{"id":29895,"date":"2026-07-08T16:16:07","date_gmt":"2026-07-08T08:16:07","guid":{"rendered":"https:\/\/www.cnspd.com\/?p=29895"},"modified":"2026-07-09T16:09:58","modified_gmt":"2026-07-09T08:09:58","slug":"plc-i-o-signal-surge-protection-for-industrial-control-panels","status":"publish","type":"post","link":"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/","title":{"rendered":"Protection contre les surtensions des signaux d'E\/S PLC pour panneaux de contr\u00f4le industriels"},"content":{"rendered":"<div data-elementor-type=\"wp-post\" data-elementor-id=\"29895\" class=\"elementor elementor-29895\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-d0d6290 e-flex e-con-boxed e-con e-parent\" data-id=\"d0d6290\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a00e48c elementor-widget elementor-widget-html\" data-id=\"a00e48c\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"html.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<style>\r\n  .leeyee-plc-signal-article {\r\n    --leeyee-blue: #004898;\r\n    --leeyee-blue-dark: #00346f;\r\n    --leeyee-soft-blue: #f4f8ff;\r\n    --leeyee-soft-border: #dbe8f7;\r\n    --leeyee-text: #1f2933;\r\n    --leeyee-muted: #5d6b7a;\r\n    --leeyee-warning: #fff8ea;\r\n    --leeyee-warning-border: #f3d58a;\r\n    max-width: 860px;\r\n    margin: 0 auto;\r\n    padding: 20px 18px 64px;\r\n    color: var(--leeyee-text);\r\n    font-size: 16.5px;\r\n    line-height: 1.72;\r\n  }\r\n\r\n  .leeyee-plc-signal-article * {\r\n    box-sizing: border-box;\r\n  }\r\n\r\n  .leeyee-plc-signal-article p {\r\n    margin: 0 0 16px;\r\n  }\r\n\r\n  .leeyee-plc-signal-article a {\r\n    color: var(--leeyee-blue);\r\n    text-decoration: none;\r\n    font-weight: 600;\r\n  }\r\n\r\n  .leeyee-plc-signal-article a:hover {\r\n  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10px 0;\r\n    padding: 12px 14px;\r\n    border: 1px solid var(--leeyee-soft-border);\r\n    border-radius: 12px;\r\n    background: #ffffff;\r\n  }\r\n\r\n  .leeyee-button-row {\r\n    display: flex;\r\n    flex-wrap: wrap;\r\n    gap: 12px;\r\n    margin-top: 18px;\r\n  }\r\n\r\n  .leeyee-plc-signal-article button.leeyee-site-popup-btn,\r\n  .leeyee-plc-signal-article button.leeyee-site-popup-btn:hover,\r\n  .leeyee-plc-signal-article button.leeyee-site-popup-btn:focus,\r\n  .leeyee-plc-signal-article button.leeyee-site-popup-btn:active,\r\n  .leeyee-plc-signal-article button.leeyee-inquiry-btn,\r\n  .leeyee-plc-signal-article button.leeyee-inquiry-btn:hover,\r\n  .leeyee-plc-signal-article button.leeyee-inquiry-btn:focus,\r\n  .leeyee-plc-signal-article button.leeyee-inquiry-btn:active {\r\n    display: inline-flex !important;\r\n    align-items: center !important;\r\n    justify-content: center !important;\r\n    min-width: 210px !important;\r\n    min-height: 48px !important;\r\n 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.leeyee-plc-signal-article a.leeyee-article-btn,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn:link,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn:visited,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn:hover,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn:focus,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn:active {\r\n    display: inline-flex !important;\r\n    align-items: center !important;\r\n    justify-content: center !important;\r\n    min-width: 190px !important;\r\n    min-height: 46px !important;\r\n    padding: 12px 18px !important;\r\n    border-radius: 999px !important;\r\n    background: #004898 !important;\r\n    border: 1px solid #004898 !important;\r\n    color: #ffffff !important;\r\n    -webkit-text-fill-color: #ffffff !important;\r\n    font-size: 15px !important;\r\n    font-weight: 800 !important;\r\n    line-height: 1.2 !important;\r\n    text-align: center !important;\r\n    text-decoration: none !important;\r\n    opacity: 1 !important;\r\n    visibility: visible !important;\r\n    white-space: nowrap !important;\r\n    cursor: pointer !important;\r\n    position: relative !important;\r\n    z-index: 2 !important;\r\n    overflow: visible !important;\r\n    text-indent: 0 !important;\r\n    box-shadow: none !important;\r\n  }\r\n\r\n  .leeyee-plc-signal-article a.leeyee-article-btn:hover {\r\n    background: #00346f !important;\r\n    border-color: #00346f !important;\r\n    color: #ffffff !important;\r\n    -webkit-text-fill-color: #ffffff !important;\r\n    text-decoration: none !important;\r\n  }\r\n\r\n  .leeyee-plc-signal-article a.leeyee-article-btn span {\r\n    display: inline-block !important;\r\n    color: #ffffff !important;\r\n    -webkit-text-fill-color: #ffffff !important;\r\n    font-size: 15px !important;\r\n    font-weight: 800 !important;\r\n    line-height: 1.2 !important;\r\n    opacity: 1 !important;\r\n    visibility: visible !important;\r\n    white-space: nowrap !important;\r\n    text-indent: 0 !important;\r\n    position: relative !important;\r\n    z-index: 5 !important;\r\n    text-decoration: none !important;\r\n  }\r\n\r\n  .leeyee-plc-signal-article a.leeyee-article-btn.secondary,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn.secondary:link,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn.secondary:visited,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn.secondary:hover,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn.secondary:focus,\r\n  .leeyee-plc-signal-article a.leeyee-article-btn.secondary:active {\r\n    background: #ffffff !important;\r\n    color: #004898 !important;\r\n    -webkit-text-fill-color: #004898 !important;\r\n    border-color: #bcd2ee !important;\r\n  }\r\n\r\n  .leeyee-plc-signal-article a.leeyee-article-btn.secondary span {\r\n    color: #004898 !important;\r\n    -webkit-text-fill-color: #004898 !important;\r\n  }\r\n\r\n  .leeyee-plc-signal-article a.leeyee-article-btn.secondary:hover {\r\n    background: #f4f8ff !important;\r\n    color: #004898 !important;\r\n    -webkit-text-fill-color: #004898 !important;\r\n    border-color: #004898 !important;\r\n    text-decoration: none !important;\r\n  }\r\n\r\n  .leeyee-faq {\r\n    margin: 28px 0 0;\r\n  }\r\n\r\n  .leeyee-faq details {\r\n    margin: 12px 0;\r\n    padding: 16px 18px;\r\n    border: 1px solid var(--leeyee-soft-border);\r\n    border-radius: 14px;\r\n    background: #ffffff;\r\n  }\r\n\r\n  .leeyee-faq summary {\r\n    cursor: pointer;\r\n    font-weight: 800;\r\n    color: #172536;\r\n  }\r\n\r\n  .leeyee-faq details p {\r\n    margin-top: 12px;\r\n    margin-bottom: 0;\r\n  }\r\n\r\n  @media (max-width: 768px) {\r\n    .leeyee-plc-signal-article {\r\n      padding: 14px 14px 44px;\r\n      font-size: 15.8px;\r\n      line-height: 1.68;\r\n    }\r\n\r\n    .leeyee-plc-signal-article h2 {\r\n      margin-top: 34px;\r\n      font-size: 25px;\r\n      line-height: 1.3;\r\n    }\r\n\r\n    .leeyee-plc-signal-article h3 {\r\n      font-size: 20px;\r\n    }\r\n\r\n    .leeyee-article-intro,\r\n    .leeyee-quick-answer,\r\n    .leeyee-note-box,\r\n    .leeyee-warning-box,\r\n    .leeyee-check-box,\r\n    .leeyee-product-box,\r\n    .leeyee-cta-box {\r\n      padding: 18px 16px;\r\n      border-radius: 15px;\r\n    }\r\n\r\n    .leeyee-article-intro .lead {\r\n      font-size: 18px;\r\n    }\r\n\r\n    .leeyee-article-figure {\r\n      margin: 22px 0 28px;\r\n      border-radius: 14px;\r\n    }\r\n\r\n    .leeyee-article-figure figcaption {\r\n      padding: 10px 12px;\r\n      font-size: 13px;\r\n    }\r\n\r\n    .leeyee-two-col {\r\n      grid-template-columns: 1fr;\r\n      gap: 14px;\r\n    }\r\n\r\n    .leeyee-table {\r\n      min-width: 680px;\r\n      font-size: 14px;\r\n    }\r\n\r\n    .leeyee-table th,\r\n    .leeyee-table td {\r\n      padding: 11px 12px;\r\n    }\r\n\r\n    .leeyee-step {\r\n      padding: 16px 16px 16px 58px;\r\n    }\r\n\r\n    .leeyee-button-row {\r\n      flex-direction: column;\r\n    }\r\n\r\n    .leeyee-plc-signal-article button.leeyee-site-popup-btn,\r\n    .leeyee-plc-signal-article button.leeyee-inquiry-btn,\r\n    .leeyee-plc-signal-article a.leeyee-article-btn {\r\n      width: 100% !important;\r\n      min-width: 100% !important;\r\n      white-space: normal !important;\r\n    }\r\n\r\n    .leeyee-plc-signal-article button.leeyee-site-popup-btn span,\r\n    .leeyee-plc-signal-article button.leeyee-site-popup-btn .w-btn-label,\r\n    .leeyee-plc-signal-article button.leeyee-inquiry-btn span,\r\n    .leeyee-plc-signal-article button.leeyee-inquiry-btn .w-btn-label,\r\n    .leeyee-plc-signal-article a.leeyee-article-btn span {\r\n      white-space: normal !important;\r\n    }\r\n  }\r\n<\/style>\r\n\r\n<article class=\"leeyee-plc-signal-article\">\r\n\r\n  <div class=\"leeyee-article-kicker\">Guide technique pour les panneaux de contr\u00f4le PLC<\/div>\r\n\r\n  <section class=\"leeyee-article-intro\">\r\n    <p class=\"lead\">Un coffret PLC peut d\u00e9j\u00e0 avoir un dispositif de protection contre les surtensions AC \u00e0 l'entr\u00e9e d'alimentation, mais cela ne prot\u00e8ge pas automatiquement les bornes de signal PLC.<\/p>\r\n    <p>De nombreuses d\u00e9faillances de PLC surviennent par les lignes \u201c petites \u201d : entr\u00e9e num\u00e9rique, sortie num\u00e9rique, entr\u00e9e analogique, sortie analogique, RS485, boucle 4-20mA, c\u00e2ble de capteur, c\u00e2ble E\/S \u00e0 distance et c\u00e2blage d'appareils de terrain.<\/p>\r\n    <p>Ce guide explique quand les lignes E\/S et de signal PLC ont besoin de protection contre les surtensions, comment choisir un SPD de signal appropri\u00e9 et quelles informations les fabricants de panneaux ou les acheteurs OEM doivent confirmer avant de commander.<\/p>\r\n  <\/section>\r\n\r\n  <section class=\"leeyee-quick-answer\">\r\n    <div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table des mati\u00e8res<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#quick-answer\" >R\u00e9ponse rapide<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#why-plc-signal-lines-need-surge-protection\" >Pourquoi les lignes de signal PLC ont besoin de protection contre les surtensions<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#plc-io-surge-protection-which-lines-need-signal-spd\" >Protection contre les surtensions pour les E\/S PLC : quelles lignes ont besoin d'un SPD pour signal ?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#do-you-need-surge-protection-on-every-plc-io-point\" >Avez-vous besoin d'une protection contre les surtensions sur chaque point E\/S PLC ?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#signal-spd-vs-spd-remote-alarm-contact\" >SPD de signal vs contact d'alarme \u00e0 distance SPD<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#signal-spd-selection-for-plc-dido-aiao-rs485-and-4-20ma-lines\" >S\u00e9lection de SPD de signal pour lignes PLC DI\/DO, AI\/AO, RS485 et 4-20mA<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#recommended-selection-by-plc-signal-type\" >S\u00e9lection recommand\u00e9e par type de signal PLC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#plc-signal-spd-parameter-matrix\" >Matrice des param\u00e8tres SPD de signal PLC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#recommended-leeyee-signal-spd-for-plc-and-rs485-lines\" >SPD de signal LEEYEE recommand\u00e9 pour les lignes PLC et RS485<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#where-should-the-signal-spd-be-installed\" >O\u00f9 le SPD de signal doit-il \u00eatre install\u00e9 ?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#what-happens-if-plc-signal-lines-are-not-protected\" >Que se passe-t-il si les lignes de signal PLC ne sont pas prot\u00e9g\u00e9es ?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#before-ordering-signal-spd-for-plc-panels\" >Avant de commander un SPD de signal pour les panneaux PLC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#common-selection-mistakes\" >Erreurs courantes de s\u00e9lection<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#related-reading\" >Lectures connexes<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#faq-plc-io-signal-surge-protection\" >FAQ : Protection contre les surtensions des signaux E\/S PLC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/#need-help-choosing-signal-spd-for-a-plc-control-panel\" >Besoin d'aide pour choisir un SPD de signal pour un panneau de contr\u00f4le PLC ?<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"quick-answer\"><\/span>R\u00e9ponse rapide<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n    <p><strong>Utilisez une protection contre les surtensions pour les E\/S PLC et les lignes de communication lorsque le c\u00e2ble quitte le coffret de contr\u00f4le, fonctionne \u00e0 l'ext\u00e9rieur, se connecte \u00e0 des instruments de terrain, traverse des machines ou des b\u00e2timents, ou est install\u00e9 pr\u00e8s de moteurs, variateurs de fr\u00e9quence, pompes, sol\u00e9no\u00efdes ou longs c\u00e2bles d'alimentation.<\/strong><\/p>\r\n    <p>Un SPD AC de type 2 prot\u00e8ge l'entr\u00e9e d'alimentation du coffret. Un SPD de signal prot\u00e8ge le chemin basse tension entrant dans la borne PLC. Ce sont des points de protection diff\u00e9rents et ne doivent pas se remplacer l'un l'autre.<\/p>\r\n    <p>Pour les circuits de signal, de donn\u00e9es et de communication, la s\u00e9lection SPD est normalement consid\u00e9r\u00e9e sous le champ de protection contre les surtensions de signal, couramment r\u00e9f\u00e9renc\u00e9e par la norme IEC 61643-21, plut\u00f4t que par les r\u00e8gles de s\u00e9lection SPD pour l'alimentation AC.<\/p>\r\n  <\/section>\r\n\r\n  <figure class=\"leeyee-article-figure\">\r\n    <img src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/plc-control-panel-signal-surge-protection-architecture-scaled.webp\" alt=\"PLC control panel signal surge protection architecture for AC power 24VDC control power RS485 sensor and I O lines\" loading=\"lazy\" decoding=\"async\">\r\n    <figcaption>La protection contre les surtensions du panneau de contr\u00f4le PLC doit s\u00e9parer la protection c\u00f4t\u00e9 alimentation, la protection de l'alimentation de contr\u00f4le 24V DC et la protection de ligne de signal.<\/figcaption>\r\n  <\/figure>\r\n\r\n  <div class=\"leeyee-table-wrap\">\r\n    <table class=\"leeyee-table\">\r\n      <thead>\r\n        <tr>\r\n          <th>Ligne PLC<\/th>\r\n          <th>Exemple typique<\/th>\r\n          <th>Quand la protection SPD de signal est recommand\u00e9e<\/th>\r\n          <th>Signification pour l'Acheteur<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td>DI \\\/ DO<\/td>\r\n          <td>Entr\u00e9e num\u00e9rique 24V, sortie relais, signal d'\u00e9tat de la machine<\/td>\r\n          <td>Long c\u00e2blage de terrain, \u00e9quipements ext\u00e9rieurs, charges inductives, sections de machine s\u00e9par\u00e9es<\/td>\r\n          <td>Prot\u00e8ge les bornes I\/O du PLC des surtensions transitoires entrant par les fils de terrain.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>AI \\\/ AO<\/td>\r\n          <td>Boucle de transmetteur 0-10V, 4-20mA<\/td>\r\n          <td>Le capteur ou le transmetteur est \u00e0 l'ext\u00e9rieur du bo\u00eetier ou le c\u00e2ble est expos\u00e9 \u00e0 un couplage de surtensions.<\/td>\r\n          <td>Aide \u00e0 r\u00e9duire les dommages et les lectures instables sur les modules analogiques.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>RS485 \/ Modbus RTU<\/td>\r\n          <td>PLC vers compteur, onduleur, I\/O distant, appareil SCADA<\/td>\r\n          <td>Long c\u00e2ble bus, RS485 ext\u00e9rieur, multiples armoires, diff\u00e9rentes zones de mise \u00e0 la terre<\/td>\r\n          <td>Prot\u00e8ge les ports de communication sans utiliser une SPD d'alimentation AC sur une ligne de donn\u00e9es.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Ligne de capteur<\/td>\r\n          <td>Capteur de proximit\u00e9, capteur de pression, capteur de niveau, d\u00e9bitm\u00e8tre<\/td>\r\n          <td>Le c\u00e2ble du capteur court le long des plateaux de terrain, pr\u00e8s des moteurs ou \u00e0 l'ext\u00e9rieur de la zone prot\u00e9g\u00e9e du bo\u00eetier.<\/td>\r\n          <td>Prot\u00e8ge le chemin du signal faible avant qu'il n'atteigne les terminaux d'entr\u00e9e PLC.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>C\u00e2ble de dispositif de terrain<\/td>\r\n          <td>Actionneur de vanne, signal de pompe, statut d'\u00e9quipement \u00e0 distance<\/td>\r\n          <td>Le c\u00e2ble connecte l'\u00e9quipement dans une autre zone, un autre cabinet ou une zone ext\u00e9rieure<\/td>\r\n          <td>R\u00e9duit le risque de surtension d\u00fb \u00e0 une diff\u00e9rence de potentiel au sol et aux transitoires induits.<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"why-plc-signal-lines-need-surge-protection\"><\/span>Pourquoi les lignes de signal PLC ont besoin de protection contre les surtensions<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>Un panneau de contr\u00f4le PLC n'est pas prot\u00e9g\u00e9 uniquement par son c\u00e2ble d'alimentation entrant. L'\u00e9nergie de surtension peut entrer par tout chemin conducteur connect\u00e9 au syst\u00e8me PLC.<\/p>\r\n\r\n  <p>Pour les panneaux de contr\u00f4le industriels, les chemins les plus courants sont :<\/p>\r\n\r\n  <ul>\r\n    <li>Alimentation AC entrant dans le cabinet de contr\u00f4le.<\/li>\r\n    <li>Bus de puissance de contr\u00f4le 24VDC \u00e0 l'int\u00e9rieur du cabinet.<\/li>\r\n    <li>C\u00e2blage d'entr\u00e9e\/sortie PLC connect\u00e9 aux dispositifs de terrain.<\/li>\r\n    <li>Lignes RS485, Modbus RTU, t\u00e9l\u00e9m\u00e9trie et surveillance \u00e0 distance.<\/li>\r\n    <li>C\u00e2bles de capteurs et d'instruments ext\u00e9rieurs au tableau.<\/li>\r\n  <\/ul>\r\n\r\n  <p>C'est pourquoi un armoire de contr\u00f4le peut n\u00e9cessiter \u00e0 la fois des SPD d'alimentation et des SPD de signal. Le SPD d'alimentation g\u00e8re l'\u00e9nergie de surtension du c\u00f4t\u00e9 de l'alimentation. Le SPD de signal traite les surtensions transitoires du c\u00f4t\u00e9 de contr\u00f4le ou de communication basse tension.<\/p>\r\n\r\n  <div class=\"leeyee-warning-box\">\r\n    <h3>Important : Un SPD AC ne prot\u00e8ge pas chaque terminal PLC.<\/h3>\r\n    <p>Si un c\u00e2ble de capteur de 50 m\u00e8tres entre dans l'armoire et se connecte directement \u00e0 un module d'entr\u00e9e PLC, une surtension induite sur ce c\u00e2ble peut atteindre le PLC avant que le SPD AC ait la moindre chance d'intervenir.<\/p>\r\n    <p>Pour cette raison, les SPD de signal doivent \u00eatre envisag\u00e9s au point d'entr\u00e9e des c\u00e2bles de terrain, notamment lorsque les c\u00e2bles sont longs, en ext\u00e9rieur, expos\u00e9s ou connect\u00e9s \u00e0 des \u00e9quipements distants.<\/p>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"plc-io-surge-protection-which-lines-need-signal-spd\"><\/span>Protection contre les surtensions pour les E\/S PLC : quelles lignes ont besoin d'un SPD pour signal ?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>Tous les petits fils de signal n'ont pas besoin d'un SPD s\u00e9par\u00e9. La bonne d\u00e9cision d\u00e9pend du trajet du c\u00e2ble, de l'exposition, de l'environnement d'installation, de l'importance du syst\u00e8me et des sp\u00e9cifications du projet.<\/p>\r\n\r\n  <div class=\"leeyee-two-col\">\r\n    <div class=\"leeyee-mini-card\">\r\n      <span class=\"leeyee-small-label\">Risque \u00e9lev\u00e9<\/span>\r\n      <h3>Valeur g\u00e9n\u00e9ralement \u00e0 prot\u00e9ger<\/h3>\r\n      <ul>\r\n        <li>Capteurs et transmetteurs ext\u00e9rieurs.<\/li>\r\n        <li>Lignes de bus RS485 entre les armoires.<\/li>\r\n        <li>C\u00e2bles I\/O \u00e0 distance.<\/li>\r\n        <li>Boucles 4-20mA provenant des instruments de terrain.<\/li>\r\n        <li>C\u00e2bles de signal pr\u00e8s de VFD, moteurs, pompes ou c\u00e2bles d'alimentation longs.<\/li>\r\n        <li>Lignes de contr\u00f4le entrant d'un autre b\u00e2timent ou d'une autre zone de mise \u00e0 la terre.<\/li>\r\n      <\/ul>\r\n    <\/div>\r\n\r\n    <div class=\"leeyee-mini-card\">\r\n      <span class=\"leeyee-small-label\">Risque inf\u00e9rieur<\/span>\r\n      <h3>Peut ne pas toujours n\u00e9cessiter de SPD s\u00e9par\u00e9<\/h3>\r\n      <ul>\r\n        <li>C\u00e2blage interne tr\u00e8s court \u00e0 l'int\u00e9rieur de la m\u00eame armoire.<\/li>\r\n        <li>Module PLC et I\/O install\u00e9 dans un seul bo\u00eetier prot\u00e9g\u00e9.<\/li>\r\n        <li>Pas de c\u00e2ble ext\u00e9rieur et pas de long trajet de c\u00e2ble de terrain.<\/li>\r\n        <li>Signal de contr\u00f4le non critique de faible valeur.<\/li>\r\n        <li>La sp\u00e9cification du projet ne n\u00e9cessite pas de protection contre les surtensions sur la ligne de signal.<\/li>\r\n      <\/ul>\r\n    <\/div>\r\n  <\/div>\r\n\r\n  <p>Pour les panneaux de contr\u00f4le OEM, l'approche la plus s\u00fbre est de confirmer cela pendant la conception plut\u00f4t que d'attendre la mise en service sur site. Une fois que le panneau a d\u00e9j\u00e0 \u00e9t\u00e9 c\u00e2bl\u00e9, l'ajout de SPDs de signal peut n\u00e9cessiter des modifications de la disposition des bornes, de l'espace sur le rail DIN, un examen de la mise \u00e0 la terre et de nouveaux dessins de c\u00e2blage.<\/p>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"do-you-need-surge-protection-on-every-plc-io-point\"><\/span>Avez-vous besoin d'une protection contre les surtensions sur chaque point E\/S PLC ?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>En g\u00e9n\u00e9ral, non. Installer un SPD sur chaque point d'E\/S peut augmenter les co\u00fbts, l'espace dans l'armoire, le temps de c\u00e2blage et la complexit\u00e9 de la maintenance.<\/p>\r\n\r\n  <p>Une meilleure m\u00e9thode de s\u00e9lection B2B consiste \u00e0 regrouper les points d'E\/S par exposition :<\/p>\r\n\r\n  <div class=\"leeyee-table-wrap\">\r\n    <table class=\"leeyee-table\">\r\n      <thead>\r\n        <tr>\r\n          <th>Groupe d'E\/S<\/th>\r\n          <th>Niveau de risque<\/th>\r\n          <th>Recommandation pratique<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td>Signaux internes de l'armoire<\/td>\r\n          <td>Faible<\/td>\r\n          <td>S'appuient g\u00e9n\u00e9ralement sur une bonne mise \u00e0 la terre de l'armoire, une s\u00e9paration des c\u00e2blages et une protection c\u00f4t\u00e9 alimentation.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Capteurs mont\u00e9s sur machine de courte port\u00e9e<\/td>\r\n          <td>Moyenne<\/td>\r\n          <td>Examiner le trajet du c\u00e2ble, l'environnement de la machine et la sp\u00e9cification du client.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Capteurs ext\u00e9rieurs ou c\u00e2bles de champ longs<\/td>\r\n          <td>Haut<\/td>\r\n          <td>Utilisez un SPD de signal pr\u00e8s de l'entr\u00e9e du c\u00e2ble du cabinet ou avant le terminal PLC.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>RS485 entre armoires ou b\u00e2timents<\/td>\r\n          <td>Haut<\/td>\r\n          <td>Utilisez un SPD de signal RS485 \/ donn\u00e9es appropri\u00e9 et confirmez la tension, le protocole, le d\u00e9bit et la mise \u00e0 la terre.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Mesure critique de processus<\/td>\r\n          <td>Haut<\/td>\r\n          <td>Prot\u00e9gez le signal de boucle analogique ou du transmetteur l\u00e0 o\u00f9 les temps d'arr\u00eat ou les fausses lectures sont co\u00fbteux.<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n  <\/div>\r\n\r\n  <div class=\"leeyee-note-box\">\r\n    <h3>R\u00e8gle simple pour les constructeurs de panneaux<\/h3>\r\n    <p>Si le c\u00e2ble reste \u00e0 l'int\u00e9rieur du cabinet, le risque de surtension est g\u00e9n\u00e9ralement plus faible. Si le c\u00e2ble sort du cabinet et va vers le terrain, consid\u00e9rez-le comme un chemin d'entr\u00e9e potentiel pour les surtensions.<\/p>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"signal-spd-vs-spd-remote-alarm-contact\"><\/span>SPD de signal vs contact d'alarme \u00e0 distance SPD<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>Ces deux termes sont souvent confondus, notamment dans les armoires PLC.<\/p>\r\n\r\n  <p>A <strong>surtension SPD<\/strong> prot\u00e8ge une ligne de communication ou de contr\u00f4le basse tension, telle que RS485, le c\u00e2blage des capteurs ou un circuit de signal industriel.<\/p>\r\n\r\n  <p>Un <strong>Contact d'alarme distant SPD<\/strong> n'est qu'un contact d'\u00e9tat sur un SPD de puissance. Il indique au PLC si le module SPD est normal ou d\u00e9faillant. Il ne prot\u00e8ge pas la ligne de signal du PLC elle-m\u00eame.<\/p>\r\n\r\n  <div class=\"leeyee-table-wrap\">\r\n    <table class=\"leeyee-table\">\r\n      <thead>\r\n        <tr>\r\n          <th>Article<\/th>\r\n          <th>SPD de Signal<\/th>\r\n          <th>Contact d'alarme distant SPD<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td>Fonction principale<\/td>\r\n          <td>Limite la tension de surtension sur une ligne de signal ou de communication.<\/td>\r\n          <td>Envoie l'\u00e9tat du SPD au PLC, BMS, SCADA, lampe ou circuit d'alarme.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Bornes typiques<\/td>\r\n          <td>Bornes de signal d'entr\u00e9e \/ sortie, borne PE ou de terre.<\/td>\r\n          <td>Bornes de contact sec NO \/ NC \/ COM.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Utilis\u00e9 pour<\/td>\r\n          <td>RS485, ligne de capteur, 4-20mA, t\u00e9l\u00e9m\u00e9trie, signal de t\u00e9l\u00e9commande.<\/td>\r\n          <td>Surveillance de la d\u00e9faillance \u00e9ventuelle d\u2019une cartouche SPD CA ou CC.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Peut-il prot\u00e9ger les E\/S du PLC ?<\/td>\r\n          <td>Oui, lorsqu\u2019il est correctement s\u00e9lectionn\u00e9 et install\u00e9 dans la ligne de signal.<\/td>\r\n          <td>Non. Il indique uniquement l\u2019\u00e9tat du SPD.<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n  <\/div>\r\n\r\n  <p>Pour les d\u00e9tails du c\u00e2blage de l\u2019alarme \u00e0 distance, consultez notre guide : <a href=\"https:\/\/www.cnspd.com\/fr\/spd-remote-alarm-plc\/\">C\u00e2blage du contact d\u2019alarme \u00e0 distance du SPD vers le PLC<\/a>.<\/p>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"signal-spd-selection-for-plc-dido-aiao-rs485-and-4-20ma-lines\"><\/span>S\u00e9lection de SPD de signal pour lignes PLC DI\/DO, AI\/AO, RS485 et 4-20mA<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>Le SPD de signal appropri\u00e9 est s\u00e9lectionn\u00e9 en fonction du circuit de signal r\u00e9el, et non de la taille de l\u2019armoire ni de la tension du syst\u00e8me CA.<\/p>\r\n\r\n  <div class=\"leeyee-steps\">\r\n    <div class=\"leeyee-step\">\r\n      <h3>Confirmer le type de signal<\/h3>\r\n      <p>V\u00e9rifiez si la ligne est DI\/DO, AI\/AO, RS485, 4-20mA, signal de capteur, t\u00e9l\u00e9m\u00e9trie, t\u00e9l\u00e9commande ou une autre ligne de communication basse tension.<\/p>\r\n    <\/div>\r\n\r\n    <div class=\"leeyee-step\">\r\n      <h3>Faire correspondre la tension de fonctionnement<\/h3>\r\n      <p>La tension SPD s\u00e9lectionn\u00e9e doit \u00eatre adapt\u00e9e \u00e0 la tension nominale du signal. Une ligne de signal de 5V, 12V, 24V ou 48V ne doit pas \u00eatre trait\u00e9e comme un circuit d\u2019alimentation CA.<\/p>\r\n    <\/div>\r\n\r\n    <div class=\"leeyee-step\">\r\n      <h3>V\u00e9rifier le courant de charge<\/h3>\r\n      <p>Le SPD de signal doit supporter le courant nominal de la boucle ou du circuit de signal. C\u2019est particuli\u00e8rement important pour les boucles analogiques et les dispositifs de terrain aliment\u00e9s.<\/p>\r\n    <\/div>\r\n\r\n    <div class=\"leeyee-step\">\r\n      <h3>V\u00e9rifier les exigences de transmission<\/h3>\r\n      <p>Pour les lignes RS485, de donn\u00e9es, de t\u00e9l\u00e9m\u00e9trie ou de communication, confirmez le d\u00e9bit en bauds, la distance de transmission, le type de c\u00e2ble et si le SPD peut affecter la qualit\u00e9 du signal.<\/p>\r\n    <\/div>\r\n\r\n    <div class=\"leeyee-step\">\r\n      <h3>Confirmer le nombre de fils et la disposition des bornes<\/h3>\r\n      <p>V\u00e9rifiez si la ligne prot\u00e9g\u00e9e est un c\u00e2ble \u00e0 2 fils, 3 fils, 4 fils, \u00e0 paire blind\u00e9e ou multiconducteur. La disposition des bornes du SPD doit correspondre \u00e0 la m\u00e9thode de c\u00e2blage.<\/p>\r\n    <\/div>\r\n\r\n    <div class=\"leeyee-step\">\r\n      <h3>Planifier la mise \u00e0 la terre et la position d\u2019installation<\/h3>\r\n      <p>Installez le SPD de signal \u00e0 proximit\u00e9 du point d\u2019entr\u00e9e du c\u00e2ble de terrain dans l\u2019armoire. Gardez la connexion de mise \u00e0 la terre courte et directe. \u00c9vitez d\u2019acheminer le c\u00e2ble de terrain non prot\u00e9g\u00e9 profond\u00e9ment dans la zone de c\u00e2blage propre du PLC.<\/p>\r\n    <\/div>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"recommended-selection-by-plc-signal-type\"><\/span>S\u00e9lection recommand\u00e9e par type de signal PLC<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <div class=\"leeyee-table-wrap\">\r\n    <table class=\"leeyee-table\">\r\n      <thead>\r\n        <tr>\r\n          <th>Application<\/th>\r\n          <th>Ce qu'il faut confirmer<\/th>\r\n          <th>Orientation du choix du SPD<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td>Entr\u00e9e num\u00e9rique 24V<\/td>\r\n          <td>Type d\u2019entr\u00e9e, longueur du c\u00e2ble, tension de terrain, r\u00e9f\u00e9rence commune, disposition des bornes<\/td>\r\n          <td>Utilisez un SPD de signal con\u00e7u pour le signal de commande 24V et adapt\u00e9 au c\u00e2blage de terrain.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Sortie num\u00e9rique \/ signal de relais<\/td>\r\n          <td>Type de charge, fr\u00e9quence de commutation, charge inductive, courant, trajet de c\u00e2blage<\/td>\r\n          <td>Confirmez si une protection contre les surtensions est n\u00e9cessaire pr\u00e8s de la charge, \u00e0 l\u2019entr\u00e9e de l\u2019armoire, ou aux deux endroits.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Boucle analogique 4-20mA<\/td>\r\n          <td>Tension de boucle, courant, emplacement du transmetteur, source d\u2019alimentation de la boucle, m\u00e9thode de mise \u00e0 la terre<\/td>\r\n          <td>S\u00e9lectionnez un SPD de signal qui ne perturbe pas la mesure analogique et prend en charge la tension de boucle.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Signal analogique 0-10V<\/td>\r\n          <td>Tension du signal, imp\u00e9dance d\u2019entr\u00e9e, trajet du c\u00e2ble, exposition au bruit<\/td>\r\n          <td>Utilisez une protection de signal basse tension adapt\u00e9e aux entr\u00e9es analogiques sensibles.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>RS485 \/ Modbus RTU<\/td>\r\n          <td>Version tension, d\u00e9bit en bauds, longueur du c\u00e2ble, mise \u00e0 la terre du blindage, nombre de n\u0153uds<\/td>\r\n          <td>Utilisez un SPD RS485 \/ signal de donn\u00e9es avec des performances de transmission adapt\u00e9es et une faible perte d\u2019insertion.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Capteur \/ instrument de terrain<\/td>\r\n          <td>Tension du capteur, nombre de fils, type de sortie, exposition ext\u00e9rieure, trajet du chemin de c\u00e2bles<\/td>\r\n          <td>Choisissez en fonction de la tension du capteur et de la m\u00e9thode de c\u00e2blage. Installez-le avant l\u2019API ou le module de signal.<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"plc-signal-spd-parameter-matrix\"><\/span>Matrice des param\u00e8tres SPD de signal PLC<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>Cette matrice aide les acheteurs \u00e0 traduire le type de signal de l\u2019API en d\u00e9tails pratiques pour la s\u00e9lection d\u2019un SPD. Elle ne remplace pas une fiche technique, mais elle permet d\u2019\u00e9viter l\u2019erreur la plus courante : choisir un SPD de signal uniquement sur son apparence ou son calibre en kA.<\/p>\r\n\r\n  <div class=\"leeyee-table-wrap\">\r\n    <table class=\"leeyee-table\">\r\n      <thead>\r\n        <tr>\r\n          <th>Ligne de signal<\/th>\r\n          <th>Tension courante<\/th>\r\n          <th>Crit\u00e8res de s\u00e9lection du SPD<\/th>\r\n          <th>LEEYEE LY10 Direction<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td>RS485 \/ Modbus RTU<\/td>\r\n          <td>D\u00e9pend du syst\u00e8me, souvent un circuit de communication basse tension<\/td>\r\n          <td>Transmission rate, insertion loss, terminal layout, grounding and shield treatment<\/td>\r\n          <td>Confirm 12V \/ 24V \/ 48V version according to the actual communication circuit.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>24V DI \/ DO<\/td>\r\n          <td>24V DC control signal<\/td>\r\n          <td>Uc \/ MCOV above normal control voltage, load current, wiring route, grounding<\/td>\r\n          <td>24V version with 30V DC MCOV may be considered when the circuit matches the product parameters.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Boucle analogique 4-20mA<\/td>\r\n          <td>Usually powered by a 24V loop supply<\/td>\r\n          <td>Loop voltage, loop current, measurement accuracy, low signal disturbance<\/td>\r\n          <td>Confirm loop voltage and current first. Do not select only by the PLC input module name.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Ligne de capteur<\/td>\r\n          <td>12V \/ 24V \/ 48V depending on sensor type<\/td>\r\n          <td>Sensor voltage, wire count, output type, cable route, outdoor exposure<\/td>\r\n          <td>Match 12V \/ 24V \/ 48V version to the real sensor circuit.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Telemetry \/ Remote Control<\/td>\r\n          <td>12V \/ 24V \/ 48V or project-specific<\/td>\r\n          <td>Protocol, cable length, surge exposure, grounding zone, terminal arrangement<\/td>\r\n          <td>Match voltage and protocol requirement before confirming model.<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n  <\/div>\r\n\r\n  <div class=\"leeyee-warning-box\">\r\n    <h3>Professional Boundary<\/h3>\r\n    <p>LY10 is mainly suitable for RS485, telemetry, remote-control, sensor, and low-voltage industrial signal lines when the circuit parameters match the product rating.<\/p>\r\n    <p>For Ethernet, PoE, Profibus, special high-speed communication interfaces, or project-specific bus systems, confirm the interface type and use a matched data-line SPD instead of assuming one model fits all signal lines.<\/p>\r\n  <\/div>\r\n\r\n  <div class=\"leeyee-product-box\">\r\n    <h2><span class=\"ez-toc-section\" id=\"recommended-leeyee-signal-spd-for-plc-and-rs485-lines\"><\/span>SPD de signal LEEYEE recommand\u00e9 pour les lignes PLC et RS485<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n    <p>For RS485, telemetry, remote-control, PLC, sensor, and industrial communication lines, LEEYEE LY10 is a DIN-rail data signal surge protector designed for control cabinets and industrial signal circuits.<\/p>\r\n    <p>Typical available versions include 12V, 24V, and 48V signal systems. The product is designed for DIN-rail installation and series connection before sensitive equipment.<\/p>\r\n\r\n    <div class=\"leeyee-table-wrap\">\r\n      <table class=\"leeyee-table\">\r\n        <thead>\r\n          <tr>\r\n            <th>Param\u00e8tres<\/th>\r\n            <th>LY10 Selection Data<\/th>\r\n          <\/tr>\r\n        <\/thead>\r\n        <tbody>\r\n          <tr>\r\n            <td>Product type<\/td>\r\n            <td>RS485 \/ data signal surge protector<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td>Tension nominale de fonctionnement<\/td>\r\n            <td>12V \/ 24V \/ 48V DC<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td>Tension de fonctionnement maximale continue<\/td>\r\n            <td>15V \/ 30V \/ 60V DC<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td>Courant de charge nominal<\/td>\r\n            <td>500mA<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td>Taux de transmission<\/td>\r\n            <td>Jusqu'\u00e0 10Mbps<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td>Perte d'insertion<\/td>\r\n            <td>\u2264 0.2dB<\/td>\r\n          <\/tr>\r\n          <tr>\r\n            <td>Installation<\/td>\r\n            <td>35mm DIN rail \/ terminal connection<\/td>\r\n          <\/tr>\r\n        <\/tbody>\r\n      <\/table>\r\n    <\/div>\r\n\r\n    <div class=\"leeyee-button-row\">\r\n      <a class=\"leeyee-article-btn\" href=\"https:\/\/www.cnspd.com\/fr\/ly10-data-signaldc-surge-protective-device-2-product\/\">\r\n        <span>Voir le SPD de signal LY10<\/span>\r\n      <\/a>\r\n      <button type=\"button\" class=\"leeyee-site-popup-btn leeyee-inquiry-btn\" aria-label=\"Demander une recommandation de mod\u00e8le\">\r\n        <span class=\"w-btn-label\">Demander une recommandation de mod\u00e8le<\/span>\r\n      <\/button>\r\n    <\/div>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"where-should-the-signal-spd-be-installed\"><\/span>O\u00f9 le SPD de signal doit-il \u00eatre install\u00e9 ?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>For PLC control panels, the best practical location is usually near the field cable entry point, before the cable reaches the PLC terminal or communication module.<\/p>\r\n\r\n  <p>This helps stop the surge before it travels through the clean control wiring area inside the cabinet.<\/p>\r\n\r\n  <figure class=\"leeyee-article-figure\">\r\n    <img src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/signal-spd-installation-position-for-plc-io-lines-scaled.webp\" alt=\"Signal SPD installation position for PLC I O lines at field cable entry inside an industrial control panel\" loading=\"lazy\" decoding=\"async\">\r\n    <figcaption>Install the signal SPD near the field cable entry point, with a short PE connection, before the protected wiring reaches the PLC I\/O module.<\/figcaption>\r\n  <\/figure>\r\n\r\n  <div class=\"leeyee-table-wrap\">\r\n    <table class=\"leeyee-table\">\r\n      <thead>\r\n        <tr>\r\n          <th>Position d'installation<\/th>\r\n          <th>Recommended?<\/th>\r\n          <th>Raison<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td>At field cable entry terminal row<\/td>\r\n          <td>Best practice<\/td>\r\n          <td>Intercepts surge before it enters the PLC wiring area.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Directly beside PLC module<\/td>\r\n          <td>Sometimes acceptable<\/td>\r\n          <td>Better than no protection, but unprotected cable may still run inside the cabinet.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Only at main AC panel<\/td>\r\n          <td>Not enough for signal lines<\/td>\r\n          <td>AC SPD does not clamp the low-voltage signal cable entering PLC terminals.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Only at remote field device<\/td>\r\n          <td>Depends on layout<\/td>\r\n          <td>May protect the field device, but the PLC side may still need protection if the cable is long or exposed.<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n  <\/div>\r\n\r\n  <div class=\"leeyee-warning-box\">\r\n    <h3>Erreur courante<\/h3>\r\n    <p>Do not install the signal SPD far away from the protected equipment and then run long unprotected signal wiring inside the control cabinet. The cable between the entry point and the PLC can still carry surge energy and noise into the sensitive area.<\/p>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"what-happens-if-plc-signal-lines-are-not-protected\"><\/span>Que se passe-t-il si les lignes de signal PLC ne sont pas prot\u00e9g\u00e9es ?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>The failure may not always look like a burned component. In many industrial sites, surge-related signal problems first appear as unstable communication, random input alarms, analog measurement drift, or repeated failure of the same I\/O channel.<\/p>\r\n\r\n  <p>Les r\u00e9sultats possibles incluent :<\/p>\r\n\r\n  <ul>\r\n    <li>PLC communication port damage.<\/li>\r\n    <li>RS485 or Modbus RTU communication loss.<\/li>\r\n    <li>Analog input reading instability.<\/li>\r\n    <li>False alarm from field sensors.<\/li>\r\n    <li>Repeated I\/O module replacement.<\/li>\r\n    <li>Unexpected machine stop or production downtime.<\/li>\r\n    <li>Hard-to-diagnose intermittent faults after storms or switching events.<\/li>\r\n  <\/ul>\r\n\r\n  <p>For factory maintenance teams, these failures are expensive because the damaged PLC module is only part of the cost. The bigger cost is troubleshooting time, line stoppage, emergency replacement, and repeated site visits.<\/p>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"before-ordering-signal-spd-for-plc-panels\"><\/span>Avant de commander un SPD de signal pour les panneaux PLC<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <figure class=\"leeyee-article-figure\">\r\n    <img src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/plc-signal-spd-selection-checklist-scaled.webp\" alt=\"PLC signal SPD selection checklist for DI DO AI AO RS485 4-20mA sensor and field device lines\" loading=\"lazy\" decoding=\"async\">\r\n    <figcaption>Before ordering signal SPD for PLC panels, confirm the signal type, voltage, current, communication requirement, wiring method, and installation condition.<\/figcaption>\r\n  <\/figure>\r\n\r\n  <div class=\"leeyee-check-box\">\r\n    <h3>Send These Details for Faster Model Selection<\/h3>\r\n    <ul>\r\n      <li>Signal type: DI, DO, AI, AO, RS485, 4-20mA, sensor, telemetry, or other.<\/li>\r\n      <li>Normal operating voltage: 5V, 12V, 24V, 48V, or other.<\/li>\r\n      <li>Maximum continuous voltage required by the project.<\/li>\r\n      <li>Load current or loop current.<\/li>\r\n      <li>Protocol and baud rate for communication lines.<\/li>\r\n      <li>Number of wires and terminal arrangement.<\/li>\r\n      <li>Cable route: indoor, outdoor, between cabinets, between buildings, or near power cables.<\/li>\r\n      <li>Grounding method and shield grounding requirement.<\/li>\r\n      <li>Installation space: DIN rail width, terminal layout, cabinet depth.<\/li>\r\n      <li>OEM label, private label, datasheet, packaging, or wiring diagram requirements.<\/li>\r\n    <\/ul>\r\n\r\n    <div class=\"leeyee-button-row\">\r\n      <button type=\"button\" class=\"leeyee-site-popup-btn leeyee-inquiry-btn\" aria-label=\"Send Your PLC Signal Requirement\">\r\n        <span class=\"w-btn-label\">Send Your PLC Signal Requirement<\/span>\r\n      <\/button>\r\n      <a class=\"leeyee-article-btn secondary\" href=\"https:\/\/www.cnspd.com\/fr\/protection-contre-les-surtensions-pour-les-panneaux-de-controle-industriels\/\">\r\n        <span>View Control Panel SPD Guide<\/span>\r\n      <\/a>\r\n    <\/div>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"common-selection-mistakes\"><\/span>Erreurs courantes de s\u00e9lection<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <div class=\"leeyee-table-wrap\">\r\n    <table class=\"leeyee-table\">\r\n      <thead>\r\n        <tr>\r\n          <th>Erreur<\/th>\r\n          <th>Pourquoi c\u2019est un probl\u00e8me<\/th>\r\n          <th>Meilleure pratique<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td>Using an AC SPD on RS485 or signal line<\/td>\r\n          <td>AC SPD voltage level and test standard are not suitable for low-voltage data lines.<\/td>\r\n          <td>Use a signal\/data SPD matched to the communication or control circuit.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Choosing only by kA rating<\/td>\r\n          <td>Signal SPD selection also depends on voltage, current, transmission rate, and wiring method.<\/td>\r\n          <td>Confirm the actual signal circuit before selecting the SPD.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Ignoring insertion loss or data rate<\/td>\r\n          <td>Wrong SPD may affect communication quality on RS485 or data lines.<\/td>\r\n          <td>Check transmission rate, insertion loss, baud rate, and cable length.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Installing SPD without good grounding<\/td>\r\n          <td>Poor grounding limits the surge discharge path and reduces protection effect.<\/td>\r\n          <td>Keep grounding short, direct, and consistent with cabinet grounding design.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Confusing remote alarm contact with signal SPD<\/td>\r\n          <td>Remote contact only reports SPD status. It does not protect signal wiring.<\/td>\r\n          <td>Use remote alarm for monitoring and signal SPD for signal-line protection.<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td>Protecting only one side of a long outdoor line<\/td>\r\n          <td>Long cable routes may expose both equipment ends to surge risk.<\/td>\r\n          <td>Review whether both PLC side and field device side need coordinated protection.<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"related-reading\"><\/span>Lectures connexes<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>If you are designing a complete industrial control panel, these pages can help you separate power-side protection, signal-side protection, and monitoring requirements.<\/p>\r\n\r\n  <ul class=\"leeyee-related-list\">\r\n    <li><a href=\"https:\/\/www.cnspd.com\/fr\/protection-contre-les-surtensions-pour-les-panneaux-de-controle-industriels\/\">Protection contre les surtensions pour les panneaux de contr\u00f4le industriels<\/a> \u2014 for complete AC, DC, PLC, VFD, and control cabinet protection logic.<\/li>\r\n    <li><a href=\"https:\/\/www.cnspd.com\/fr\/rs485-spd-guide\/\">Guide de c\u00e2blage et de s\u00e9lection des SPD RS485<\/a> \u2014 for RS485 \/ Modbus RTU signal line protection.<\/li>\r\n    <li><a href=\"https:\/\/www.cnspd.com\/fr\/spd-remote-alarm-plc\/\">C\u00e2blage du contact d\u2019alarme \u00e0 distance du SPD vers le PLC<\/a> \u2014 for NO \/ NC \/ COM dry contact monitoring.<\/li>\r\n    <li><a href=\"https:\/\/www.cnspd.com\/fr\/ly10-data-signaldc-surge-protective-device-2-product\/\">LY10 RS485 DIN-Rail Data Signal Surge Protector<\/a> \u2014 for RS485, PLC, telemetry, sensor, and industrial signal lines.<\/li>\r\n  <\/ul>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"faq-plc-io-signal-surge-protection\"><\/span>FAQ : Protection contre les surtensions des signaux E\/S PLC<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <div class=\"leeyee-faq\">\r\n    <details>\r\n      <summary>Do PLC signal lines need surge protection?<\/summary>\r\n      <p>PLC signal lines need surge protection when they connect to outdoor sensors, long field cables, remote I\/O, RS485 networks, field instruments, or devices installed in another cabinet or grounding zone. Short internal cabinet wiring may not always need a separate signal SPD.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>What is the difference between PLC I\/O surge protection and AC panel surge protection?<\/summary>\r\n      <p>AC panel surge protection protects the incoming power side of the control cabinet. PLC I\/O surge protection protects low-voltage signal paths such as digital input, analog input, RS485, 4-20mA, sensor, and field device wiring. These two protection points serve different circuits.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Can an AC Type 2 SPD protect PLC I\/O terminals?<\/summary>\r\n      <p>An AC Type 2 SPD protects the power input of the control cabinet. It does not directly protect low-voltage signal wiring connected to PLC I\/O or communication terminals. Signal lines need suitable signal SPDs when they are exposed to surge risk.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Should every PLC input and output have a surge protector?<\/summary>\r\n      <p>Not always. A practical design protects the high-risk lines first: outdoor sensors, long field cables, RS485 bus lines, remote I\/O, analog loops, and cables running near motors or VFDs. Internal short wiring inside the same cabinet may not need one SPD per point.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Can I use one signal SPD for multiple PLC I\/O lines?<\/summary>\r\n      <p>Only when the SPD design, terminal arrangement, voltage rating, current capacity, and wiring method are suitable for those lines. Do not combine unrelated signal types blindly. RS485, analog loop, digital input, and sensor lines may need different protection arrangements.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>What voltage signal SPD should I choose for a 24V PLC input?<\/summary>\r\n      <p>Choose a signal SPD whose rated voltage and maximum continuous operating voltage are suitable for the normal 24V DC control signal. For example, a 24V signal SPD with a suitable MCOV above the normal working voltage may be considered, but the final choice should also check current, wiring method, grounding, and project requirements.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>What SPD should be used for RS485 connected to a PLC?<\/summary>\r\n      <p>Use a data or signal SPD designed for RS485 and similar industrial communication circuits. Confirm voltage version, baud rate, transmission distance, insertion loss, number of wires, shield grounding, and installation position before ordering.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Can a signal SPD be used for 4-20mA analog loops?<\/summary>\r\n      <p>Yes, if the SPD is suitable for the loop voltage, loop current, wiring method, and measurement accuracy requirement. The SPD should protect the analog signal without disturbing normal 4-20mA operation.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Where should a signal SPD be installed in a PLC cabinet?<\/summary>\r\n      <p>Install it close to the field cable entry point or terminal row before the signal wire reaches the PLC module. Keep the grounding connection short and direct, and avoid long unprotected signal wiring inside the clean control area.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Is an SPD remote alarm contact the same as signal surge protection?<\/summary>\r\n      <p>No. A remote alarm contact is a dry contact used to report SPD status to a PLC, BMS, SCADA, lamp, or alarm circuit. A signal SPD is installed in the signal line to limit surge voltage before it reaches sensitive equipment.<\/p>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>What information should I send to choose a PLC signal SPD?<\/summary>\r\n      <p>Send the signal type, operating voltage, line current, protocol, baud rate, number of wires, cable route, grounding method, cabinet installation space, and any OEM label or wiring diagram requirement. This helps the supplier recommend a suitable signal SPD model faster.<\/p>\r\n    <\/details>\r\n  <\/div>\r\n\r\n  <section class=\"leeyee-cta-box\">\r\n    <h2><span class=\"ez-toc-section\" id=\"need-help-choosing-signal-spd-for-a-plc-control-panel\"><\/span>Besoin d'aide pour choisir un SPD de signal pour un panneau de contr\u00f4le PLC ?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n    <p>Send us your PLC signal type, voltage, cable route, and cabinet layout. LEEYEE can help recommend a suitable signal SPD for RS485, sensor, telemetry, remote-control, and industrial communication lines.<\/p>\r\n    <div class=\"leeyee-button-row\">\r\n      <button type=\"button\" class=\"leeyee-site-popup-btn leeyee-inquiry-btn\" aria-label=\"Request Signal SPD Selection\">\r\n        <span class=\"w-btn-label\">Request Signal SPD Selection<\/span>\r\n      <\/button>\r\n      <a class=\"leeyee-article-btn secondary\" href=\"https:\/\/www.cnspd.com\/fr\/ly10-data-signaldc-surge-protective-device-2-product\/\">\r\n        <span>View LY10 Product Page<\/span>\r\n      <\/a>\r\n    <\/div>\r\n  <\/section>\r\n\r\n<\/article>\r\n\r\n<script>\r\n  document.addEventListener('DOMContentLoaded', function () {\r\n    var popupButtons = document.querySelectorAll('.leeyee-site-popup-btn');\r\n\r\n    popupButtons.forEach(function (button) {\r\n      button.addEventListener('click', function () {\r\n        var realPopupTrigger = document.querySelector('.w-popup.ush_popup_1 .w-popup-trigger');\r\n\r\n        if (realPopupTrigger) {\r\n          realPopupTrigger.click();\r\n        } else {\r\n          window.open('https:\/\/www.cnspd.com\/contact\/', '_blank', 'noopener');\r\n        }\r\n      });\r\n    });\r\n  });\r\n<\/script>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"<p>Technical guide for PLC control panels A PLC cabinet may already have an AC surge protective device at the power input, but that does not automatically protect the PLC signal terminals. Many PLC failures come through the \u201csmall\u201d lines: digital input, digital output, analog input, analog output, RS485, 4-20mA loop, sensor cable, remote I\/O cable,&#8230;<\/p>","protected":false},"author":18,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,488,422],"tags":[],"class_list":["post-29895","post","type-post","status-publish","format-standard","hentry","category-news","category-surge-protection","category-industry-news"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.1 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>PLC I\/O Signal Surge Protection Guide | Signal SPD for Control Panels<\/title>\n<meta name=\"description\" content=\"Learn when PLC DI\/DO, AI\/AO, RS485, 4-20mA, sensor and field device lines need signal surge protection, and how to choose the right DIN rail signal SPD for industrial control panels.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/\" \/>\n<meta property=\"og:locale\" content=\"fr_FR\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"PLC I\/O Signal Surge Protection Guide | Signal SPD for Control Panels\" \/>\n<meta property=\"og:description\" content=\"Learn when PLC DI\/DO, AI\/AO, RS485, 4-20mA, sensor and field device lines need signal surge protection, and how to choose the right DIN rail signal SPD for industrial control panels.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.cnspd.com\/fr\/plc-io-signal-surge-protection\/\" \/>\n<meta property=\"og:site_name\" content=\"Surge Protector, Surge Arrestor, Isolating Switch - 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