{"id":30565,"date":"2026-07-29T12:39:05","date_gmt":"2026-07-29T04:39:05","guid":{"rendered":"https:\/\/www.cnspd.com\/?p=30565"},"modified":"2026-07-30T15:09:18","modified_gmt":"2026-07-30T07:09:18","slug":"access-control-surge-protection-guide-for-power-readers-locks-and-poe","status":"publish","type":"post","link":"https:\/\/www.cnspd.com\/es\/access-control-surge-protection\/","title":{"rendered":"Access Control Surge Protection Guide for Power, Readers, Locks and PoE"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"30565\" class=\"elementor elementor-30565\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-ac2fc7d e-flex e-con-boxed e-con e-parent\" data-id=\"ac2fc7d\" 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-fccfba0 elementor-widget elementor-widget-html\" data-id=\"fccfba0\" 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-access-control-guide {\r\n  --ac-blue: #004898;\r\n  --ac-blue-dark: #00366f;\r\n  --ac-blue-soft: #eef5ff;\r\n  --ac-bg-soft: #f7fbff;\r\n  --ac-text: #26333f;\r\n  --ac-heading: #172530;\r\n  --ac-muted: #5d6a76;\r\n  --ac-border: #d6e0e9;\r\n  --ac-warning: #824208;\r\n  --ac-warning-bg: #fff8ef;\r\n  width: 100%;\r\n  max-width: 840px;\r\n  margin: 0 auto;\r\n  padding: 18px 22px 72px;\r\n  color: var(--ac-text);\r\n  font-size: 17px;\r\n  line-height: 1.72;\r\n  overflow-wrap: break-word;\r\n}\r\n\r\n#leeyee-access-control-guide,\r\n#leeyee-access-control-guide *,\r\n#leeyee-access-control-guide *::before,\r\n#leeyee-access-control-guide *::after {\r\n  box-sizing: border-box;\r\n}\r\n\r\n#leeyee-access-control-guide p {\r\n  margin: 0 0 18px;\r\n}\r\n\r\n#leeyee-access-control-guide strong {\r\n  color: var(--ac-heading);\r\n}\r\n\r\n#leeyee-access-control-guide a {\r\n  color: var(--ac-blue);\r\n  text-decoration: underline;\r\n  text-decoration-thickness: 1px;\r\n  text-underline-offset: 3px;\r\n}\r\n\r\n#leeyee-access-control-guide h2 {\r\n  margin: 54px 0 18px;\r\n  color: var(--ac-heading);\r\n  font-size: clamp(27px, 4vw, 33px);\r\n  line-height: 1.24;\r\n  letter-spacing: -0.02em;\r\n}\r\n\r\n#leeyee-access-control-guide h3 {\r\n  margin: 34px 0 14px;\r\n  color: #1d2c38;\r\n  font-size: clamp(21px, 3vw, 25px);\r\n  line-height: 1.34;\r\n}\r\n\r\n#leeyee-access-control-guide h4 {\r\n  margin: 22px 0 10px;\r\n  color: #243540;\r\n  font-size: 18px;\r\n  line-height: 1.4;\r\n}\r\n\r\n#leeyee-access-control-guide ul,\r\n#leeyee-access-control-guide ol {\r\n  margin: 0 0 23px;\r\n  padding-left: 24px;\r\n}\r\n\r\n#leeyee-access-control-guide li {\r\n  margin-bottom: 9px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-intro {\r\n  margin-bottom: 20px;\r\n  color: #35434f;\r\n  font-size: 18px;\r\n  line-height: 1.72;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-ref {\r\n  margin-left: 2px;\r\n  font-size: 0.82em;\r\n  font-weight: 700;\r\n  text-decoration: none;\r\n  white-space: nowrap;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-quick-answer {\r\n  margin: 28px 0 35px;\r\n  padding: 25px 27px;\r\n  background: var(--ac-bg-soft);\r\n  border: 1px solid #cbddef;\r\n  border-left: 5px solid var(--ac-blue);\r\n  border-radius: 9px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-quick-answer h2 {\r\n  margin: 0 0 12px;\r\n  color: var(--ac-blue-dark);\r\n  font-size: 25px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-quick-answer p:last-child,\r\n#leeyee-access-control-guide .ac-quick-answer ul:last-child {\r\n  margin-bottom: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-quick-list {\r\n  margin-top: 15px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table-wrap {\r\n  margin: 24px 0 30px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table-note {\r\n  margin-bottom: 11px;\r\n  color: var(--ac-muted);\r\n  font-size: 15px;\r\n  line-height: 1.55;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table {\r\n  width: 100%;\r\n  border-collapse: separate;\r\n  border-spacing: 0;\r\n  overflow: hidden;\r\n  border: 1px solid var(--ac-border);\r\n  border-radius: 8px;\r\n  font-size: 15px;\r\n  line-height: 1.5;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table th,\r\n#leeyee-access-control-guide .ac-table td {\r\n  padding: 13px 14px;\r\n  text-align: left;\r\n  vertical-align: top;\r\n  border-right: 1px solid var(--ac-border);\r\n  border-bottom: 1px solid var(--ac-border);\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table th:last-child,\r\n#leeyee-access-control-guide .ac-table td:last-child {\r\n  border-right: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table tbody tr:last-child td {\r\n  border-bottom: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table thead th {\r\n  color: #fff;\r\n  background: var(--ac-blue);\r\n  font-weight: 700;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table tbody tr:nth-child(even) {\r\n  background: #f9fbfd;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-table-conclusion {\r\n  margin: 11px 0 0;\r\n  color: #34434f;\r\n  font-size: 15px;\r\n  font-weight: 650;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-figure {\r\n  margin: 31px 0 39px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-figure img {\r\n  display: block;\r\n  width: 100%;\r\n  height: auto;\r\n  margin: 0;\r\n  border: 1px solid var(--ac-border);\r\n  border-radius: 8px;\r\n  background: #fff;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-figure figcaption {\r\n  margin-top: 11px;\r\n  color: var(--ac-muted);\r\n  font-size: 14px;\r\n  line-height: 1.55;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-callout {\r\n  margin: 25px 0;\r\n  padding: 21px 23px;\r\n  background: var(--ac-blue-soft);\r\n  border: 1px solid #c9ddf3;\r\n  border-radius: 8px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-callout h3 {\r\n  margin: 0 0 10px;\r\n  color: var(--ac-blue-dark);\r\n  font-size: 21px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-callout p:last-child,\r\n#leeyee-access-control-guide .ac-callout ul:last-child {\r\n  margin-bottom: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-warning {\r\n  margin: 25px 0;\r\n  padding: 21px 23px;\r\n  color: #60380f;\r\n  background: var(--ac-warning-bg);\r\n  border: 1px solid #edcfaa;\r\n  border-left: 5px solid var(--ac-warning);\r\n  border-radius: 8px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-warning h3 {\r\n  margin: 0 0 10px;\r\n  color: #713d0d;\r\n  font-size: 21px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-warning p:last-child,\r\n#leeyee-access-control-guide .ac-warning ul:last-child {\r\n  margin-bottom: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-meaning {\r\n  margin: 18px 0 24px;\r\n  padding-left: 16px;\r\n  color: #42515d;\r\n  font-size: 15px;\r\n  border-left: 3px solid #8cb2d8;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-meaning strong {\r\n  color: var(--ac-blue-dark);\r\n}\r\n\r\n#leeyee-access-control-guide .ac-risk-list {\r\n  margin: 21px 0 29px;\r\n  padding: 0;\r\n  list-style: none;\r\n  border-top: 1px solid var(--ac-border);\r\n}\r\n\r\n#leeyee-access-control-guide .ac-risk-list li {\r\n  position: relative;\r\n  margin: 0;\r\n  padding: 14px 0 14px 27px;\r\n  border-bottom: 1px solid var(--ac-border);\r\n}\r\n\r\n#leeyee-access-control-guide .ac-risk-list li::before {\r\n  content: \"\";\r\n  position: absolute;\r\n  top: 22px;\r\n  left: 3px;\r\n  width: 9px;\r\n  height: 9px;\r\n  background: var(--ac-blue);\r\n  border-radius: 50%;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-steps {\r\n  margin: 25px 0 30px;\r\n  padding: 0;\r\n  list-style: none;\r\n  counter-reset: ac-step;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-steps li {\r\n  position: relative;\r\n  margin: 0 0 15px;\r\n  padding: 18px 20px 18px 62px;\r\n  background: #fff;\r\n  border: 1px solid var(--ac-border);\r\n  border-radius: 8px;\r\n  counter-increment: ac-step;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-steps li::before {\r\n  content: counter(ac-step);\r\n  position: absolute;\r\n  top: 17px;\r\n  left: 18px;\r\n  display: grid;\r\n  width: 30px;\r\n  height: 30px;\r\n  place-items: center;\r\n  color: #fff;\r\n  background: var(--ac-blue);\r\n  border-radius: 50%;\r\n  font-size: 14px;\r\n  font-weight: 700;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-scenario {\r\n  margin: 19px 0;\r\n  padding: 18px 21px;\r\n  background: #fafcfe;\r\n  border-left: 4px solid #7d9fc1;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-scenario h3 {\r\n  margin: 0 0 8px;\r\n  font-size: 20px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-scenario p:last-child {\r\n  margin-bottom: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-checklist {\r\n  margin: 28px 0 33px;\r\n  padding: 25px;\r\n  background: var(--ac-bg-soft);\r\n  border: 1px solid #cbdeef;\r\n  border-radius: 9px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-checklist h2 {\r\n  margin-top: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-checklist-grid {\r\n  display: grid;\r\n  grid-template-columns: 1fr 1fr;\r\n  gap: 18px 28px;\r\n  margin-top: 23px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-checklist-group h3 {\r\n  margin: 0 0 9px;\r\n  color: var(--ac-blue-dark);\r\n  font-size: 18px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-checklist-group ul {\r\n  margin-bottom: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-review {\r\n  margin: 29px 0;\r\n  padding: 24px;\r\n  border: 1px solid var(--ac-border);\r\n  border-radius: 9px;\r\n  background: #fff;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-review h2 {\r\n  margin-top: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-review-grid {\r\n  display: grid;\r\n  grid-template-columns: 1fr 1fr;\r\n  gap: 15px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-review-item {\r\n  padding: 16px 17px;\r\n  background: var(--ac-bg-soft);\r\n  border-radius: 7px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-review-item h3 {\r\n  margin: 0 0 7px;\r\n  color: var(--ac-blue-dark);\r\n  font-size: 18px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-review-item p {\r\n  margin-bottom: 0;\r\n  font-size: 15px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-cta {\r\n  margin: 37px 0;\r\n  padding: 27px;\r\n  text-align: center;\r\n  background: var(--ac-blue-soft);\r\n  border: 1px solid #c7dcf2;\r\n  border-radius: 10px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-cta h2 {\r\n  margin: 0 0 11px;\r\n  color: var(--ac-blue-dark);\r\n  font-size: 26px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-cta p {\r\n  max-width: 680px;\r\n  margin: 0 auto 18px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-cta .leeyee-site-popup-btn {\r\n  display: inline-flex;\r\n  align-items: center;\r\n  justify-content: center;\r\n  min-width: 190px;\r\n  min-height: 48px;\r\n  margin: 0;\r\n  padding: 12px 24px;\r\n  border: 1px solid var(--ac-blue);\r\n  border-radius: 6px;\r\n  outline: none;\r\n  background: var(--ac-blue);\r\n  box-shadow: none;\r\n  cursor: pointer;\r\n  appearance: none;\r\n  -webkit-appearance: none;\r\n  font-family: inherit;\r\n  font-size: 16px;\r\n  font-weight: 700;\r\n  line-height: 1.3;\r\n  text-align: center;\r\n  text-decoration: none;\r\n  transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-cta .leeyee-site-popup-btn:hover {\r\n  border-color: var(--ac-blue-dark);\r\n  background: var(--ac-blue-dark);\r\n  transform: translateY(-1px);\r\n}\r\n\r\n#leeyee-access-control-guide .ac-cta .leeyee-site-popup-btn:focus-visible {\r\n  outline: 3px solid rgba(0, 72, 152, 0.22);\r\n  outline-offset: 3px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-cta .leeyee-site-popup-btn .w-btn-label {\r\n  display: block;\r\n  color: #fff;\r\n  font: inherit;\r\n  line-height: inherit;\r\n  white-space: normal;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-brand-note {\r\n  margin-top: 17px !important;\r\n  color: var(--ac-muted);\r\n  font-size: 14px;\r\n  line-height: 1.55;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-faq {\r\n  margin: 18px 0;\r\n  border-top: 1px solid var(--ac-border);\r\n}\r\n\r\n#leeyee-access-control-guide .ac-faq details {\r\n  border-bottom: 1px solid var(--ac-border);\r\n}\r\n\r\n#leeyee-access-control-guide .ac-faq summary {\r\n  position: relative;\r\n  padding: 18px 44px 18px 0;\r\n  color: #1d2b36;\r\n  font-weight: 700;\r\n  cursor: pointer;\r\n  list-style: none;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-faq summary::-webkit-details-marker {\r\n  display: none;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-faq summary::after {\r\n  content: \"+\";\r\n  position: absolute;\r\n  top: 13px;\r\n  right: 7px;\r\n  color: var(--ac-blue);\r\n  font-size: 26px;\r\n  font-weight: 400;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-faq details[open] summary::after {\r\n  content: \"\u2013\";\r\n}\r\n\r\n#leeyee-access-control-guide .ac-faq-answer {\r\n  padding: 0 0 18px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-faq-answer p:last-child {\r\n  margin-bottom: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-related {\r\n  margin: 34px 0;\r\n  padding: 22px 24px;\r\n  border: 1px solid var(--ac-border);\r\n  border-radius: 8px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-related h2 {\r\n  margin: 0 0 12px;\r\n  font-size: 24px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-related ul {\r\n  margin-bottom: 0;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-references {\r\n  margin-top: 52px;\r\n  padding-top: 24px;\r\n  color: #4e5c68;\r\n  font-size: 14px;\r\n  line-height: 1.65;\r\n  border-top: 2px solid var(--ac-border);\r\n}\r\n\r\n#leeyee-access-control-guide .ac-references h2 {\r\n  margin-top: 0;\r\n  font-size: 26px;\r\n}\r\n\r\n#leeyee-access-control-guide .ac-references li {\r\n  margin-bottom: 12px;\r\n}\r\n\r\n@media (max-width: 680px) {\r\n  #leeyee-access-control-guide {\r\n    padding: 14px 16px 58px;\r\n    font-size: 16px;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-intro {\r\n    font-size: 17px;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-quick-answer,\r\n  #leeyee-access-control-guide .ac-callout,\r\n  #leeyee-access-control-guide .ac-warning,\r\n  #leeyee-access-control-guide .ac-checklist,\r\n  #leeyee-access-control-guide .ac-review,\r\n  #leeyee-access-control-guide .ac-cta {\r\n    padding: 20px;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-checklist-grid,\r\n  #leeyee-access-control-guide .ac-review-grid {\r\n    grid-template-columns: 1fr;\r\n    gap: 15px;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-table,\r\n  #leeyee-access-control-guide .ac-table tbody,\r\n  #leeyee-access-control-guide .ac-table tr,\r\n  #leeyee-access-control-guide .ac-table td {\r\n    display: block;\r\n    width: 100%;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-table thead {\r\n    position: absolute;\r\n    width: 1px;\r\n    height: 1px;\r\n    overflow: hidden;\r\n    clip: rect(0 0 0 0);\r\n    white-space: nowrap;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-table {\r\n    border: 0;\r\n    border-radius: 0;\r\n    background: transparent;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-table tbody tr {\r\n    margin-bottom: 15px;\r\n    overflow: hidden;\r\n    background: #fff !important;\r\n    border: 1px solid var(--ac-border);\r\n    border-radius: 8px;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-table td {\r\n    display: grid;\r\n    grid-template-columns: minmax(108px, 39%) 1fr;\r\n    gap: 12px;\r\n    padding: 11px 13px;\r\n    border-right: 0;\r\n    border-bottom: 1px solid var(--ac-border);\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-table td:last-child {\r\n    border-bottom: 0;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-table td::before {\r\n    content: attr(data-label);\r\n    color: var(--ac-blue-dark);\r\n    font-weight: 700;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-steps li {\r\n    padding: 18px 17px 18px 56px;\r\n  }\r\n\r\n  #leeyee-access-control-guide .ac-cta .leeyee-site-popup-btn {\r\n    min-width: 0;\r\n    width: 100%;\r\n  }\r\n}\r\n\r\n@media (max-width: 390px) {\r\n  #leeyee-access-control-guide .ac-table td {\r\n    grid-template-columns: 1fr;\r\n    gap: 4px;\r\n  }\r\n}\r\n<\/style>\r\n\r\n<div id=\"leeyee-access-control-guide\">\r\n  <p class=\"ac-intro\">\r\n    An access control system can contain AC power, low-voltage DC power, Wiegand reader wiring, OSDP or RS-485 communication, monitored inputs, electric-lock outputs, Ethernet and PoE. These circuits do not share the same voltage, current or signal characteristics, so they should not be protected with one generic surge protective device.\r\n  <\/p>\r\n\r\n  <p>\r\n    This guide helps weak-current contractors, access control integrators, security engineers and project buyers identify the possible surge paths, select the correct SPD category and decide whether protection should be installed at the controller, the field device or both ends of the cable.\r\n  <\/p>\r\n\r\n  <section class=\"ac-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 of Contents<\/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\/es\/access-control-surge-protection\/#quick-answer\" >Quick Answer<\/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\/es\/access-control-surge-protection\/#which-access-control-lines-should-be-assessed\" >Which Access Control Lines Should Be Assessed?<\/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\/es\/access-control-surge-protection\/#how-can-surges-enter-an-access-control-system\" >How Can Surges Enter an Access Control System?<\/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\/es\/access-control-surge-protection\/#how-should-the-controller-power-supply-be-protected\" >How Should the Controller Power Supply Be Protected?<\/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\/es\/access-control-surge-protection\/#how-should-card-reader-lines-be-protected\" >How Should Card-Reader Lines Be Protected?<\/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\/es\/access-control-surge-protection\/#how-should-door-contacts-rex-and-tamper-inputs-be-assessed\" >How Should Door Contacts, REX and Tamper Inputs Be Assessed?<\/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\/es\/access-control-surge-protection\/#how-should-electric-locks-and-door-strikes-be-protected\" >How Should Electric Locks and Door Strikes Be Protected?<\/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\/es\/access-control-surge-protection\/#how-should-ethernet-and-poe-access-control-devices-be-protected\" >How Should Ethernet and PoE Access Control Devices Be Protected?<\/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\/es\/access-control-surge-protection\/#should-the-spd-be-installed-at-the-controller-or-field-device\" >Should the SPD Be Installed at the Controller or Field Device?<\/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\/es\/access-control-surge-protection\/#what-installation-details-affect-protection-performance\" >What Installation Details Affect Protection Performance?<\/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\/es\/access-control-surge-protection\/#which-standards-and-certificates-should-buyers-verify\" >Which Standards and Certificates Should Buyers Verify?<\/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\/es\/access-control-surge-protection\/#access-control-spd-selection-process\" >Access Control SPD Selection Process<\/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\/es\/access-control-surge-protection\/#typical-engineering-scenarios\" >Typical Engineering Scenarios<\/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\/es\/access-control-surge-protection\/#common-selection-and-installation-mistakes\" >Common Selection and Installation Mistakes<\/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\/es\/access-control-surge-protection\/#before-ordering-access-control-spds\" >Before Ordering Access Control SPDs<\/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\/es\/access-control-surge-protection\/#how-leeyee-reviews-an-access-control-spd-configuration\" >How LEEYEE Reviews an Access Control SPD Configuration<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/es\/access-control-surge-protection\/#need-an-access-control-spd-configuration-review\" >Need an Access Control SPD Configuration Review?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/es\/access-control-surge-protection\/#frequently-asked-questions\" >Frequently Asked Questions<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/es\/access-control-surge-protection\/#related-technical-guides\" >Related Technical Guides<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/es\/access-control-surge-protection\/#references\" >References<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"quick-answer\"><\/span>Quick Answer<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      <strong>Access control surge protection should be designed line by line.<\/strong> Start with the controller power supply. Then assess every conductive cable connected to readers, door contacts, request-to-exit devices, electric locks, remote controllers, network switches and outdoor access terminals.\r\n    <\/p>\r\n\r\n    <ul class=\"ac-quick-list\">\r\n      <li>An AC SPD protects the mains supply path. It does not automatically protect field wiring or network ports.<\/li>\r\n      <li>A reader-line SPD must match the interface, conductor arrangement, working voltage and current.<\/li>\r\n      <li>A PoE SPD must support both the required Ethernet performance and the required PoE power configuration.<\/li>\r\n      <li>Outdoor, inter-building and exposed cables may justify protection at both ends, but effective local bonding is still required.<\/li>\r\n    <\/ul>\r\n\r\n    <p>\r\n      IEC 61643-21 covers SPDs connected to telecommunications and signalling networks, including networks that provide power on the same line, such as PoE. IEC 61643-22 provides selection, location and coordination principles for these applications.\r\n      <a class=\"ac-ref\" href=\"#ac-ref-3\">[3]<\/a>\r\n      <a class=\"ac-ref\" href=\"#ac-ref-4\">[4]<\/a>\r\n    <\/p>\r\n  <\/section>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"which-access-control-lines-should-be-assessed\"><\/span>Which Access Control Lines Should Be Assessed?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>\r\n    The first engineering task is to create a circuit list. A single controlled door can have several independent conductive paths connected to the same controller.\r\n  <\/p>\r\n\r\n  <div class=\"ac-table-wrap\">\r\n    <p class=\"ac-table-note\">\r\n      The \u201cConfirm before selection\u201d column is the most important. It determines whether an SPD is electrically compatible with the connected circuit.\r\n    <\/p>\r\n\r\n    <table class=\"ac-table\">\r\n      <thead>\r\n        <tr>\r\n          <th scope=\"col\">Line group<\/th>\r\n          <th scope=\"col\">Typical equipment<\/th>\r\n          <th scope=\"col\">Confirm before selection<\/th>\r\n          <th scope=\"col\">SPD category to assess<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td data-label=\"Line group\"><strong>Controller AC supply<\/strong><\/td>\r\n          <td data-label=\"Typical equipment\">Control cabinet, power supply, UPS or PoE switch<\/td>\r\n          <td data-label=\"Confirm before selection\">System voltage, earthing system, installation position and backup protection<\/td>\r\n          <td data-label=\"SPD category to assess\">Low-voltage AC power SPD<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Line group\"><strong>Low-voltage DC power<\/strong><\/td>\r\n          <td data-label=\"Typical equipment\">Reader, keypad, lock, intercom or remote controller<\/td>\r\n          <td data-label=\"Confirm before selection\">Maximum operating voltage, polarity, current and conductor arrangement<\/td>\r\n          <td data-label=\"SPD category to assess\">DC power or combined power-and-signal SPD<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Line group\"><strong>Wiegand reader wiring<\/strong><\/td>\r\n          <td data-label=\"Typical equipment\">Card reader, keypad or biometric reader<\/td>\r\n          <td data-label=\"Confirm before selection\">D0, D1, power, common reference and auxiliary conductors<\/td>\r\n          <td data-label=\"SPD category to assess\">Interface-matched power and signal protection<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Line group\"><strong>OSDP or RS-485<\/strong><\/td>\r\n          <td data-label=\"Typical equipment\">Reader, peripheral module or remote door controller<\/td>\r\n          <td data-label=\"Confirm before selection\">Bus voltage, baud rate, topology, shielding and reader power<\/td>\r\n          <td data-label=\"SPD category to assess\">RS-485 or signalling-network SPD<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Line group\"><strong>Monitoring inputs<\/strong><\/td>\r\n          <td data-label=\"Typical equipment\">Door contact, tamper switch and request-to-exit device<\/td>\r\n          <td data-label=\"Confirm before selection\">Dry contact or supervised input, monitoring voltage, loop current and resistance thresholds<\/td>\r\n          <td data-label=\"SPD category to assess\">Low-leakage control-line SPD<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Line group\"><strong>Electric-lock output<\/strong><\/td>\r\n          <td data-label=\"Typical equipment\">Magnetic lock, electric strike or solenoid<\/td>\r\n          <td data-label=\"Confirm before selection\">AC or DC, voltage, load current, switching method and cable exposure<\/td>\r\n          <td data-label=\"SPD category to assess\">Load-compatible power or control-circuit SPD<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Line group\"><strong>Ethernet or PoE<\/strong><\/td>\r\n          <td data-label=\"Typical equipment\">IP reader, biometric terminal, door station or network controller<\/td>\r\n          <td data-label=\"Confirm before selection\">Data rate, PoE type, power demand, powered pairs and shielding<\/td>\r\n          <td data-label=\"SPD category to assess\">Ethernet or PoE-compatible SPD<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n\r\n    <p class=\"ac-table-conclusion\">\r\n      Procurement conclusion: do not begin with \u201cone 24 V access control SPD.\u201d Begin with a circuit list and the operating parameters of every exposed interface.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <figure class=\"ac-figure\">\r\n    <img loading=\"lazy\"\r\n      src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/access-control-system-surge-protection-architecture.webp\"\r\n      alt=\"Access control system surge protection architecture for power, reader, lock, control and PoE lines\"\r\n      width=\"1448\"\r\n      height=\"1086\"\r\n      loading=\"lazy\"\r\n      decoding=\"async\"\r\n    >\r\n    <figcaption>\r\n      A complete access control protection design may include separate protection points for the AC supply, reader power and data, monitored inputs, electric-lock circuit, OSDP or RS-485 bus and Ethernet or PoE connection. The final configuration must follow the actual equipment documents and site bonding design.\r\n    <\/figcaption>\r\n  <\/figure>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"how-can-surges-enter-an-access-control-system\"><\/span>How Can Surges Enter an Access Control System?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>\r\n    The building power supply is only one possible entry path. Conductive field wiring can also carry transient overvoltage into the controller or into a remote access terminal.\r\n  <\/p>\r\n\r\n  <ul class=\"ac-risk-list\">\r\n    <li><strong>Building AC supply:<\/strong> a transient can reach the control cabinet, power supply, UPS or PoE switch through the low-voltage distribution system.<\/li>\r\n    <li><strong>Outdoor reader cable:<\/strong> reader power and communication conductors can be exposed to induced or conducted transients.<\/li>\r\n    <li><strong>Perimeter gate or turnstile:<\/strong> field equipment is often connected through long cables and separate metal structures.<\/li>\r\n    <li><strong>Inter-building wiring:<\/strong> connected structures may not remain at the same electrical potential during a transient event.<\/li>\r\n    <li><strong>Ethernet and PoE cable:<\/strong> a remote IP terminal introduces a conductive data path and, in a PoE system, a power path.<\/li>\r\n    <li><strong>Local switching:<\/strong> relays, solenoids and electric locks can generate switching transients that must be distinguished from externally arriving surges.<\/li>\r\n  <\/ul>\r\n\r\n  <p>\r\n    IEC 62305-4 treats protection of electrical and electronic systems as a coordinated system problem. It addresses surge protection measures intended to reduce permanent failures caused by lightning electromagnetic impulse within structures.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-5\">[5]<\/a>\r\n  <\/p>\r\n\r\n  <div class=\"ac-callout\">\r\n    <h3>Do Not Judge Exposure Only by Equipment Location<\/h3>\r\n    <p>\r\n      An indoor controller can still be exposed through a cable connected to an outdoor reader, gate or remote building. The complete cable route, connected equipment and bonding path matter more than the controller\u2019s indoor location.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"how-should-the-controller-power-supply-be-protected\"><\/span>How Should the Controller Power Supply Be Protected?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <h3>AC Input Protection<\/h3>\r\n\r\n  <p>\r\n    The AC supply feeding an access control cabinet should be reviewed as part of the building\u2019s coordinated power-system surge protection design.\r\n  <\/p>\r\n\r\n  <p>\r\n    The selected AC SPD must match the actual system voltage and earthing arrangement. The project should also confirm SPD Type, maximum continuous operating voltage, voltage protection level, discharge-current ratings, connection mode, short-circuit conditions and required backup protection.\r\n  <\/p>\r\n\r\n  <p>\r\n    IEC 61643-11:2025 applies to SPDs connected to low-voltage AC power systems. IEC 61643-01:2024 provides common requirements and ratings used with the relevant product-specific parts.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-1\">[1]<\/a>\r\n    <a class=\"ac-ref\" href=\"#ac-ref-2\">[2]<\/a>\r\n  <\/p>\r\n\r\n  <div class=\"ac-warning\">\r\n    <h3>An AC SPD Does Not Protect Every Downstream Interface<\/h3>\r\n    <p>\r\n      A correctly selected mains SPD limits surges entering through the AC supply. A separate assessment is still required for reader, lock, RS-485, Ethernet and PoE wiring that can introduce another surge path.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <h3>Low-Voltage DC Field Power<\/h3>\r\n\r\n  <p>\r\n    Readers, locks and remote peripherals commonly use low-voltage DC supplies. The exact operating range must be taken from the connected equipment documentation.\r\n  <\/p>\r\n\r\n  <p>\r\n    The SPD maximum continuous operating voltage must remain compatible with the highest normal circuit voltage. For a device installed in series, the permitted continuous current and series resistance must also suit the connected load.\r\n  <\/p>\r\n\r\n  <p>\r\n    Battery-backed supplies require additional care because the real operating voltage can be higher than the nominal label during charging. Confirm the normal voltage range, battery charging voltage and equipment tolerance before approving the SPD.\r\n  <\/p>\r\n\r\n  <p class=\"ac-meaning\">\r\n    <strong>Buyer meaning:<\/strong> \u201c12 V SPD\u201d or \u201c24 V SPD\u201d is not a complete specification. The buyer must also identify whether the circuit carries DC power, reader data, RS-485 communication, a supervised input or a combination of functions.\r\n  <\/p>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"how-should-card-reader-lines-be-protected\"><\/span>How Should Card-Reader Lines Be Protected?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>\r\n    Wiegand, OSDP and Ethernet readers may perform a similar access-control function, but their electrical interfaces are different. The SPD must be selected for the interface rather than for the general term \u201ccard reader.\u201d\r\n  <\/p>\r\n\r\n  <h3>Wiegand Reader Circuits<\/h3>\r\n\r\n  <p>\r\n    A Wiegand reader connection can include power, ground, D0, D1 and additional conductors for functions such as LED, buzzer, tamper or hold control. The exact wire functions vary by reader.\r\n  <\/p>\r\n\r\n  <p>\r\n    HID\u2019s Signo 25B installation guide, for example, documents separate Wiegand, RS-485, supervised-input, DC-power and Ethernet connections. This demonstrates why the exact device model and wiring document must be reviewed before an SPD is selected.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-7\">[7]<\/a>\r\n  <\/p>\r\n\r\n  <p>\r\n    Confirm the reader supply voltage, maximum current, signal reference, conductor count and auxiliary functions. A protector that adds excessive loading or leaves an exposed conductor unprotected may not be suitable.\r\n  <\/p>\r\n\r\n  <h3>OSDP and RS-485 Readers<\/h3>\r\n\r\n  <p>\r\n    The Security Industry Association describes OSDP as an open communications standard used between access-control panels and peripheral devices such as readers. It offers a more capable alternative to legacy Wiegand and is commonly implemented over an RS-485 physical connection.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-6\">[6]<\/a>\r\n  <\/p>\r\n\r\n  <p>\r\n    An OSDP installation may include a communication pair, reader power, a common reference and shielding. The designer should confirm the bus topology, baud rate, cable type, grounding arrangement and whether multiple devices share the bus.\r\n  <\/p>\r\n\r\n  <p>\r\n    A product labelled \u201cRS-485 SPD\u201d is not automatically suitable for every OSDP installation. Its working voltage, protection modes, series impedance, capacitance, conductor arrangement and bonding method still require verification.\r\n  <\/p>\r\n\r\n  <h3>Proprietary and Multifunction Terminals<\/h3>\r\n\r\n  <p>\r\n    Some biometric readers, keypads, video door stations and remote controllers combine several functions in one cable or connector.\r\n  <\/p>\r\n\r\n  <p>\r\n    When the interface limits are not documented, request the controller and reader wiring diagrams. Sample validation may be necessary before a large project or OEM order, particularly when allowable leakage, capacitance and series resistance are unknown.\r\n  <\/p>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"how-should-door-contacts-rex-and-tamper-inputs-be-assessed\"><\/span>How Should Door Contacts, REX and Tamper Inputs Be Assessed?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>\r\n    A door contact may be described as a dry-contact device, but the connected controller can still apply a small monitoring voltage or current to identify normal, alarm, open-circuit, short-circuit or tamper conditions.\r\n  <\/p>\r\n\r\n  <p>\r\n    Some systems use supervised inputs and end-of-line resistance. HID\u2019s Signo installation documentation provides one example of supervised request-to-exit and door-position inputs.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-7\">[7]<\/a>\r\n  <\/p>\r\n\r\n  <p>Before adding a control-line SPD, confirm:<\/p>\r\n\r\n  <ul>\r\n    <li>Open-circuit monitoring voltage<\/li>\r\n    <li>Normal loop current<\/li>\r\n    <li>Alarm, fault and tamper thresholds<\/li>\r\n    <li>End-of-line resistor arrangement<\/li>\r\n    <li>Number of conductors and shared commons<\/li>\r\n    <li>Maximum acceptable SPD leakage current<\/li>\r\n    <li>Maximum acceptable series resistance and capacitance<\/li>\r\n  <\/ul>\r\n\r\n  <p>\r\n    An incorrectly selected SPD can change the electrical conditions seen by the controller input. Short indoor loops do not automatically require a separate SPD, while outdoor, inter-building and exposed loops require a more detailed project assessment.\r\n  <\/p>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"how-should-electric-locks-and-door-strikes-be-protected\"><\/span>How Should Electric Locks and Door Strikes Be Protected?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>\r\n    Electric-lock circuits can experience two different types of transient problem. They should be evaluated separately.\r\n  <\/p>\r\n\r\n  <h3>Surges Arriving Through the Field Cable<\/h3>\r\n\r\n  <p>\r\n    A cable connected to an outdoor magnetic lock, electric strike, gate or solenoid can carry an externally generated transient toward the controller.\r\n  <\/p>\r\n\r\n  <p>\r\n    The field-line SPD must match the circuit voltage, load current, polarity where applicable, switching arrangement and installation environment. The controller output rating and lock manufacturer\u2019s instructions remain the final approval references.\r\n  <\/p>\r\n\r\n  <h3>Inductive Switching Transients<\/h3>\r\n\r\n  <p>\r\n    A lock or strike coil can generate a local transient when current is interrupted. Depending on the equipment, the manufacturer may specify a diode, MOV, TVS or another suppression method.\r\n  <\/p>\r\n\r\n  <p>\r\n    Allegion installation documents for reader-controllers and electric strikes distinguish inductive-load suppression from protection against other transient voltages. They also require the suppression method to suit the actual device and circuit.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-8\">[8]<\/a>\r\n  <\/p>\r\n\r\n  <div class=\"ac-warning\">\r\n    <h3>Field-Line Protection Is Not the Same as Coil Suppression<\/h3>\r\n    <p>\r\n      A field-line SPD limits transient overvoltage entering through the cable. A manufacturer-specified suppression component controls the switching transient generated by the lock itself. A project may require both, but neither should be presented as an automatic replacement for the other.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"how-should-ethernet-and-poe-access-control-devices-be-protected\"><\/span>How Should Ethernet and PoE Access Control Devices Be Protected?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>\r\n    IP readers, biometric terminals, video door stations and networked controllers may use Ethernet or PoE. In a PoE system, communication and DC power share the structured cabling system.\r\n  <\/p>\r\n\r\n  <p>\r\n    IEC 61643-21:2025 explicitly includes telecommunications and signalling networks that provide power on the same line, such as PoE.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-3\">[3]<\/a>\r\n  <\/p>\r\n\r\n  <p>\r\n    Ethernet and PoE requirements should be checked against the applicable IEEE 802.3 edition and project documentation. IEEE 802.3-2022 is the base Ethernet standard listed by IEEE Standards Association, while later amendments may also apply to the selected equipment.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-9\">[9]<\/a>\r\n  <\/p>\r\n\r\n  <div class=\"ac-table-wrap\">\r\n    <p class=\"ac-table-note\">\r\n      A PoE SPD must satisfy both sides of the interface: Ethernet transmission and DC power delivery.\r\n    <\/p>\r\n\r\n    <table class=\"ac-table\">\r\n      <thead>\r\n        <tr>\r\n          <th scope=\"col\">Parameter<\/th>\r\n          <th scope=\"col\">Why it matters<\/th>\r\n          <th scope=\"col\">Information to provide<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td data-label=\"Parameter\"><strong>Ethernet performance<\/strong><\/td>\r\n          <td data-label=\"Why it matters\">The SPD must not reduce the link performance below the project requirement<\/td>\r\n          <td data-label=\"Information to provide\">Required Ethernet data rate and cable category<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Parameter\"><strong>PoE type and power<\/strong><\/td>\r\n          <td data-label=\"Why it matters\">The current-carrying path must suit the PSE and powered device<\/td>\r\n          <td data-label=\"Information to provide\">PoE type, class or maximum device demand<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Parameter\"><strong>Powered pairs<\/strong><\/td>\r\n          <td data-label=\"Why it matters\">The protection circuit must cover the conductor arrangement used by the system<\/td>\r\n          <td data-label=\"Information to provide\">PSE model and powered-pair arrangement<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Parameter\"><strong>Shielding<\/strong><\/td>\r\n          <td data-label=\"Why it matters\">Shield continuity and bonding affect the installation method<\/td>\r\n          <td data-label=\"Information to provide\">Shielded or unshielded cable and connector format<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Parameter\"><strong>Mounting environment<\/strong><\/td>\r\n          <td data-label=\"Why it matters\">Outdoor equipment may require a suitable enclosure and environmental protection<\/td>\r\n          <td data-label=\"Information to provide\">Indoor cabinet, gate enclosure, wall box or exposed terminal<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n\r\n    <p class=\"ac-table-conclusion\">\r\n      Procurement conclusion: an RJ45 connector alone does not prove compatibility with the required Ethernet speed, PoE power or powered-pair arrangement.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <figure class=\"ac-figure\">\r\n    <img loading=\"lazy\"\r\n      src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/access-control-line-spd-selection-comparison.webp\"\r\n      alt=\"Comparison of SPD selection requirements for access control power, Wiegand, OSDP, lock, monitoring and PoE lines\"\r\n      width=\"1448\"\r\n      height=\"1086\"\r\n      loading=\"lazy\"\r\n      decoding=\"async\"\r\n    >\r\n    <figcaption>\r\n      AC power, low-voltage DC power, Wiegand, OSDP or RS-485, supervised inputs, electric-lock circuits and PoE require different confirmation data. The actual equipment datasheet takes priority over a generic application label.\r\n    <\/figcaption>\r\n  <\/figure>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"should-the-spd-be-installed-at-the-controller-or-field-device\"><\/span>Should the SPD Be Installed at the Controller or Field Device?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>\r\n    The installation position cannot be decided from cable length alone. It depends on the surge path, cable exposure, equipment at each end, bonding arrangement and project risk assessment.\r\n  <\/p>\r\n\r\n  <h3>Protection at Both Ends Deserves Particular Consideration When:<\/h3>\r\n\r\n  <ul>\r\n    <li>The reader, gate terminal, intercom or controller is installed outdoors.<\/li>\r\n    <li>The cable connects separate buildings or separately bonded structures.<\/li>\r\n    <li>The cable runs to a perimeter gate, guardhouse, turnstile or parking entrance.<\/li>\r\n    <li>Sensitive electronic equipment is connected at both ends.<\/li>\r\n    <li>The cable crosses different lightning protection or electromagnetic zones.<\/li>\r\n    <li>The project specification or equipment manufacturer requires protection at both ends.<\/li>\r\n  <\/ul>\r\n\r\n  <h3>A Dedicated Field-Side SPD May Not Be Required When:<\/h3>\r\n\r\n  <ul>\r\n    <li>The cable is short, fully indoor and remains inside one bonded zone.<\/li>\r\n    <li>Only one end contains sensitive electronic equipment.<\/li>\r\n    <li>The connected equipment has documented internal withstand or protection.<\/li>\r\n    <li>The project risk assessment concludes that additional field protection is unnecessary.<\/li>\r\n  <\/ul>\r\n\r\n  <p>\r\n    IEC 61643-22 addresses selection, operation, location and coordination of SPDs for telecommunications and signalling networks. IEC 62305-4 places these devices within a wider surge protection measures system.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-4\">[4]<\/a>\r\n    <a class=\"ac-ref\" href=\"#ac-ref-5\">[5]<\/a>\r\n  <\/p>\r\n\r\n  <div class=\"ac-callout\">\r\n    <h3>Two SPDs Still Require Effective Local Bonding<\/h3>\r\n    <p>\r\n      Installing an SPD at each end does not guarantee effective protection if either device lacks an appropriate bonding or earthing path. The discharge path must be reviewed together with the protected circuit.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <figure class=\"ac-figure\">\r\n    <img loading=\"lazy\"\r\n      src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/access-control-spd-installation-position-decision-flow.webp\"\r\n      alt=\"Decision flow for choosing controller-side or field-side SPD installation in an access control system\"\r\n      width=\"1448\"\r\n      height=\"1086\"\r\n      loading=\"lazy\"\r\n      decoding=\"async\"\r\n    >\r\n    <figcaption>\r\n      Use the cable route, connected equipment and available bonding points to decide between controller-side protection, protection at both ends and project-specific engineering review.\r\n    <\/figcaption>\r\n  <\/figure>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"what-installation-details-affect-protection-performance\"><\/span>What Installation Details Affect Protection Performance?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <h3>Place the SPD Close to the Protected Interface<\/h3>\r\n\r\n  <p>\r\n    The connection between the SPD and the protected port should be practical and direct. Excessive conductor length and poor routing can increase the voltage experienced by the equipment during a fast transient.\r\n  <\/p>\r\n\r\n  <p>\r\n    The final conductor arrangement must follow the SPD installation instructions and applicable project requirements. Do not apply one universal connection-length value to every AC, DC, signal and PoE device.\r\n  <\/p>\r\n\r\n  <h3>Provide a Suitable Bonding Path<\/h3>\r\n\r\n  <p>\r\n    The SPD needs a defined path for diverting surge current. A long, indirect or poorly connected bonding conductor can reduce the effectiveness of the protection arrangement.\r\n  <\/p>\r\n\r\n  <p>\r\n    For outdoor equipment or separate structures, confirm the local earthing and equipotential bonding design before approving a field-side SPD.\r\n  <\/p>\r\n\r\n  <h3>Separate Exposed and Protected Wiring<\/h3>\r\n\r\n  <p>\r\n    Avoid routing the protected output beside the unprotected incoming cable where practical. Closely parallel wiring can allow transient energy to couple back into the protected side.\r\n  <\/p>\r\n\r\n  <h3>Check Existing Protection<\/h3>\r\n\r\n  <p>\r\n    The installation may already contain an AC SPD at the distribution board, another SPD in the controller cabinet or internal protective components in the connected equipment.\r\n  <\/p>\r\n\r\n  <p>\r\n    Confirm the purpose and ratings of each device. Internal port protection should not be assumed to replace external protection unless the equipment documentation clearly supports that conclusion.\r\n  <\/p>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"which-standards-and-certificates-should-buyers-verify\"><\/span>Which Standards and Certificates Should Buyers Verify?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <p>\r\n    The relevant document depends on the circuit being protected. One certificate should not be assumed to cover AC power, low-voltage control lines and Ethernet or PoE products at the same time.\r\n  <\/p>\r\n\r\n  <div class=\"ac-table-wrap\">\r\n    <table class=\"ac-table\">\r\n      <thead>\r\n        <tr>\r\n          <th scope=\"col\">Protection area<\/th>\r\n          <th scope=\"col\">Document to assess<\/th>\r\n          <th scope=\"col\">Buyer verification<\/th>\r\n        <\/tr>\r\n      <\/thead>\r\n      <tbody>\r\n        <tr>\r\n          <td data-label=\"Protection area\"><strong>AC power SPD<\/strong><\/td>\r\n          <td data-label=\"Document to assess\">IEC 61643-11 and the applicable national adoption or project specification<\/td>\r\n          <td data-label=\"Buyer verification\">Exact model, voltage, SPD Type, protection modes, ratings and certificate scope<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Protection area\"><strong>Signal, control and PoE SPD<\/strong><\/td>\r\n          <td data-label=\"Document to assess\">IEC 61643-21, with IEC 61643-22 used for application guidance<\/td>\r\n          <td data-label=\"Buyer verification\">Exact interface, voltage, current, transmission performance and tested model range<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Protection area\"><strong>North American data circuits<\/strong><\/td>\r\n          <td data-label=\"Document to assess\">UL 497B may be relevant to protectors for data communications and fire-alarm circuits<\/td>\r\n          <td data-label=\"Buyer verification\">Confirm the exact product listing and category in current UL certification records<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Protection area\"><strong>Ethernet and PoE interface<\/strong><\/td>\r\n          <td data-label=\"Document to assess\">Applicable IEEE 802.3 edition, amendments and equipment documentation<\/td>\r\n          <td data-label=\"Buyer verification\">Data rate, PoE type, class, powered pairs and maximum current<\/td>\r\n        <\/tr>\r\n        <tr>\r\n          <td data-label=\"Protection area\"><strong>Access control equipment<\/strong><\/td>\r\n          <td data-label=\"Document to assess\">Controller, reader, lock and network-device installation documents<\/td>\r\n          <td data-label=\"Buyer verification\">Port limits, wiring arrangement, suppression method and grounding instructions<\/td>\r\n        <\/tr>\r\n      <\/tbody>\r\n    <\/table>\r\n\r\n    <p class=\"ac-table-conclusion\">\r\n      Certificate conclusion: verify the certificate owner, exact model number, tested ratings, issue status and scope. A logo on a brochure is not enough evidence.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <p>\r\n    UL 497B is listed by UL Standards &amp; Engagement as a standard covering protectors for data communications and fire-alarm circuits. Applicability still depends on the exact product and intended installation.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-10\">[10]<\/a>\r\n  <\/p>\r\n\r\n  <p>\r\n    For a North American project, the buyer should check the exact certification record in UL Product iQ or the relevant certification database rather than relying only on a supplier statement.\r\n    <a class=\"ac-ref\" href=\"#ac-ref-10\">[10]<\/a>\r\n  <\/p>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"access-control-spd-selection-process\"><\/span>Access Control SPD Selection Process<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <ol class=\"ac-steps\">\r\n    <li>\r\n      <strong>Draw the system architecture.<\/strong><br>\r\n      Mark the distribution board, power supply, controller, readers, locks, monitoring devices, network switch and every conductive field cable.\r\n    <\/li>\r\n    <li>\r\n      <strong>Classify each circuit.<\/strong><br>\r\n      Identify AC power, DC power, Wiegand, OSDP or RS-485, supervised contact, lock output, Ethernet or PoE.\r\n    <\/li>\r\n    <li>\r\n      <strong>Record the electrical limits.<\/strong><br>\r\n      Confirm maximum operating voltage, load current, signal level, data rate, conductor count, shielding and allowable line loading.\r\n    <\/li>\r\n    <li>\r\n      <strong>Assess the cable route.<\/strong><br>\r\n      Check whether the cable is indoor, outdoor, inter-building, near power conductors or connected to a separate metal structure.\r\n    <\/li>\r\n    <li>\r\n      <strong>Select the SPD category.<\/strong><br>\r\n      Choose an AC power SPD, DC power SPD, signalling SPD, RS-485 SPD, control-line SPD or PoE SPD according to the circuit.\r\n    <\/li>\r\n    <li>\r\n      <strong>Choose the protection location.<\/strong><br>\r\n      Decide whether protection is needed at the controller, building entry, field equipment or both ends.\r\n    <\/li>\r\n    <li>\r\n      <strong>Verify compatibility and documents.<\/strong><br>\r\n      Check bonding, mounting, leakage, resistance, bandwidth, PoE power, certificate scope and equipment instructions.\r\n    <\/li>\r\n    <li>\r\n      <strong>Complete project approval.<\/strong><br>\r\n      Review the wiring diagram, product datasheet and sample performance before a large order or OEM release.\r\n    <\/li>\r\n  <\/ol>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"typical-engineering-scenarios\"><\/span>Typical Engineering Scenarios<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <div class=\"ac-scenario\">\r\n    <h3>Indoor Office Door<\/h3>\r\n    <p>\r\n      The controller and reader are inside the same building, and the field cable remains within one bonded area. Begin with the AC supply protection and cable-route assessment. A separate reader-line SPD should be decided from the equipment withstand and project risk rather than added automatically.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <div class=\"ac-scenario\">\r\n    <h3>Outdoor Perimeter Reader<\/h3>\r\n    <p>\r\n      The reader is mounted outside while the controller remains indoors. Assess the reader power and communication conductors separately. Protection at the controller and near the outdoor reader may be appropriate when effective local bonding is available.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <div class=\"ac-scenario\">\r\n    <h3>PoE Biometric Terminal at a Gate<\/h3>\r\n    <p>\r\n      Confirm the Ethernet data rate, PoE type, maximum power, cable shielding and outdoor enclosure. Review the PoE switch side, building entry and field terminal according to the cable route and bonding design.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <div class=\"ac-scenario\">\r\n    <h3>Inter-Building Access Controller<\/h3>\r\n    <p>\r\n      Conductive wiring between structures can expose equipment to differences in electrical potential. Review every power, communication and control path together with the earthing and bonding design at both buildings.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <div class=\"ac-scenario\">\r\n    <h3>Magnetic Lock with Supervised Door Contact<\/h3>\r\n    <p>\r\n      The lock output and door-contact input require different checks. The lock path must carry the load current and may require coil suppression, while the supervised input may require a low-leakage SPD that does not alter monitoring thresholds.\r\n    <\/p>\r\n  <\/div>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"common-selection-and-installation-mistakes\"><\/span>Common Selection and Installation Mistakes<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <ol>\r\n    <li><strong>Protecting only the AC input.<\/strong> Field and network cables can create separate surge entry paths.<\/li>\r\n    <li><strong>Using one 24 V SPD for every circuit.<\/strong> A lock output, Wiegand signal and OSDP bus do not have the same requirements.<\/li>\r\n    <li><strong>Treating Wiegand and OSDP as identical.<\/strong> Their communication and conductor arrangements differ.<\/li>\r\n    <li><strong>Choosing an RJ45 SPD only by connector appearance.<\/strong> Ethernet speed, PoE power and powered pairs must also match.<\/li>\r\n    <li><strong>Ignoring electric-lock current.<\/strong> A small signal SPD may not be suitable for the lock load.<\/li>\r\n    <li><strong>Adding excessive leakage to a supervised input.<\/strong> The SPD may affect normal, alarm or fault detection.<\/li>\r\n    <li><strong>Confusing coil suppression with field-line surge protection.<\/strong><\/li>\r\n    <li><strong>Installing two SPDs without suitable local bonding.<\/strong><\/li>\r\n    <li><strong>Routing protected and unprotected wiring together.<\/strong><\/li>\r\n    <li><strong>Accepting a certificate without checking the exact model and rating scope.<\/strong><\/li>\r\n  <\/ol>\r\n\r\n  <section class=\"ac-checklist\">\r\n    <h2><span class=\"ez-toc-section\" id=\"before-ordering-access-control-spds\"><\/span>Before Ordering Access Control SPDs<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      Send the following information to the supplier. A system diagram and circuit data are more useful than a controller photograph or a request for a generic access control surge protector.\r\n    <\/p>\r\n\r\n    <div class=\"ac-checklist-grid\">\r\n      <div class=\"ac-checklist-group\">\r\n        <h3>System Architecture<\/h3>\r\n        <ul>\r\n          <li>Controller and peripheral models<\/li>\r\n          <li>Number and type of doors<\/li>\r\n          <li>Indoor or outdoor equipment<\/li>\r\n          <li>Same-building or inter-building wiring<\/li>\r\n          <li>Cable route and approximate length<\/li>\r\n        <\/ul>\r\n      <\/div>\r\n\r\n      <div class=\"ac-checklist-group\">\r\n        <h3>Power Parameters<\/h3>\r\n        <ul>\r\n          <li>AC or DC<\/li>\r\n          <li>Nominal and maximum voltage<\/li>\r\n          <li>Maximum continuous or load current<\/li>\r\n          <li>Earthing arrangement<\/li>\r\n          <li>Battery-backed or non-backed supply<\/li>\r\n        <\/ul>\r\n      <\/div>\r\n\r\n      <div class=\"ac-checklist-group\">\r\n        <h3>Reader and Communication<\/h3>\r\n        <ul>\r\n          <li>Wiegand, OSDP, RS-485 or Ethernet<\/li>\r\n          <li>Reader supply voltage<\/li>\r\n          <li>Conductor count and wire functions<\/li>\r\n          <li>Baud rate or Ethernet data rate<\/li>\r\n          <li>Shielded or unshielded cable<\/li>\r\n        <\/ul>\r\n      <\/div>\r\n\r\n      <div class=\"ac-checklist-group\">\r\n        <h3>Lock and Monitoring Circuits<\/h3>\r\n        <ul>\r\n          <li>Lock type and operating current<\/li>\r\n          <li>AC or DC lock output<\/li>\r\n          <li>Dry-contact or supervised input<\/li>\r\n          <li>End-of-line resistor arrangement<\/li>\r\n          <li>Manufacturer suppression requirement<\/li>\r\n        <\/ul>\r\n      <\/div>\r\n\r\n      <div class=\"ac-checklist-group\">\r\n        <h3>PoE Details<\/h3>\r\n        <ul>\r\n          <li>PoE type or class<\/li>\r\n          <li>PSE and powered-device models<\/li>\r\n          <li>Maximum device power<\/li>\r\n          <li>Required data rate<\/li>\r\n          <li>Cable category and shielding<\/li>\r\n        <\/ul>\r\n      <\/div>\r\n\r\n      <div class=\"ac-checklist-group\">\r\n        <h3>Procurement Requirements<\/h3>\r\n        <ul>\r\n          <li>DIN-rail, panel or inline mounting<\/li>\r\n          <li>Required standard or certificate<\/li>\r\n          <li>Quantity<\/li>\r\n          <li>OEM label and packaging<\/li>\r\n          <li>Datasheet and sample approval needs<\/li>\r\n        <\/ul>\r\n      <\/div>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section class=\"ac-review\">\r\n    <h2><span class=\"ez-toc-section\" id=\"how-leeyee-reviews-an-access-control-spd-configuration\"><\/span>How LEEYEE Reviews an Access Control SPD Configuration<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      An access control project should be reviewed circuit by circuit. LEEYEE does not treat one generic product name as proof that every interface is compatible.\r\n    <\/p>\r\n\r\n    <div class=\"ac-review-grid\">\r\n      <div class=\"ac-review-item\">\r\n        <h3>1. Circuit Identification<\/h3>\r\n        <p>Separate the AC, DC, reader, monitored-input, lock, serial communication and PoE paths.<\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ac-review-item\">\r\n        <h3>2. Parameter Matching<\/h3>\r\n        <p>Compare working voltage, current, data performance, wiring mode and installation position.<\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ac-review-item\">\r\n        <h3>3. Document Verification<\/h3>\r\n        <p>Check the exact product datasheet, wiring instructions and model-specific certificate scope where required.<\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ac-review-item\">\r\n        <h3>4. Sample Approval<\/h3>\r\n        <p>Use sample or interface verification when a proprietary device or undocumented port creates uncertainty.<\/p>\r\n      <\/div>\r\n    <\/div>\r\n\r\n    <p class=\"ac-meaning\">\r\n      <strong>Project boundary:<\/strong> the final model cannot be selected from this article alone. The controller, reader, lock, network and site parameters must be confirmed for the actual project.\r\n    <\/p>\r\n  <\/section>\r\n\r\n  <section class=\"ac-cta\">\r\n    <h2><span class=\"ez-toc-section\" id=\"need-an-access-control-spd-configuration-review\"><\/span>Need an Access Control SPD Configuration Review?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      Share the controller voltage, reader interface, lock current, monitoring-input arrangement, PoE requirement, cable route and proposed installation positions. LEEYEE can review the required SPD categories for an OEM order or project configuration.\r\n    <\/p>\r\n\r\n    <button type=\"button\" class=\"leeyee-about-btn-light leeyee-site-popup-btn\" aria-label=\"Request a Quote\">\r\n      <span class=\"w-btn-label\">Request a Quote<\/span>\r\n    <\/button>\r\n\r\n    <p class=\"ac-brand-note\">\r\n      LEEYEE is a specialized surge protection and low-voltage protection supplier. CNSPD is LEEYEE\u2019s surge-protection-focused platform for global technical buyers.\r\n    <\/p>\r\n  <\/section>\r\n\r\n  <h2><span class=\"ez-toc-section\" id=\"frequently-asked-questions\"><\/span>Frequently Asked Questions<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n  <div class=\"ac-faq\">\r\n    <details>\r\n      <summary>Does every access control system need an SPD on every line?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          No. The requirement depends on the cable route, exposure, connected equipment, internal withstand, existing protection and project risk. Every conductive path should still be assessed.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Does a card-reader cable need surge protection?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          Protection is more likely to be required for outdoor, inter-building or exposed reader cables. The final decision should consider the interface, equipment withstand, cable route and bonding arrangement.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Can the same SPD protect Wiegand and OSDP readers?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          Only when the documented working voltage, conductor arrangement, series impedance, capacitance and protection modes suit both interfaces. Compatibility should not be assumed.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Does an OSDP reader use an RS-485 SPD?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          OSDP commonly uses an RS-485 physical connection, but the SPD must still match the actual bus voltage, baud rate, topology, grounding arrangement and reader power conductors.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Can a dry-contact input use any signal SPD?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          No. The controller may apply a supervision voltage or monitor resistance thresholds. SPD leakage, series resistance and capacitance must not interfere with normal, alarm, open-circuit or tamper detection.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Does a magnetic lock need surge protection?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          An exposed lock cable may require field-line surge protection. The lock may also require manufacturer-specified inductive-load suppression. These are separate functions.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Does a PoE access reader need an RJ45 SPD?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          Protection deserves particular consideration for outdoor, inter-building or exposed cabling. The SPD must support the required Ethernet speed, PoE power, powered pairs and shielding arrangement.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>Should an outdoor reader be protected at both ends?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          Protection at both ends may be appropriate when sensitive electronics are connected at both ends of an exposed cable. The decision must also consider local bonding, protection zones, equipment instructions and project risk.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n\r\n    <details>\r\n      <summary>What information is required for an OEM access control SPD order?<\/summary>\r\n      <div class=\"ac-faq-answer\">\r\n        <p>\r\n          Provide the system diagram, circuit voltage, maximum current, reader interface, monitoring method, Ethernet or PoE requirement, conductor count, cable route, installation position, required certification and quantity.\r\n        <\/p>\r\n      <\/div>\r\n    <\/details>\r\n  <\/div>\r\n\r\n  <section class=\"ac-related\">\r\n    <h2><span class=\"ez-toc-section\" id=\"related-technical-guides\"><\/span>Related Technical Guides<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n    <ul>\r\n      <li><a href=\"\/poe-surge-protector\/\">PoE Surge Protector Selection<\/a><\/li>\r\n      <li><a href=\"\/rj45-surge-protector-selection\/\">RJ45 Surge Protector Selection Guide<\/a><\/li>\r\n      <li><a href=\"\/cctv-surge-protection\/\">CCTV Surge Protection Guide<\/a><\/li>\r\n      <li><a href=\"\/outdoor-cctv-pole-surge-protection\/\">Outdoor CCTV Pole Surge Protection<\/a><\/li>\r\n      <li><a href=\"\/fire-alarm-system-surge-protection\/\">Fire Alarm System Surge Protection<\/a><\/li>\r\n    <\/ul>\r\n  <\/section>\r\n\r\n  <section class=\"ac-references\">\r\n    <h2><span class=\"ez-toc-section\" id=\"references\"><\/span>References<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <ol>\r\n      <li id=\"ac-ref-1\">\r\n        International Electrotechnical Commission, IEC 61643-01:2024, <em>Low-voltage surge protective devices \u2014 Part 01: General requirements<\/em>.\r\n        <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/65315\" target=\"_blank\" rel=\"noopener noreferrer\">Official IEC publication page<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-2\">\r\n        International Electrotechnical Commission, IEC 61643-11:2025, <em>Low-voltage surge protective devices \u2014 Part 11: Surge protective devices connected to low-voltage AC power systems \u2014 Requirements and test methods<\/em>.\r\n        <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/65314\" target=\"_blank\" rel=\"noopener noreferrer\">Official IEC publication page<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-3\">\r\n        International Electrotechnical Commission, IEC 61643-21:2025, <em>Surge protective devices connected to telecommunications and signalling networks \u2014 Performance requirements and test methods<\/em>.\r\n        <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/69085\" target=\"_blank\" rel=\"noopener noreferrer\">Official IEC publication page<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-4\">\r\n        International Electrotechnical Commission, IEC 61643-22:2015, <em>Low-voltage surge protective devices \u2014 Part 22: Surge protective devices connected to telecommunications and signalling networks \u2014 Selection and application principles<\/em>.\r\n        <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/22772\" target=\"_blank\" rel=\"noopener noreferrer\">Official IEC publication page<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-5\">\r\n        International Electrotechnical Commission, IEC 62305-4:2024, <em>Protection against lightning \u2014 Part 4: Electrical and electronic systems within structures<\/em>.\r\n        <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/29590\" target=\"_blank\" rel=\"noopener noreferrer\">Official IEC publication page<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-6\">\r\n        Security Industry Association, <em>Open Supervised Device Protocol (OSDP)<\/em> and <em>OSDP vs. Wiegand<\/em>.\r\n        <a href=\"https:\/\/www.securityindustry.org\/industry-standards\/open-supervised-device-protocol\/\" target=\"_blank\" rel=\"noopener noreferrer\">Official SIA OSDP page<\/a>;\r\n        <a href=\"https:\/\/www.securityindustry.org\/lp\/osdp-wiegand\/\" target=\"_blank\" rel=\"noopener noreferrer\">official comparison page<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-7\">\r\n        HID Global, <em>HID Signo 25B Biometric Reader\/Controller Installation Guide<\/em>, including documented Wiegand, RS-485, supervised-input, DC-power and Ethernet connections.\r\n        <a href=\"https:\/\/sdk.hidglobal.com\/sites\/default\/files\/dtk\/plt-04026-b.1-hid-signo-25b-installation-guide-en_0.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Official HID installation guide<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-8\">\r\n        Allegion, <em>ISONAS Pure IP Reader-Controller Installation and Wiring Guide<\/em> and Von Duprin <em>6400 Electric Strike Installation Instructions<\/em>, including manufacturer guidance on inductive-load suppression.\r\n        <a href=\"https:\/\/us.allegion.com\/content\/dam\/allegion-us-2\/web-files\/isonas\/technical-documents\/ISONAS_RC-04_Installation_and_Wiring_User_Guide_113884.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Official reader-controller guide<\/a>;\r\n        <a href=\"https:\/\/us.allegion.com\/content\/dam\/allegion-us-2\/web-files\/von-duprin-\/installation-documents\/Von_Duprin_6400_Electric_Strike_Installation_Instructions_106688.pdf.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">official electric-strike instructions<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-9\">\r\n        IEEE Standards Association, IEEE 802.3-2022, <em>IEEE Standard for Ethernet<\/em>.\r\n        <a href=\"https:\/\/standards.ieee.org\/ieee\/802.3\/10422\/\" target=\"_blank\" rel=\"noopener noreferrer\">Official IEEE standard page<\/a>.\r\n      <\/li>\r\n\r\n      <li id=\"ac-ref-10\">\r\n        UL Standards &amp; Engagement, UL 497B, <em>Protectors for Data Communications and Fire-Alarm Circuits<\/em>, and UL Solutions Product iQ certification database.\r\n        <a href=\"https:\/\/www.shopulstandards.com\/ProductDetail.aspx?UniqueKey=11977\" target=\"_blank\" rel=\"noopener noreferrer\">Official UL standard page<\/a>;\r\n        <a href=\"https:\/\/productiq.ulprospector.com\/\" target=\"_blank\" rel=\"noopener noreferrer\">UL Product iQ<\/a>.\r\n      <\/li>\r\n    <\/ol>\r\n  <\/section>\r\n<\/div>\r\n\r\n<script>\r\ndocument.addEventListener(\"DOMContentLoaded\", function () {\r\n  var btns = document.querySelectorAll(\".leeyee-site-popup-btn\");\r\n\r\n  btns.forEach(function (b) {\r\n    b.addEventListener(\"click\", function () {\r\n      var t = document.querySelector(\".w-popup.ush_popup_1 .w-popup-trigger\");\r\n\r\n      if (t) {\r\n        t.click();\r\n      } else {\r\n        window.open(\r\n          \"https:\/\/www.cnspd.com\/contact\/\",\r\n          \"_blank\",\r\n          \"noopener\"\r\n        );\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>\n\t\t","protected":false},"excerpt":{"rendered":"<p>An access control system can contain AC power, low-voltage DC power, Wiegand reader wiring, OSDP or RS-485 communication, monitored inputs, electric-lock outputs, Ethernet and PoE. These circuits do not share the same voltage, current or signal characteristics, so they should not be protected with one generic surge protective device. This guide helps weak-current contractors, access&#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-30565","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>Access Control Surge Protection: Power, Readers, Locks &amp; PoE<\/title>\n<meta name=\"description\" content=\"Learn how to select surge protection for access control panels, card readers, Wiegand, OSDP, electric locks, door contacts, Ethernet and PoE lines.\" \/>\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\/es\/access-control-surge-protection\/\" \/>\n<meta property=\"og:locale\" content=\"es_ES\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Access Control Surge Protection: Power, Readers, Locks &amp; PoE\" \/>\n<meta property=\"og:description\" content=\"Learn how to select surge protection for access control panels, card readers, Wiegand, OSDP, electric locks, door contacts, Ethernet and PoE lines.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.cnspd.com\/es\/access-control-surge-protection\/\" \/>\n<meta property=\"og:site_name\" content=\"Surge Protector, Surge Arrestor, Isolating Switch - 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