-gte-testo-media u-spacer-2xs\"\n            id=\"\"\n        >\n            \n<div class=\"o-text-media px-side-spacer sm:px-side-spacer-sm lg:px-side-spacer-tablet 2xl:px-side-spacer-desktop flex flex-wrap items-start md:block\">\n\n    \n                    <div class=\"mb-6 relative w-full md:mb-4 lg:mb-8 xl:mb-9\">\n                \n        <div                class=\"m-headings\"\n            >\n    \n    \n<h2 class=\"a-heading text-primary font-heading text-lg lg:text-xl font-normal mt-2 first:mt-0\">\n                    Limites des tensions des circuits de commande ; \u00a7 66.12.1 et \u00a7 66.12.2    <\/h2>\n        <\/div>\n                <\/div>\n        \n        \n                    <div class=\"relative w-full\">\n                \n<div class=\"a-text font-text text-base normal mt-8 first:mt-0 space-y-4\">\n    <p><span dir=\"auto\">La raison de ce changement est d&rsquo;aligner les exigences de la norme UL 508A sur celles de la norme NFPA 79. La limite de tension maximale pour les circuits de commande est d\u00e9sormais fix\u00e9e \u00e0 120 Vca ou 250 Vcc.<\/span><\/p>\n<p><span dir=\"auto\">Des prescriptions similaires sont \u00e9galement pr\u00e9sentes dans la norme IEC 60204-1, m\u00eame si les limites sont plus \u00e9lev\u00e9es.<\/span><\/p>\n<\/div>            <\/div>\n        \n        \n                <div class=\"clear-both\"><\/div>\n        \n\n    <\/div>\n        <\/section>\n\n    \n\n\n\n\n    \n        <section\n            data-name=\"Contenuto testuale con immagine\"\n            class=\"bow-gte-testo-media u-spacer-2xs\"\n            id=\"\"\n        >\n            \n<div class=\"o-text-media px-side-spacer sm:px-side-spacer-sm lg:px-side-spacer-tablet 2xl:px-side-spacer-desktop flex flex-wrap items-start md:block\">\n\n    \n                    <div class=\"mb-6 relative w-full md:mb-4 lg:mb-8 xl:mb-9\">\n                \n        <div                class=\"m-headings\"\n            >\n    \n    \n<h2 class=\"a-heading text-primary font-heading text-lg lg:text-xl font-normal mt-2 first:mt-0\">\n                    N\u00e9cessit\u00e9 d&rsquo;une fonction d&rsquo;arr\u00eat d&rsquo;urgence ; \u00a7 66.11.2    <\/h2>\n        <\/div>\n                <\/div>\n        \n        \n                    <div class=\"relative w-full\">\n                \n<div class=\"a-text font-text text-base normal mt-8 first:mt-0 space-y-4\">\n    <p><span dir=\"auto\">Par le pass\u00e9, la norme UL 508A exigeait l&rsquo;installation d&rsquo;un bouton d&rsquo;arr\u00eat d&rsquo;urgence sur chaque panneau de commande industriel des machines \u00e9quip\u00e9es de commandes op\u00e9rateur, telles que des boutons-poussoirs. La norme NFPA 79 pr\u00e9cise qu&rsquo;un arr\u00eat d&rsquo;urgence est requis lorsqu&rsquo;une \u00e9valuation des risques l&rsquo;indique, une approche \u00e9galement adopt\u00e9e par la norme B11.19. La norme ISO 13850, r\u00e9f\u00e9renc\u00e9e dans la norme NFPA 79, suit une philosophie similaire.<\/span><\/p>\n<p><span dir=\"auto\">La proposition aligne la norme UL 508A sur cette approche.<\/span><\/p>\n<p><em><span dir=\"auto\">[UL 508A: 2025]\u00a0<\/span><strong><span dir=\"auto\">66.11 Commandes de l&rsquo;op\u00e9rateur<\/span><\/strong><\/em><\/p>\n<p><em><span dir=\"auto\">66.11.2 Un panneau de commande industriel \u00e9quip\u00e9 de commandes d&rsquo;op\u00e9rateur, telles que des boutons-poussoirs et des s\u00e9lecteurs,\u00a0<\/span><u><span dir=\"auto\">peut \u00eatre \u00e9quip\u00e9 d&rsquo;un bouton d&rsquo;arr\u00eat d&rsquo;urgence.<\/span><\/u><\/em><\/p>\n<\/div>            <\/div>\n        \n        \n                <div class=\"clear-both\"><\/div>\n        \n\n    <\/div>\n        <\/section>\n\n    \n\n\n\n\n    \n        <section\n            data-name=\"Contenuto testuale con immagine\"\n            class=\"bow-gte-testo-media u-spacer-2xs\"\n            id=\"\"\n        >\n            \n<div class=\"o-text-media px-side-spacer sm:px-side-spacer-sm lg:px-side-spacer-tablet 2xl:px-side-spacer-desktop flex flex-wrap items-start md:block\">\n\n    \n                    <div class=\"mb-6 relative w-full md:mb-4 lg:mb-8 xl:mb-9\">\n                \n        <div                class=\"m-headings\"\n            >\n    \n    \n<h2 class=\"a-heading text-primary font-heading text-lg lg:text-xl font-normal mt-2 first:mt-0\">\n                    Dispositifs de d\u00e9connexion \u2013 Machines industrielles ; 66.6.1, 66.6.1A, tableau 52.1    <\/h2>\n        <\/div>\n                <\/div>\n        \n        \n                    <div class=\"relative w-full\">\n                \n<div class=\"a-text font-text text-base normal mt-8 first:mt-0 space-y-4\">\n    <p><span dir=\"auto\">Par le pass\u00e9, tous les panneaux de commande industriels (PCI) des machines industrielles devaient\u00a0<\/span><strong><span dir=\"auto\">\u00eatre \u00e9quip\u00e9s d&rsquo;une poign\u00e9e externe reli\u00e9e \u00e0 un dispositif de d\u00e9connexion<\/span><\/strong><span dir=\"auto\">\u00a0pour chaque source d&rsquo;alimentation. Cependant, il arrive que plusieurs panneaux alimentent une m\u00eame machine via une seule ligne d&rsquo;alimentation externe.<\/span><\/p>\n<p><span dir=\"auto\">L&rsquo;\u00e9dition 2021 de\u00a0<\/span><strong><span dir=\"auto\">la norme NFPA 79 \u2013 Norme pour les machines industrielles \u2013<\/span><\/strong><span dir=\"auto\">\u00a0exige d\u00e9sormais un dispositif de sectionnement avec une poign\u00e9e de commande externe\u00a0<\/span><strong><span dir=\"auto\">pour chaque\u00a0<\/span><em><span dir=\"auto\">circuit d&rsquo;alimentation de la machine<\/span><\/em><\/strong><span dir=\"auto\">\u00a0. Outre le dispositif de sectionnement du circuit d&rsquo;alimentation principal de la machine, des dispositifs suppl\u00e9mentaires peuvent \u00eatre pr\u00e9vus pour d\u00e9connecter les \u00e9quipements \u00e9lectriques afin de pouvoir intervenir sur des parties individuelles de la machine. Mais ce n&rsquo;est pas obligatoire\u00a0!<\/span><\/p>\n<p><span dir=\"auto\">Conform\u00e9ment \u00e0 ces exigences, les tableaux faisant partie d&rsquo;un groupe commandant une seule machine peuvent \u00eatre aliment\u00e9s par un tableau contenant le dispositif de sectionnement du circuit d&rsquo;alimentation de la machine. Dans ce cas, ces tableaux auxiliaires sont autoris\u00e9s, mais non obligatoires, \u00e0 disposer de leur propre dispositif de sectionnement. Si un tel dispositif de sectionnement est pr\u00e9vu, il ne n\u00e9cessite pas de poign\u00e9e de commande externe.<\/span><\/p>\n<p><span dir=\"auto\">Avec cette r\u00e9vision,\u00a0<\/span><strong><span dir=\"auto\">la norme UL 508A<\/span><\/strong><span dir=\"auto\">\u00a0s\u2019aligne sur la m\u00eame approche que\u00a0<\/span><strong><span dir=\"auto\">la norme NFPA 79<\/span><\/strong><span dir=\"auto\">\u00a0.<\/span><\/p>\n<\/div>            <\/div>\n        \n        \n                <div class=\"clear-both\"><\/div>\n        \n\n    <\/div>\n        <\/section>\n\n    \n\n\n\n\n    \n        <section\n            data-name=\"Contenuto testuale con immagine\"\n            class=\"bow-gte-testo-media u-spacer-2xs\"\n            id=\"\"\n        >\n            \n<div class=\"o-text-media px-side-spacer sm:px-side-spacer-sm lg:px-side-spacer-tablet 2xl:px-side-spacer-desktop flex flex-wrap items-start md:block\">\n\n    \n                    <div class=\"mb-6 relative w-full md:mb-4 lg:mb-8 xl:mb-9\">\n                \n        <div                class=\"m-headings\"\n            >\n    \n    \n<h2 class=\"a-heading text-primary font-heading text-lg lg:text-xl font-normal mt-2 first:mt-0\">\n                    Emplacement de l&rsquo;ouverture de ventilation ; 21.2.2 et Figure 21.1    <\/h2>\n        <\/div>\n                <\/div>\n        \n        \n                    <div class=\"relative w-full\">\n                \n<div class=\"a-text font-text text-base normal mt-8 first:mt-0 space-y-4\">\n    <p><span dir=\"auto\">Les panneaux, qui incluent des variateurs, doivent souvent \u00eatre \u00e9quip\u00e9s de ventilateurs pour assurer un flux d&rsquo;air positif et refroidir les dissipateurs thermiques. Ces panneaux sont install\u00e9s avec d&rsquo;autres panneaux situ\u00e9s de chaque c\u00f4t\u00e9, ce qui limite les zones o\u00f9 l&rsquo;air sortant peut \u00eatre dirig\u00e9. Dans ce cas, l&rsquo;avant du panneau doit \u00eatre utilis\u00e9 pour les ouvertures de ventilation. L&rsquo;exigence de la section 21.2.2 s&rsquo;applique d\u00e8s qu&rsquo;un bouton de commande, un commutateur IHM ou une poign\u00e9e est mont\u00e9 \u00e0 l&rsquo;avant du panneau, quel que soit le degr\u00e9 d&rsquo;interaction de l&rsquo;op\u00e9rateur. Cette exigence ne traite d&rsquo;aucun danger sp\u00e9cifique, mais vise uniquement \u00e0 interdire que l&rsquo;air sortant soit dirig\u00e9 vers une zone suppos\u00e9e occup\u00e9e par un op\u00e9rateur. Pour les panneaux fonctionnant en conditions normales, l&rsquo;air sortant des dissipateurs thermiques des semi-conducteurs ne pr\u00e9sente aucun danger pour l&rsquo;op\u00e9rateur.<\/span><\/p>\n<p><span dir=\"auto\">Le changement aborde et assouplit cette prescription, en ajoutant l\u2019exception suivante :<\/span><\/p>\n<p><span dir=\"auto\">[UL 508A: 2025]\u00a0<\/span><strong><em><span dir=\"auto\">21.2 Emplacement de l&rsquo;ouverture de ventilation<\/span><\/em><\/strong><\/p>\n<p><strong><em><span dir=\"auto\">Exception n\u00b0 3 :<\/span><\/em><\/strong><em><span dir=\"auto\">\u00a0Un bo\u00eetier contenant des actionneurs de commutation ou\u00a0<\/span><strong><span dir=\"auto\">des affichages externes qui ne n\u00e9cessitent qu&rsquo;une courte pr\u00e9sence d&rsquo;un op\u00e9rateur<\/span><\/strong><span dir=\"auto\">\u00a0, tels que des poign\u00e9es pour des moyens de d\u00e9connexion, des boutons d&rsquo;arr\u00eat d&rsquo;urgence, des boutons de r\u00e9initialisation de surcharge externes, des dispositifs de commande simples (tels que des boutons-poussoirs de marche\/arr\u00eat, des commutateurs s\u00e9lecteurs), des voyants lumineux, des affichages num\u00e9riques non interactifs, des faces de compteurs \u00e9lectriques et des dispositifs similaires,\u00a0<\/span><strong><span dir=\"auto\">n&rsquo;est pas tenu de se conformer \u00e0 21.2.2.<\/span><\/strong><\/em><\/p>\n<\/div>            <\/div>\n        \n        \n                <div class=\"clear-both\"><\/div>\n        \n\n    <\/div>\n        <\/section>\n\n    \n","protected":false},"excerpt":{"rendered":"<p>UL 508A est la norme de produit pour les panneaux de contr\u00f4le industriels aux \u00c9tats-Unis, c&rsquo;est-\u00e0-dire les panneaux \u00e9lectriques qui contr\u00f4lent les machines.<\/p>\n","protected":false},"author":1,"featured_media":50070,"parent":0,"menu_order":2,"template":"","meta":{"_acf_changed":false,"footnotes":""},"normative-tecniche":[167],"class_list":["post-39459","normativa_tecnica","type-normativa_tecnica","status-publish","has-post-thumbnail","hentry","tipologia_normativa-normes-americaine"],"acf":{"sottotitolo":"Norme pour les panneaux de contr\u00f4le industriels","allegati":null},"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.2 - 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