{"id":30017,"date":"2026-07-14T12:57:20","date_gmt":"2026-07-14T04:57:20","guid":{"rendered":"https:\/\/www.cnspd.com\/?p=30017"},"modified":"2026-07-14T14:32:37","modified_gmt":"2026-07-14T06:32:37","slug":"tn-s-system-spd-wiring-guide-3p-4p-and-3pn-selection","status":"publish","type":"post","link":"https:\/\/www.cnspd.com\/id\/tn-s-system-spd-wiring\/","title":{"rendered":"Panduan Pengkabelan SPD Sistem TN-S: Pemilihan 3P, 4P, dan 3P+N"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"30017\" class=\"elementor elementor-30017\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e0025a4 e-flex e-con-boxed e-con e-parent\" data-id=\"e0025a4\" 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-4706392 elementor-widget elementor-widget-html\" data-id=\"4706392\" 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\/* =========================================================\r\n   LEEYEE \u2014 TN-S SYSTEM SPD WIRING GUIDE\r\n   Article page for Impreza + WPBakery Custom HTML\r\n   WP page title provides the H1\r\n   ========================================================= *\/\r\n\r\n.ly-tns-page,\r\n.ly-tns-page *,\r\n.ly-tns-page *::before,\r\n.ly-tns-page *::after {\r\n  box-sizing: border-box;\r\n}\r\n\r\n.ly-tns-page {\r\n  --ly-blue: #004898;\r\n  --ly-blue-dark: #00366f;\r\n  --ly-blue-soft: #edf5ff;\r\n  --ly-blue-line: #c9ddf3;\r\n  --ly-text: #172234;\r\n  --ly-muted: #58677a;\r\n  --ly-border: #dce4ed;\r\n  --ly-bg: #f6f8fb;\r\n  --ly-white: #ffffff;\r\n  --ly-green: #167c4b;\r\n  --ly-green-soft: #ebf8f1;\r\n  --ly-orange: #a85508;\r\n  --ly-orange-soft: #fff6e9;\r\n  --ly-red: #b42318;\r\n  --ly-red-soft: #fff1f0;\r\n  --ly-shadow: 0 12px 32px rgba(22, 49, 78, 0.08);\r\n\r\n  width: 100%;\r\n  max-width: none;\r\n  margin: 0;\r\n  padding: 0;\r\n  overflow-x: hidden;\r\n  background: var(--ly-white);\r\n  color: var(--ly-text);\r\n  font-family: inherit;\r\n  font-size: 17px;\r\n  line-height: 1.72;\r\n}\r\n\r\n.ly-tns-page a {\r\n  color: var(--ly-blue);\r\n  text-decoration: underline;\r\n  text-decoration-thickness: 1px;\r\n  text-underline-offset: 3px;\r\n}\r\n\r\n.ly-tns-page a:hover,\r\n.ly-tns-page a:focus {\r\n  color: var(--ly-blue-dark);\r\n}\r\n\r\n.ly-tns-page p {\r\n  margin: 0 0 18px;\r\n}\r\n\r\n.ly-tns-page strong {\r\n  color: var(--ly-text);\r\n  font-weight: 750;\r\n}\r\n\r\n.ly-tns-shell {\r\n  width: calc(100% - 48px);\r\n  max-width: 1180px;\r\n  margin: 0 auto;\r\n  padding: 24px 0 72px;\r\n}\r\n\r\n.ly-tns-section {\r\n  margin-top: 64px;\r\n  scroll-margin-top: 110px;\r\n}\r\n\r\n.ly-tns-section > h2 {\r\n  margin: 0 0 18px;\r\n  color: var(--ly-text);\r\n  font-size: 34px;\r\n  line-height: 1.22;\r\n  letter-spacing: -0.025em;\r\n}\r\n\r\n.ly-tns-section > h3 {\r\n  margin: 32px 0 14px;\r\n  color: var(--ly-text);\r\n  font-size: 24px;\r\n  line-height: 1.3;\r\n}\r\n\r\n.ly-tns-lead {\r\n  max-width: 920px;\r\n  margin-bottom: 25px;\r\n  color: var(--ly-muted);\r\n  font-size: 19px;\r\n  line-height: 1.72;\r\n}\r\n\r\n.ly-tns-eyebrow {\r\n  display: inline-flex;\r\n  align-items: center;\r\n  gap: 9px;\r\n  margin-bottom: 14px;\r\n  color: var(--ly-blue);\r\n  font-size: 13px;\r\n  font-weight: 800;\r\n  line-height: 1.4;\r\n  letter-spacing: 0.1em;\r\n  text-transform: uppercase;\r\n}\r\n\r\n.ly-tns-eyebrow::before {\r\n  width: 28px;\r\n  height: 3px;\r\n  border-radius: 999px;\r\n  background: var(--ly-blue);\r\n  content: \"\";\r\n}\r\n\r\n\/* =========================================================\r\n   INTRO AND QUICK ANSWER\r\n   ========================================================= *\/\r\n\r\n.ly-tns-intro {\r\n  padding: 10px 0 4px;\r\n}\r\n\r\n.ly-tns-intro h2 {\r\n  max-width: 900px;\r\n  margin: 0 0 18px;\r\n  color: var(--ly-text);\r\n  font-size: 39px;\r\n  line-height: 1.17;\r\n  letter-spacing: -0.034em;\r\n}\r\n\r\n.ly-tns-intro-text {\r\n  max-width: 940px;\r\n  color: var(--ly-muted);\r\n  font-size: 19px;\r\n  line-height: 1.72;\r\n}\r\n\r\n.ly-tns-direct-answer {\r\n  margin-top: 28px;\r\n  padding: 29px;\r\n  border: 1px solid var(--ly-blue-line);\r\n  border-left: 6px solid var(--ly-blue);\r\n  border-radius: 16px;\r\n  background: linear-gradient(135deg, #f8fbff 0%, #edf5ff 100%);\r\n  box-shadow: var(--ly-shadow);\r\n}\r\n\r\n.ly-tns-direct-answer h2 {\r\n  margin: 0 0 14px;\r\n  color: var(--ly-blue-dark);\r\n  font-size: 28px;\r\n  line-height: 1.28;\r\n}\r\n\r\n.ly-tns-direct-answer > p {\r\n  max-width: 970px;\r\n  margin-bottom: 20px;\r\n  color: #31465d;\r\n  font-size: 17px;\r\n  line-height: 1.72;\r\n}\r\n\r\n.ly-tns-answer-grid {\r\n  display: grid;\r\n  grid-template-columns: repeat(2, minmax(0, 1fr));\r\n  gap: 13px;\r\n}\r\n\r\n.ly-tns-answer-item {\r\n  position: relative;\r\n  min-width: 0;\r\n  padding: 15px 15px 15px 46px;\r\n  border: 1px solid rgba(0, 72, 152, 0.13);\r\n  border-radius: 10px;\r\n  background: rgba(255, 255, 255, 0.86);\r\n  color: #34465b;\r\n  font-size: 15px;\r\n  line-height: 1.62;\r\n}\r\n\r\n.ly-tns-answer-item::before {\r\n  position: absolute;\r\n  top: 16px;\r\n  left: 15px;\r\n  display: flex;\r\n  align-items: center;\r\n  justify-content: center;\r\n  width: 21px;\r\n  height: 21px;\r\n  border-radius: 50%;\r\n  background: var(--ly-blue);\r\n  color: #fff;\r\n  content: \"\u2713\";\r\n  font-size: 12px;\r\n  font-weight: 800;\r\n}\r\n\r\n\/* Safety *\/\r\n.ly-tns-safety {\r\n  display: flex;\r\n  align-items: flex-start;\r\n  gap: 12px;\r\n  margin-top: 21px;\r\n  padding: 15px 17px;\r\n  border: 1px solid #efd5ae;\r\n  border-radius: 11px;\r\n  background: #fffaf2;\r\n  color: #684a21;\r\n  font-size: 14px;\r\n  line-height: 1.65;\r\n}\r\n\r\n.ly-tns-safety-icon {\r\n  flex: 0 0 auto;\r\n  display: flex;\r\n  align-items: center;\r\n  justify-content: center;\r\n  width: 24px;\r\n  height: 24px;\r\n  border-radius: 50%;\r\n  background: #f4ddb7;\r\n  color: #704700;\r\n  font-weight: 800;\r\n}\r\n\r\n\/* =========================================================\r\n   IMAGES\r\n   ========================================================= *\/\r\n\r\n.ly-tns-figure {\r\n  width: 100%;\r\n  margin: 31px 0;\r\n  padding: 11px;\r\n  overflow: hidden;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 16px;\r\n  background: var(--ly-white);\r\n  box-shadow: var(--ly-shadow);\r\n}\r\n\r\n.ly-tns-figure img {\r\n  display: block;\r\n  width: 100%;\r\n  max-width: 100%;\r\n  height: auto;\r\n  margin: 0;\r\n  border: 0;\r\n  border-radius: 10px;\r\n  object-fit: contain;\r\n}\r\n\r\n.ly-tns-figure figcaption {\r\n  margin: 0;\r\n  padding: 13px 10px 3px;\r\n  color: var(--ly-muted);\r\n  font-size: 14px;\r\n  line-height: 1.6;\r\n  text-align: center;\r\n}\r\n\r\n.ly-tns-figure.is-primary {\r\n  border-color: var(--ly-blue-line);\r\n  background: #f8fbff;\r\n}\r\n\r\n\/* =========================================================\r\n   DECISION TABLE\r\n   ========================================================= *\/\r\n\r\n.ly-tns-decision {\r\n  margin-top: 30px;\r\n}\r\n\r\n.ly-tns-decision h3 {\r\n  margin: 0 0 14px;\r\n  color: var(--ly-text);\r\n  font-size: 23px;\r\n  line-height: 1.3;\r\n}\r\n\r\n.ly-tns-table-note {\r\n  margin-top: -10px;\r\n  color: var(--ly-muted);\r\n  font-size: 14px;\r\n}\r\n\r\n\/* =========================================================\r\n   TABLE OF CONTENTS\r\n   ========================================================= *\/\r\n\r\n.ly-tns-toc {\r\n  margin-top: 34px;\r\n  padding: 24px 27px;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 14px;\r\n  background: var(--ly-bg);\r\n}\r\n\r\n.ly-tns-toc-title {\r\n  margin-bottom: 14px;\r\n  color: var(--ly-text);\r\n  font-size: 18px;\r\n  font-weight: 800;\r\n}\r\n\r\n.ly-tns-toc ol {\r\n  display: grid;\r\n  grid-template-columns: repeat(2, minmax(0, 1fr));\r\n  gap: 8px 32px;\r\n  margin: 0;\r\n  padding-left: 22px;\r\n}\r\n\r\n.ly-tns-toc li {\r\n  padding-left: 3px;\r\n  color: var(--ly-muted);\r\n  font-size: 15px;\r\n  line-height: 1.55;\r\n}\r\n\r\n.ly-tns-toc a {\r\n  color: #314158;\r\n  text-decoration: none;\r\n}\r\n\r\n.ly-tns-toc a:hover,\r\n.ly-tns-toc a:focus {\r\n  color: var(--ly-blue);\r\n  text-decoration: underline;\r\n}\r\n\r\n\/* =========================================================\r\n   TABLES\r\n   ========================================================= *\/\r\n\r\n.ly-tns-table-wrap {\r\n  width: 100%;\r\n  margin: 25px 0;\r\n  overflow-x: auto;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 13px;\r\n  background: var(--ly-white);\r\n  -webkit-overflow-scrolling: touch;\r\n}\r\n\r\n.ly-tns-table {\r\n  width: 100%;\r\n  min-width: 820px;\r\n  border-collapse: collapse;\r\n  border-spacing: 0;\r\n}\r\n\r\n.ly-tns-table th,\r\n.ly-tns-table td {\r\n  padding: 15px 16px;\r\n  border-right: 1px solid var(--ly-border);\r\n  border-bottom: 1px solid var(--ly-border);\r\n  text-align: left;\r\n  vertical-align: top;\r\n  font-size: 15px;\r\n  line-height: 1.58;\r\n}\r\n\r\n.ly-tns-table th:last-child,\r\n.ly-tns-table td:last-child {\r\n  border-right: 0;\r\n}\r\n\r\n.ly-tns-table tbody tr:last-child td {\r\n  border-bottom: 0;\r\n}\r\n\r\n.ly-tns-table thead th {\r\n  background: var(--ly-blue);\r\n  color: #fff;\r\n  font-weight: 750;\r\n}\r\n\r\n.ly-tns-table tbody tr:nth-child(even) {\r\n  background: #f8fafc;\r\n}\r\n\r\n.ly-tns-table strong {\r\n  display: block;\r\n  margin-bottom: 3px;\r\n}\r\n\r\n\/* =========================================================\r\n   CALLOUTS\r\n   ========================================================= *\/\r\n\r\n.ly-tns-callout {\r\n  margin: 24px 0;\r\n  padding: 21px 23px;\r\n  border-radius: 13px;\r\n  font-size: 16px;\r\n  line-height: 1.68;\r\n}\r\n\r\n.ly-tns-callout h3 {\r\n  margin: 0 0 8px;\r\n  font-size: 20px;\r\n  line-height: 1.35;\r\n}\r\n\r\n.ly-tns-callout p:last-child {\r\n  margin-bottom: 0;\r\n}\r\n\r\n.ly-tns-callout.is-blue {\r\n  border: 1px solid var(--ly-blue-line);\r\n  background: var(--ly-blue-soft);\r\n}\r\n\r\n.ly-tns-callout.is-green {\r\n  border: 1px solid #bee5d0;\r\n  background: var(--ly-green-soft);\r\n}\r\n\r\n.ly-tns-callout.is-orange {\r\n  border: 1px solid #efd2a9;\r\n  background: var(--ly-orange-soft);\r\n}\r\n\r\n.ly-tns-callout.is-red {\r\n  border: 1px solid #efc6c2;\r\n  background: var(--ly-red-soft);\r\n}\r\n\r\n\/* =========================================================\r\n   CONNECTION STEPS\r\n   ========================================================= *\/\r\n\r\n.ly-tns-connection-grid {\r\n  display: grid;\r\n  grid-template-columns: repeat(2, minmax(0, 1fr));\r\n  gap: 15px;\r\n  margin-top: 25px;\r\n}\r\n\r\n.ly-tns-connection-card {\r\n  position: relative;\r\n  min-width: 0;\r\n  padding: 20px 20px 20px 64px;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 12px;\r\n  background: #fff;\r\n}\r\n\r\n.ly-tns-connection-number {\r\n  position: absolute;\r\n  top: 20px;\r\n  left: 18px;\r\n  display: flex;\r\n  align-items: center;\r\n  justify-content: center;\r\n  width: 31px;\r\n  height: 31px;\r\n  border-radius: 8px;\r\n  background: var(--ly-blue);\r\n  color: #fff;\r\n  font-size: 14px;\r\n  font-weight: 800;\r\n}\r\n\r\n.ly-tns-connection-card h3 {\r\n  margin: 0 0 7px;\r\n  font-size: 18px;\r\n  line-height: 1.35;\r\n}\r\n\r\n.ly-tns-connection-card p {\r\n  margin: 0;\r\n  color: var(--ly-muted);\r\n  font-size: 14px;\r\n  line-height: 1.63;\r\n}\r\n\r\n\/* =========================================================\r\n   CHECK AND ERROR LISTS\r\n   ========================================================= *\/\r\n\r\n.ly-tns-check-list,\r\n.ly-tns-error-list {\r\n  display: grid;\r\n  gap: 11px;\r\n  margin: 22px 0 0;\r\n  padding: 0;\r\n  list-style: none;\r\n}\r\n\r\n.ly-tns-check-list li,\r\n.ly-tns-error-list li {\r\n  position: relative;\r\n  padding: 14px 16px 14px 49px;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 10px;\r\n  background: #fff;\r\n  color: #38485c;\r\n  line-height: 1.62;\r\n}\r\n\r\n.ly-tns-check-list li::before,\r\n.ly-tns-error-list li::before {\r\n  position: absolute;\r\n  top: 15px;\r\n  left: 16px;\r\n  display: flex;\r\n  align-items: center;\r\n  justify-content: center;\r\n  width: 23px;\r\n  height: 23px;\r\n  border-radius: 50%;\r\n  font-size: 13px;\r\n  font-weight: 800;\r\n}\r\n\r\n.ly-tns-check-list li::before {\r\n  background: var(--ly-green-soft);\r\n  color: var(--ly-green);\r\n  content: \"\u2713\";\r\n}\r\n\r\n.ly-tns-error-list li::before {\r\n  background: var(--ly-red-soft);\r\n  color: var(--ly-red);\r\n  content: \"!\";\r\n}\r\n\r\n\/* =========================================================\r\n   ORDERING CARDS\r\n   ========================================================= *\/\r\n\r\n.ly-tns-card-grid {\r\n  display: grid;\r\n  grid-template-columns: repeat(3, minmax(0, 1fr));\r\n  gap: 17px;\r\n  margin-top: 25px;\r\n}\r\n\r\n.ly-tns-card {\r\n  min-width: 0;\r\n  padding: 22px;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 13px;\r\n  background: #fff;\r\n  box-shadow: 0 8px 22px rgba(22, 49, 78, 0.05);\r\n}\r\n\r\n.ly-tns-card-label {\r\n  display: inline-flex;\r\n  margin-bottom: 12px;\r\n  padding: 5px 9px;\r\n  border-radius: 999px;\r\n  background: var(--ly-blue-soft);\r\n  color: var(--ly-blue);\r\n  font-size: 12px;\r\n  font-weight: 800;\r\n  line-height: 1.3;\r\n  letter-spacing: 0.04em;\r\n  text-transform: uppercase;\r\n}\r\n\r\n.ly-tns-card h3 {\r\n  margin: 0 0 9px;\r\n  font-size: 20px;\r\n  line-height: 1.35;\r\n}\r\n\r\n.ly-tns-card p {\r\n  margin: 0;\r\n  color: var(--ly-muted);\r\n  font-size: 15px;\r\n  line-height: 1.65;\r\n}\r\n\r\n\/* =========================================================\r\n   RFQ\r\n   ========================================================= *\/\r\n\r\n.ly-tns-rfq {\r\n  margin-top: 28px;\r\n  overflow: hidden;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 14px;\r\n  background: #fff;\r\n  box-shadow: var(--ly-shadow);\r\n}\r\n\r\n.ly-tns-rfq-head {\r\n  padding: 19px 22px;\r\n  background: var(--ly-blue);\r\n  color: #fff;\r\n}\r\n\r\n.ly-tns-rfq-head h3 {\r\n  margin: 0 0 5px;\r\n  color: #fff;\r\n  font-size: 22px;\r\n  line-height: 1.35;\r\n}\r\n\r\n.ly-tns-rfq-head p {\r\n  margin: 0;\r\n  color: rgba(255, 255, 255, 0.84);\r\n  font-size: 14px;\r\n}\r\n\r\n.ly-tns-rfq pre {\r\n  max-width: 100%;\r\n  margin: 0;\r\n  padding: 23px;\r\n  overflow-x: auto;\r\n  background: #f7f9fc;\r\n  color: #26384d;\r\n  font-family: Consolas, Monaco, \"Courier New\", monospace;\r\n  font-size: 14px;\r\n  line-height: 1.72;\r\n  white-space: pre-wrap;\r\n  word-break: break-word;\r\n}\r\n\r\n\/* =========================================================\r\n   CTA\r\n   ========================================================= *\/\r\n\r\n.ly-tns-cta {\r\n  margin-top: 64px;\r\n  padding: 35px;\r\n  border-radius: 17px;\r\n  background: linear-gradient(135deg, #003d82 0%, #0061bb 100%);\r\n  color: #fff;\r\n  box-shadow: 0 18px 42px rgba(0, 72, 152, 0.22);\r\n}\r\n\r\n.ly-tns-cta-grid {\r\n  display: grid;\r\n  grid-template-columns: minmax(0, 1fr) auto;\r\n  gap: 28px;\r\n  align-items: center;\r\n}\r\n\r\n.ly-tns-cta h2 {\r\n  margin: 0 0 9px;\r\n  color: #fff;\r\n  font-size: 29px;\r\n  line-height: 1.28;\r\n}\r\n\r\n.ly-tns-cta p {\r\n  max-width: 730px;\r\n  margin: 0;\r\n  color: rgba(255, 255, 255, 0.86);\r\n  font-size: 16px;\r\n  line-height: 1.68;\r\n}\r\n\r\n.ly-tns-btn,\r\n.ly-tns-page .ly-tns-btn {\r\n  display: inline-flex !important;\r\n  align-items: center !important;\r\n  justify-content: center !important;\r\n  min-width: 240px;\r\n  min-height: 51px;\r\n  margin: 0;\r\n  padding: 13px 21px !important;\r\n  border: 2px solid #fff !important;\r\n  border-radius: 8px !important;\r\n  background: #fff !important;\r\n  box-shadow: none !important;\r\n  color: var(--ly-blue) !important;\r\n  cursor: pointer;\r\n  font-family: inherit !important;\r\n  font-size: 15px !important;\r\n  font-weight: 800 !important;\r\n  line-height: 1.3 !important;\r\n  text-decoration: none !important;\r\n  white-space: nowrap;\r\n  opacity: 1 !important;\r\n  visibility: visible !important;\r\n  appearance: none;\r\n  -webkit-appearance: none;\r\n}\r\n\r\n.ly-tns-btn span,\r\n.ly-tns-page .ly-tns-btn span,\r\n.ly-tns-page .ly-tns-btn .w-btn-label {\r\n  display: inline-block !important;\r\n  color: var(--ly-blue) !important;\r\n  font-size: inherit !important;\r\n  font-weight: inherit !important;\r\n  line-height: inherit !important;\r\n  white-space: nowrap !important;\r\n  opacity: 1 !important;\r\n  visibility: visible !important;\r\n}\r\n\r\n.ly-tns-btn:hover,\r\n.ly-tns-btn:focus {\r\n  background: #eaf3fe !important;\r\n  color: var(--ly-blue-dark) !important;\r\n  transform: translateY(-1px);\r\n}\r\n\r\n.ly-tns-btn:hover span,\r\n.ly-tns-btn:focus span {\r\n  color: var(--ly-blue-dark) !important;\r\n}\r\n\r\n\/* =========================================================\r\n   RELATED LINKS\r\n   ========================================================= *\/\r\n\r\n.ly-tns-related {\r\n  display: grid;\r\n  grid-template-columns: repeat(3, minmax(0, 1fr));\r\n  gap: 14px;\r\n  margin-top: 23px;\r\n}\r\n\r\n.ly-tns-related a {\r\n  display: block;\r\n  min-height: 100%;\r\n  padding: 18px;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 10px;\r\n  background: #fff;\r\n  color: var(--ly-text);\r\n  font-size: 15px;\r\n  font-weight: 750;\r\n  line-height: 1.52;\r\n  text-decoration: none;\r\n}\r\n\r\n.ly-tns-related a:hover,\r\n.ly-tns-related a:focus {\r\n  border-color: var(--ly-blue);\r\n  color: var(--ly-blue);\r\n  box-shadow: 0 8px 18px rgba(0, 72, 152, 0.08);\r\n}\r\n\r\n\/* =========================================================\r\n   FAQ\r\n   ========================================================= *\/\r\n\r\n.ly-tns-faq {\r\n  display: grid;\r\n  gap: 11px;\r\n  margin-top: 24px;\r\n}\r\n\r\n.ly-tns-faq details {\r\n  overflow: hidden;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 10px;\r\n  background: #fff;\r\n}\r\n\r\n.ly-tns-faq summary {\r\n  position: relative;\r\n  padding: 16px 50px 16px 18px;\r\n  color: var(--ly-text);\r\n  cursor: pointer;\r\n  font-size: 16px;\r\n  font-weight: 750;\r\n  line-height: 1.5;\r\n  list-style: none;\r\n}\r\n\r\n.ly-tns-faq summary::-webkit-details-marker {\r\n  display: none;\r\n}\r\n\r\n.ly-tns-faq summary::after {\r\n  position: absolute;\r\n  top: 50%;\r\n  right: 17px;\r\n  color: var(--ly-blue);\r\n  content: \"+\";\r\n  font-size: 23px;\r\n  font-weight: 500;\r\n  transform: translateY(-50%);\r\n}\r\n\r\n.ly-tns-faq details[open] summary::after {\r\n  content: \"\u2212\";\r\n}\r\n\r\n.ly-tns-faq-answer {\r\n  padding: 0 18px 17px;\r\n  color: var(--ly-muted);\r\n  font-size: 15px;\r\n  line-height: 1.67;\r\n}\r\n\r\n.ly-tns-faq-answer p:last-child {\r\n  margin-bottom: 0;\r\n}\r\n\r\n\/* =========================================================\r\n   REFERENCES\r\n   ========================================================= *\/\r\n\r\n.ly-tns-references {\r\n  margin-top: 23px;\r\n  padding: 24px 27px;\r\n  border: 1px solid var(--ly-border);\r\n  border-radius: 12px;\r\n  background: var(--ly-bg);\r\n}\r\n\r\n.ly-tns-references ol {\r\n  margin: 0;\r\n  padding-left: 22px;\r\n}\r\n\r\n.ly-tns-references li {\r\n  margin-bottom: 11px;\r\n  padding-left: 4px;\r\n  overflow-wrap: anywhere;\r\n  color: var(--ly-muted);\r\n  font-size: 13px;\r\n  line-height: 1.65;\r\n}\r\n\r\n.ly-tns-references li:last-child {\r\n  margin-bottom: 0;\r\n}\r\n\r\n.ly-tns-ref {\r\n  font-size: 0.75em;\r\n  vertical-align: super;\r\n}\r\n\r\n.ly-tns-ref a {\r\n  font-weight: 750;\r\n  text-decoration: none;\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 DESKTOP 1440\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 1440px) {\r\n  .ly-tns-shell {\r\n    max-width: 1140px;\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 38px;\r\n  }\r\n\r\n  .ly-tns-figure {\r\n    margin-top: 30px;\r\n    margin-bottom: 30px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 DESKTOP 1366\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 1366px) {\r\n  .ly-tns-shell {\r\n    max-width: 1100px;\r\n  }\r\n\r\n  .ly-tns-section {\r\n    margin-top: 61px;\r\n  }\r\n\r\n  .ly-tns-section > h2 {\r\n    font-size: 33px;\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 37px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 DESKTOP 1280\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 1280px) {\r\n  .ly-tns-shell {\r\n    width: calc(100% - 42px);\r\n    max-width: 1050px;\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 36px;\r\n  }\r\n\r\n  .ly-tns-card {\r\n    padding: 20px;\r\n  }\r\n\r\n  .ly-tns-table th,\r\n  .ly-tns-table td {\r\n    padding: 14px 15px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 TABLET 1024\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 1024px) {\r\n  .ly-tns-page {\r\n    font-size: 16px;\r\n  }\r\n\r\n  .ly-tns-shell {\r\n    width: calc(100% - 38px);\r\n    padding-bottom: 62px;\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 34px;\r\n  }\r\n\r\n  .ly-tns-intro-text {\r\n    font-size: 18px;\r\n  }\r\n\r\n  .ly-tns-section > h2 {\r\n    font-size: 30px;\r\n  }\r\n\r\n  .ly-tns-card-grid {\r\n    grid-template-columns: repeat(2, minmax(0, 1fr));\r\n  }\r\n\r\n  .ly-tns-card-grid .ly-tns-card:last-child {\r\n    grid-column: 1 \/ -1;\r\n  }\r\n\r\n  .ly-tns-related {\r\n    grid-template-columns: repeat(2, minmax(0, 1fr));\r\n  }\r\n\r\n  .ly-tns-figure {\r\n    padding: 10px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 TABLET 912\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 912px) {\r\n  .ly-tns-shell {\r\n    width: calc(100% - 34px);\r\n  }\r\n\r\n  .ly-tns-direct-answer {\r\n    padding: 25px;\r\n  }\r\n\r\n  .ly-tns-cta {\r\n    padding: 31px;\r\n  }\r\n\r\n  .ly-tns-cta-grid {\r\n    grid-template-columns: 1fr;\r\n  }\r\n\r\n  .ly-tns-btn,\r\n  .ly-tns-page .ly-tns-btn {\r\n    justify-self: start;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 TABLET 820\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 820px) {\r\n  .ly-tns-intro h2 {\r\n    font-size: 32px;\r\n  }\r\n\r\n  .ly-tns-section {\r\n    margin-top: 55px;\r\n  }\r\n\r\n  .ly-tns-section > h2 {\r\n    font-size: 28px;\r\n  }\r\n\r\n  .ly-tns-answer-grid,\r\n  .ly-tns-connection-grid {\r\n    grid-template-columns: 1fr;\r\n  }\r\n\r\n  .ly-tns-toc ol {\r\n    grid-template-columns: 1fr;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 TABLET 768\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 768px) {\r\n  .ly-tns-shell {\r\n    width: calc(100% - 30px);\r\n    padding-top: 18px;\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 30px;\r\n  }\r\n\r\n  .ly-tns-intro-text,\r\n  .ly-tns-lead {\r\n    font-size: 17px;\r\n  }\r\n\r\n  .ly-tns-direct-answer {\r\n    padding: 22px;\r\n    border-left-width: 5px;\r\n  }\r\n\r\n  .ly-tns-direct-answer h2 {\r\n    font-size: 25px;\r\n  }\r\n\r\n  .ly-tns-card-grid,\r\n  .ly-tns-related {\r\n    grid-template-columns: 1fr;\r\n  }\r\n\r\n  .ly-tns-card-grid .ly-tns-card:last-child {\r\n    grid-column: auto;\r\n  }\r\n\r\n  .ly-tns-table th,\r\n  .ly-tns-table td {\r\n    padding: 13px 14px;\r\n  }\r\n\r\n  .ly-tns-figure {\r\n    padding: 9px;\r\n    border-radius: 13px;\r\n  }\r\n\r\n  .ly-tns-figure img {\r\n    border-radius: 8px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 600\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 600px) {\r\n  .ly-tns-page {\r\n    font-size: 15.5px;\r\n    line-height: 1.68;\r\n  }\r\n\r\n  .ly-tns-shell {\r\n    width: calc(100% - 26px);\r\n    padding-bottom: 52px;\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 28px;\r\n  }\r\n\r\n  .ly-tns-section {\r\n    margin-top: 49px;\r\n  }\r\n\r\n  .ly-tns-section > h2 {\r\n    font-size: 26px;\r\n  }\r\n\r\n  .ly-tns-section > h3 {\r\n    font-size: 21px;\r\n  }\r\n\r\n  .ly-tns-toc {\r\n    padding: 20px;\r\n  }\r\n\r\n  .ly-tns-cta {\r\n    padding: 26px;\r\n  }\r\n\r\n  .ly-tns-btn,\r\n  .ly-tns-page .ly-tns-btn {\r\n    width: 100%;\r\n    min-width: 0;\r\n    white-space: normal;\r\n  }\r\n\r\n  .ly-tns-btn span,\r\n  .ly-tns-page .ly-tns-btn span,\r\n  .ly-tns-page .ly-tns-btn .w-btn-label {\r\n    white-space: normal !important;\r\n    text-align: center;\r\n  }\r\n\r\n  .ly-tns-figure {\r\n    margin: 25px 0;\r\n    padding: 8px;\r\n  }\r\n\r\n  .ly-tns-figure figcaption {\r\n    padding-top: 11px;\r\n    font-size: 13px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 540\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 540px) {\r\n  .ly-tns-shell {\r\n    width: calc(100% - 24px);\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 27px;\r\n  }\r\n\r\n  .ly-tns-direct-answer {\r\n    padding: 19px;\r\n  }\r\n\r\n  .ly-tns-answer-item {\r\n    padding: 14px 13px 14px 43px;\r\n  }\r\n\r\n  .ly-tns-card {\r\n    padding: 19px;\r\n  }\r\n\r\n  .ly-tns-rfq pre {\r\n    padding: 19px;\r\n    font-size: 13px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 480\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 480px) {\r\n  .ly-tns-shell {\r\n    width: calc(100% - 22px);\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 26px;\r\n    line-height: 1.21;\r\n  }\r\n\r\n  .ly-tns-intro-text {\r\n    font-size: 16.5px;\r\n  }\r\n\r\n  .ly-tns-section > h2 {\r\n    font-size: 24px;\r\n  }\r\n\r\n  .ly-tns-direct-answer h2 {\r\n    font-size: 23px;\r\n  }\r\n\r\n  .ly-tns-callout {\r\n    padding: 18px;\r\n  }\r\n\r\n  .ly-tns-connection-card {\r\n    padding: 18px 17px 18px 59px;\r\n  }\r\n\r\n  .ly-tns-connection-number {\r\n    top: 18px;\r\n    left: 15px;\r\n  }\r\n\r\n  .ly-tns-cta {\r\n    margin-top: 53px;\r\n    padding: 23px;\r\n  }\r\n\r\n  .ly-tns-cta h2 {\r\n    font-size: 24px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 430\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 430px) {\r\n  .ly-tns-page {\r\n    font-size: 15px;\r\n  }\r\n\r\n  .ly-tns-shell {\r\n    width: calc(100% - 20px);\r\n  }\r\n\r\n  .ly-tns-eyebrow {\r\n    font-size: 11.5px;\r\n    letter-spacing: 0.08em;\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 25px;\r\n  }\r\n\r\n  .ly-tns-safety {\r\n    padding: 13px;\r\n  }\r\n\r\n  .ly-tns-direct-answer {\r\n    padding: 17px;\r\n  }\r\n\r\n  .ly-tns-table {\r\n    min-width: 760px;\r\n  }\r\n\r\n  .ly-tns-references {\r\n    padding: 19px;\r\n  }\r\n\r\n  .ly-tns-figure {\r\n    padding: 6px;\r\n  }\r\n\r\n  .ly-tns-figure figcaption {\r\n    padding: 10px 5px 2px;\r\n    font-size: 12.5px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 414\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 414px) {\r\n  .ly-tns-intro h2 {\r\n    font-size: 24.5px;\r\n  }\r\n\r\n  .ly-tns-section > h2 {\r\n    font-size: 23.5px;\r\n  }\r\n\r\n  .ly-tns-direct-answer h2 {\r\n    font-size: 22px;\r\n  }\r\n\r\n  .ly-tns-toc {\r\n    padding: 17px;\r\n  }\r\n\r\n  .ly-tns-related a {\r\n    padding: 16px;\r\n  }\r\n\r\n  .ly-tns-figure {\r\n    border-radius: 10px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 390\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 390px) {\r\n  .ly-tns-shell {\r\n    width: calc(100% - 18px);\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 23.5px;\r\n  }\r\n\r\n  .ly-tns-intro-text {\r\n    font-size: 16px;\r\n  }\r\n\r\n  .ly-tns-section {\r\n    margin-top: 45px;\r\n  }\r\n\r\n  .ly-tns-rfq-head {\r\n    padding: 17px;\r\n  }\r\n\r\n  .ly-tns-figure {\r\n    margin: 21px 0;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 375\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 375px) {\r\n  .ly-tns-intro h2 {\r\n    font-size: 23px;\r\n  }\r\n\r\n  .ly-tns-section > h2 {\r\n    font-size: 22.5px;\r\n  }\r\n\r\n  .ly-tns-direct-answer,\r\n  .ly-tns-card,\r\n  .ly-tns-callout {\r\n    padding: 15px;\r\n  }\r\n\r\n  .ly-tns-answer-item {\r\n    padding-left: 41px;\r\n  }\r\n\r\n  .ly-tns-answer-item::before {\r\n    left: 12px;\r\n  }\r\n\r\n  .ly-tns-cta {\r\n    padding: 20px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 360\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 360px) {\r\n  .ly-tns-shell {\r\n    width: calc(100% - 16px);\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 22.5px;\r\n  }\r\n\r\n  .ly-tns-faq summary {\r\n    padding: 14px 43px 14px 14px;\r\n    font-size: 15.5px;\r\n  }\r\n\r\n  .ly-tns-faq-answer {\r\n    padding: 0 14px 15px;\r\n  }\r\n\r\n  .ly-tns-figure {\r\n    padding: 5px;\r\n  }\r\n}\r\n\r\n\/* =========================================================\r\n   RESPONSIVE \u2014 MOBILE 320\r\n   ========================================================= *\/\r\n\r\n@media screen and (max-width: 320px) {\r\n  .ly-tns-page {\r\n    font-size: 14.5px;\r\n  }\r\n\r\n  .ly-tns-shell {\r\n    width: calc(100% - 14px);\r\n  }\r\n\r\n  .ly-tns-intro h2 {\r\n    font-size: 21px;\r\n  }\r\n\r\n  .ly-tns-section > h2 {\r\n    font-size: 21px;\r\n  }\r\n\r\n  .ly-tns-direct-answer h2 {\r\n    font-size: 19.5px;\r\n  }\r\n\r\n  .ly-tns-eyebrow::before {\r\n    width: 20px;\r\n  }\r\n\r\n  .ly-tns-cta h2 {\r\n    font-size: 21px;\r\n  }\r\n\r\n  .ly-tns-btn,\r\n  .ly-tns-page .ly-tns-btn {\r\n    padding-right: 11px !important;\r\n    padding-left: 11px !important;\r\n    font-size: 14px !important;\r\n  }\r\n}\r\n<\/style>\r\n\r\n<div class=\"ly-tns-page\">\r\n  <article class=\"ly-tns-shell\">\r\n\r\n    <!-- =====================================================\r\n         INTRO\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-intro\">\r\n      <div class=\"ly-tns-eyebrow\">\r\n        TN-S System \u00b7 Three-Phase Distribution \u00b7 OEM Selection\r\n      <\/div>\r\n\r\n      <div id=\"ez-toc-container\" class=\"ez-toc-v2_0_87 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\/id\/tn-s-system-spd-wiring\/#tn-s-spd-wiring-at-a-glance\" >TN-S SPD Wiring at a Glance<\/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\/id\/tn-s-system-spd-wiring\/#quick-answer-how-should-an-spd-be-wired-in-a-tn-s-system\" >Quick Answer: How Should an SPD Be Wired in a TN-S System?<\/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\/id\/tn-s-system-spd-wiring\/#what-is-a-tn-s-earthing-system\" >What Is a TN-S Earthing 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\/id\/tn-s-system-spd-wiring\/#l1-l2-l3-n-and-pe-in-a-tn-s-wiring-diagram\" >L1, L2, L3, N and PE in a TN-S Wiring Diagram<\/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\/id\/tn-s-system-spd-wiring\/#how-to-wire-an-spd-in-a-three-phase-tn-s-panel\" >How to Wire an SPD in a Three-Phase TN-S Panel<\/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\/id\/tn-s-system-spd-wiring\/#3p-vs-4p-vs-3pn-spd-for-a-tn-s-system\" >3P vs 4P vs 3P+N SPD for a TN-S System<\/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\/id\/tn-s-system-spd-wiring\/#40-vs-31-protection-in-a-tn-s-system\" >4+0 vs 3+1 Protection in a TN-S System<\/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\/id\/tn-s-system-spd-wiring\/#does-a-tn-s-system-need-n-pe-surge-protection\" >Does a TN-S System Need N-PE Surge Protection?<\/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\/id\/tn-s-system-spd-wiring\/#tn-s-system-spd-selection-process\" >TN-S System SPD Selection Process<\/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\/id\/tn-s-system-spd-wiring\/#parameters-to-confirm-before-ordering\" >Parameters to Confirm Before Ordering<\/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\/id\/tn-s-system-spd-wiring\/#rcd-position-and-spd-backup-protection\" >RCD Position and SPD Backup Protection<\/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\/id\/tn-s-system-spd-wiring\/#common-tn-s-spd-wiring-and-selection-errors\" >Common TN-S SPD Wiring and Selection Errors<\/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\/id\/tn-s-system-spd-wiring\/#tn-s-spd-oem-and-bulk-ordering-checklist\" >TN-S SPD OEM and Bulk Ordering Checklist<\/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\/id\/tn-s-system-spd-wiring\/#need-to-confirm-a-tn-s-spd-before-ordering\" >Need to confirm a TN-S SPD before ordering?<\/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\/id\/tn-s-system-spd-wiring\/#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-16\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/id\/tn-s-system-spd-wiring\/#tn-s-system-spd-wiring-faq\" >TN-S System SPD Wiring FAQ<\/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\/id\/tn-s-system-spd-wiring\/#technical-references\" >Technical References<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"tn-s-spd-wiring-at-a-glance\"><\/span>TN-S SPD Wiring at a Glance<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <p class=\"ly-tns-intro-text\">\r\n        In a three-phase TN-S system, the surge protective device is connected\r\n        in parallel with L1, L2, L3, N and PE according to the approved internal\r\n        circuit of the selected SPD. Neutral and protective earth remain separate\r\n        during normal operation.\r\n      <\/p>\r\n\r\n      <div class=\"ly-tns-direct-answer\">\r\n        <h2><span class=\"ez-toc-section\" id=\"quick-answer-how-should-an-spd-be-wired-in-a-tn-s-system\"><\/span>Quick Answer: How Should an SPD Be Wired in a TN-S System?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n        <p>\r\n          Where neutral is present, use a manufacturer-approved 4+0 \/ CT1 or\r\n          3+1 \/ CT2 arrangement. Connect the SPD close to the incoming busbars,\r\n          use the specified branch protection, and keep the SPD-to-PE connection\r\n          as short and direct as practicable. Do not select the device from pole\r\n          count alone.\r\n        <\/p>\r\n\r\n        <div class=\"ly-tns-answer-grid\">\r\n          <div class=\"ly-tns-answer-item\">\r\n            L1, L2, L3, N and PE remain separate conductors in the downstream\r\n            TN-S installation.\r\n          <\/div>\r\n\r\n          <div class=\"ly-tns-answer-item\">\r\n            A 3P SPD is normally considered only where no neutral conductor is\r\n            present or where the approved project design specifically requires it.\r\n          <\/div>\r\n\r\n          <div class=\"ly-tns-answer-item\">\r\n            A 4P device may use 4+0 \/ CT1, while a 3P+N device may use\r\n            3+1 \/ CT2. Check the internal circuit diagram.\r\n          <\/div>\r\n\r\n          <div class=\"ly-tns-answer-item\">\r\n            N-PE surge protection does not mean installing a permanent copper\r\n            link between the neutral and PE bars.\r\n          <\/div>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <figure class=\"ly-tns-figure is-primary\">\r\n        <img fetchpriority=\"high\"\r\n          src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/tn-s-system-spd-wiring-architecture.webp\"\r\n          alt=\"TN-S system SPD wiring architecture with separate L1 L2 L3 N and PE conductors\"\r\n          width=\"1600\"\r\n          height=\"900\"\r\n          loading=\"eager\"\r\n          decoding=\"async\"\r\n          fetchpriority=\"high\"\r\n        >\r\n        <figcaption>\r\n          <strong>Three-phase TN-S SPD wiring architecture:<\/strong>\r\n          the SPD is connected in parallel, N and PE remain separate, and the\r\n          PE connection is kept short and direct.\r\n        <\/figcaption>\r\n      <\/figure>\r\n\r\n      <div class=\"ly-tns-decision\">\r\n        <h3>Fast Selection by TN-S Panel Condition<\/h3>\r\n\r\n        <div class=\"ly-tns-table-wrap\">\r\n          <table class=\"ly-tns-table\">\r\n            <thead>\r\n              <tr>\r\n                <th>TN-S Panel Condition<\/th>\r\n                <th>Common Selection Direction<\/th>\r\n                <th>What the Buyer Must Confirm<\/th>\r\n              <\/tr>\r\n            <\/thead>\r\n\r\n            <tbody>\r\n              <tr>\r\n                <td>\r\n                  <strong>L1 \/ L2 \/ L3 without N<\/strong>\r\n                  Three-phase, three-wire circuit\r\n                <\/td>\r\n                <td>\r\n                  A project-specific 3P SPD may be used.\r\n                <\/td>\r\n                <td>\r\n                  Confirm that neutral is genuinely absent and check the exact\r\n                  product wiring diagram.\r\n                <\/td>\r\n              <\/tr>\r\n\r\n              <tr>\r\n                <td>\r\n                  <strong>L1 \/ L2 \/ L3 \/ N \/ PE<\/strong>\r\n                  Project specifies CT1\r\n                <\/td>\r\n                <td>\r\n                  4P \/ 4+0 \/ CT1 may be selected.\r\n                <\/td>\r\n                <td>\r\n                  Confirm L-PE and N-PE protection modes, Uc, Up, TOV behaviour\r\n                  and permitted RCD position.\r\n                <\/td>\r\n              <\/tr>\r\n\r\n              <tr>\r\n                <td>\r\n                  <strong>L1 \/ L2 \/ L3 \/ N \/ PE<\/strong>\r\n                  Project specifies CT2\r\n                <\/td>\r\n                <td>\r\n                  3P+N \/ 3+1 \/ CT2 may be selected.\r\n                <\/td>\r\n                <td>\r\n                  Confirm L-N protection, the N-PE component, I<sub>total<\/sub>,\r\n                  Up and manufacturer-approved TN-S application.\r\n                <\/td>\r\n              <\/tr>\r\n\r\n              <tr>\r\n                <td>\r\n                  <strong>The enquiry only says \u201cfour-pole SPD\u201d<\/strong>\r\n                  Internal circuit not provided\r\n                <\/td>\r\n                <td>\r\n                  Do not approve the model yet.\r\n                <\/td>\r\n                <td>\r\n                  Request the single-line diagram, internal SPD circuit and\r\n                  required protection modes.\r\n                <\/td>\r\n              <\/tr>\r\n            <\/tbody>\r\n          <\/table>\r\n        <\/div>\r\n\r\n        <p class=\"ly-tns-table-note\">\r\n          The market descriptions \u201c4P\u201d and \u201c3P+N\u201d do not always provide enough\r\n          information to confirm the internal protection circuit.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-tns-safety\">\r\n        <span class=\"ly-tns-safety-icon\">!<\/span>\r\n        <div>\r\n          <strong>Safety and scope:<\/strong>\r\n          Final wiring must follow the project single-line diagram, local\r\n          installation rules and the exact SPD manufacturer instructions.\r\n          Electrical installation work must be performed by qualified personnel.\r\n        <\/div>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         CONTENTS\r\n         ===================================================== -->\r\n    <nav class=\"ly-tns-toc\" aria-label=\"TN-S SPD wiring guide contents\">\r\n      <div class=\"ly-tns-toc-title\">Contents<\/div>\r\n\r\n      <ol>\r\n        <li><a href=\"#what-is-tns\">What Is a TN-S System?<\/a><\/li>\r\n        <li><a href=\"#tns-conductors\">L1, L2, L3, N and PE<\/a><\/li>\r\n        <li><a href=\"#how-to-wire\">How to Wire the SPD<\/a><\/li>\r\n        <li><a href=\"#3p-4p-3pn\">3P vs 4P vs 3P+N<\/a><\/li>\r\n        <li><a href=\"#4plus0-3plus1\">4+0 vs 3+1<\/a><\/li>\r\n        <li><a href=\"#npe-protection\">N-PE Protection<\/a><\/li>\r\n        <li><a href=\"#selection-process\">Selection Process<\/a><\/li>\r\n        <li><a href=\"#parameters\">Parameters to Confirm<\/a><\/li>\r\n        <li><a href=\"#rcd-backup\">RCD and Backup Protection<\/a><\/li>\r\n        <li><a href=\"#wiring-errors\">Common Errors<\/a><\/li>\r\n        <li><a href=\"#oem-checklist\">OEM Ordering Checklist<\/a><\/li>\r\n        <li><a href=\"#faq\">FAQ<\/a><\/li>\r\n      <\/ol>\r\n    <\/nav>\r\n\r\n    <!-- =====================================================\r\n         WHAT IS TN-S\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"what-is-tns\">\r\n      <h2><span class=\"ez-toc-section\" id=\"what-is-a-tn-s-earthing-system\"><\/span>What Is a TN-S Earthing System?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <p class=\"ly-tns-lead\">\r\n        In a TN-S system, the source neutral is earthed, while the neutral conductor\r\n        and protective earth conductor remain separate from the source to the loads.\r\n      <\/p>\r\n\r\n      <p>\r\n        A typical three-phase TN-S supply uses five conductors: L1, L2, L3, N and PE.\r\n        The neutral carries normal return current from phase-to-neutral loads. The PE\r\n        conductor provides protective bonding and the fault-current path and should\r\n        not carry normal load current.\r\n      <\/p>\r\n\r\n      <p>\r\n        This differs from TN-C, where neutral and protective functions are combined\r\n        in a PEN conductor, and TN-C-S, where a PEN conductor is separated into N and\r\n        PE at a defined point.\r\n      <\/p>\r\n\r\n      <div class=\"ly-tns-callout is-orange\">\r\n        <h3>Do not identify TN-S from conductor colours alone<\/h3>\r\n        <p>\r\n          Colours can vary by country, installation age and local practice. Confirm\r\n          the system from the project single-line diagram, supply documentation and\r\n          the actual N\/PE arrangement.\r\n        <\/p>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         CONDUCTORS\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"tns-conductors\">\r\n      <h2><span class=\"ez-toc-section\" id=\"l1-l2-l3-n-and-pe-in-a-tn-s-wiring-diagram\"><\/span>L1, L2, L3, N and PE in a TN-S Wiring Diagram<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <div class=\"ly-tns-table-wrap\">\r\n        <table class=\"ly-tns-table\">\r\n          <thead>\r\n            <tr>\r\n              <th>Conductor<\/th>\r\n              <th>Normal Function<\/th>\r\n              <th>SPD Selection Meaning<\/th>\r\n              <th>Common Mistake<\/th>\r\n            <\/tr>\r\n          <\/thead>\r\n\r\n          <tbody>\r\n            <tr>\r\n              <td>\r\n                <strong>L1 \/ L2 \/ L3<\/strong>\r\n                Phase conductors\r\n              <\/td>\r\n              <td>\r\n                Carry the three-phase supply voltage and load current.\r\n              <\/td>\r\n              <td>\r\n                Each phase requires the protection mode defined by the project\r\n                and SPD circuit.\r\n              <\/td>\r\n              <td>\r\n                Choosing a 3P SPD merely because the supply is described as\r\n                \u201cthree-phase.\u201d\r\n              <\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td>\r\n                <strong>N<\/strong>\r\n                Neutral conductor\r\n              <\/td>\r\n              <td>\r\n                Carries return current from phase-to-neutral loads.\r\n              <\/td>\r\n              <td>\r\n                Confirm whether the device provides L-N protection, N-PE\r\n                protection, or a combination of both.\r\n              <\/td>\r\n              <td>\r\n                Assuming all four-module SPDs protect neutral in the same way.\r\n              <\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td>\r\n                <strong>PE<\/strong>\r\n                Protective earth\r\n              <\/td>\r\n              <td>\r\n                Provides protective bonding and the surge discharge path.\r\n              <\/td>\r\n              <td>\r\n                The SPD-to-PE conductor should be short, direct and sized\r\n                according to the product instructions.\r\n              <\/td>\r\n              <td>\r\n                Mounting the SPD far from the PE bar and using a long looped lead.\r\n              <\/td>\r\n            <\/tr>\r\n          <\/tbody>\r\n        <\/table>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         HOW TO WIRE\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"how-to-wire\">\r\n      <h2><span class=\"ez-toc-section\" id=\"how-to-wire-an-spd-in-a-three-phase-tn-s-panel\"><\/span>How to Wire an SPD in a Three-Phase TN-S Panel<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <p class=\"ly-tns-lead\">\r\n        The SPD is connected in parallel with the incoming supply. Normal load\r\n        current does not pass through the SPD.\r\n      <\/p>\r\n\r\n      <div class=\"ly-tns-connection-grid\">\r\n        <div class=\"ly-tns-connection-card\">\r\n          <span class=\"ly-tns-connection-number\">1<\/span>\r\n          <h3>Confirm the supply arrangement<\/h3>\r\n          <p>\r\n            Verify L1, L2, L3, N and PE from the single-line diagram and confirm\r\n            that the system is TN-S at the SPD installation point.\r\n          <\/p>\r\n        <\/div>\r\n\r\n        <div class=\"ly-tns-connection-card\">\r\n          <span class=\"ly-tns-connection-number\">2<\/span>\r\n          <h3>Connect the SPD in parallel<\/h3>\r\n          <p>\r\n            Take the required phase and neutral connections from the incoming\r\n            conductors or busbars according to the SPD terminal diagram.\r\n          <\/p>\r\n        <\/div>\r\n\r\n        <div class=\"ly-tns-connection-card\">\r\n          <span class=\"ly-tns-connection-number\">3<\/span>\r\n          <h3>Install the specified branch protection<\/h3>\r\n          <p>\r\n            Use the fuse, MCB or other backup protection stated in the SPD\r\n            datasheet after checking the available short-circuit current.\r\n          <\/p>\r\n        <\/div>\r\n\r\n        <div class=\"ly-tns-connection-card\">\r\n          <span class=\"ly-tns-connection-number\">4<\/span>\r\n          <h3>Connect directly to the PE bar<\/h3>\r\n          <p>\r\n            Keep the earth path short, direct and free from unnecessary loops\r\n            or bends that increase inductive voltage.\r\n          <\/p>\r\n        <\/div>\r\n\r\n        <div class=\"ly-tns-connection-card\">\r\n          <span class=\"ly-tns-connection-number\">5<\/span>\r\n          <h3>Keep N and PE separate<\/h3>\r\n          <p>\r\n            Do not add a permanent copper link between the neutral bar and PE\r\n            bar in the downstream TN-S distribution board.\r\n          <\/p>\r\n        <\/div>\r\n\r\n        <div class=\"ly-tns-connection-card\">\r\n          <span class=\"ly-tns-connection-number\">6<\/span>\r\n          <h3>Complete the panel verification<\/h3>\r\n          <p>\r\n            Check terminal torque, lead length, backup protection, remote contact,\r\n            replacement module and the final approved drawing.\r\n          <\/p>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <div class=\"ly-tns-callout is-blue\">\r\n        <h3>Installation dimensions are product-specific<\/h3>\r\n        <p>\r\n          Do not copy terminal positions, conductor sizes or backup-device ratings\r\n          from a generic internet diagram. Use the exact installation instructions\r\n          for the ordered SPD model.\r\n        <\/p>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         3P VS 4P VS 3P+N\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"3p-4p-3pn\">\r\n      <h2><span class=\"ez-toc-section\" id=\"3p-vs-4p-vs-3pn-spd-for-a-tn-s-system\"><\/span>3P vs 4P vs 3P+N SPD for a TN-S System<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <p class=\"ly-tns-lead\">\r\n        Pole count describes the physical arrangement. It does not fully define\r\n        the internal surge protection paths.\r\n      <\/p>\r\n\r\n      <div class=\"ly-tns-table-wrap\">\r\n        <table class=\"ly-tns-table\">\r\n          <thead>\r\n            <tr>\r\n              <th>Market Description<\/th>\r\n              <th>Common Circuit Logic<\/th>\r\n              <th>Possible TN-S Use<\/th>\r\n              <th>Buyer Confirmation<\/th>\r\n            <\/tr>\r\n          <\/thead>\r\n\r\n          <tbody>\r\n            <tr>\r\n              <td>\r\n                <strong>3P SPD<\/strong>\r\n                Three-pole device\r\n              <\/td>\r\n              <td>\r\n                Protects three phase conductors without a dedicated neutral path.\r\n              <\/td>\r\n              <td>\r\n                A three-phase three-wire circuit or an approved project-specific design.\r\n              <\/td>\r\n              <td>\r\n                Confirm that neutral is absent at the SPD location.\r\n              <\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td>\r\n                <strong>4P SPD<\/strong>\r\n                Four-pole device\r\n              <\/td>\r\n              <td>\r\n                Often uses 4+0 \/ CT1, with L1, L2, L3 and N protected toward PE.\r\n              <\/td>\r\n              <td>\r\n                May be suitable where the manufacturer approves the device for TN-S.\r\n              <\/td>\r\n              <td>\r\n                Confirm the circuit symbol, protection modes, Uc, Up, TOV behaviour\r\n                and RCD arrangement.\r\n              <\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td>\r\n                <strong>3P+N SPD<\/strong>\r\n                Three phases plus neutral\r\n              <\/td>\r\n              <td>\r\n                Often uses 3+1 \/ CT2, with L-N protection plus a separate N-PE path.\r\n              <\/td>\r\n              <td>\r\n                Commonly available for TN-S systems.\r\n              <\/td>\r\n              <td>\r\n                Confirm the N-PE component, I<sub>total<\/sub>, Up and the exact\r\n                certified model.\r\n              <\/td>\r\n            <\/tr>\r\n          <\/tbody>\r\n        <\/table>\r\n      <\/div>\r\n\r\n      <div class=\"ly-tns-callout is-blue\">\r\n        <h3>This page is about TN-S wiring, not only product comparison<\/h3>\r\n        <p>\r\n          For a deeper comparison of product structures, see the\r\n          <a\r\n            href=\"https:\/\/www.cnspd.com\/3pn-spd-vs-4p-spd\/\"\r\n            target=\"_blank\"\r\n            rel=\"noopener\"\r\n          >3P+N SPD vs 4P SPD guide<\/a>.\r\n          This TN-S page focuses on how system type, conductor arrangement and\r\n          installation conditions affect the final wiring decision.\r\n        <\/p>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         4+0 VS 3+1\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"4plus0-3plus1\">\r\n      <h2><span class=\"ez-toc-section\" id=\"40-vs-31-protection-in-a-tn-s-system\"><\/span>4+0 vs 3+1 Protection in a TN-S System<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <p class=\"ly-tns-lead\">\r\n        Both protection arrangements may be available for TN-S systems, but they\r\n        create different surge paths.\r\n        <sup class=\"ly-tns-ref\"><a href=\"#ref-3\">[3]<\/a><\/sup>\r\n      <\/p>\r\n\r\n      <figure class=\"ly-tns-figure is-primary\">\r\n        <img loading=\"lazy\"\r\n          src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/tn-s-spd-4plus0-vs-3plus1-comparison.webp\"\r\n          alt=\"4 plus 0 vs 3 plus 1 SPD protection paths for a three-phase TN-S system\"\r\n          width=\"1600\"\r\n          height=\"900\"\r\n          loading=\"lazy\"\r\n          decoding=\"async\"\r\n        >\r\n        <figcaption>\r\n          <strong>4+0 \/ CT1 versus 3+1 \/ CT2:<\/strong>\r\n          check the internal protection circuit instead of relying only on the\r\n          number of poles or modules.\r\n        <\/figcaption>\r\n      <\/figure>\r\n\r\n      <div class=\"ly-tns-table-wrap\">\r\n        <table class=\"ly-tns-table\">\r\n          <thead>\r\n            <tr>\r\n              <th>Comparison<\/th>\r\n              <th>4+0 \/ X+0 \/ CT1<\/th>\r\n              <th>3+1 \/ X+1 \/ CT2<\/th>\r\n            <\/tr>\r\n          <\/thead>\r\n\r\n          <tbody>\r\n            <tr>\r\n              <td><strong>Phase protection path<\/strong><\/td>\r\n              <td>Commonly L1-PE, L2-PE and L3-PE<\/td>\r\n              <td>Commonly L1-N, L2-N and L3-N<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Neutral protection path<\/strong><\/td>\r\n              <td>N-PE protection element<\/td>\r\n              <td>Dedicated N-PE switching path<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Typical market description<\/strong><\/td>\r\n              <td>4P SPD<\/td>\r\n              <td>3P+N SPD<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Main purchasing check<\/strong><\/td>\r\n              <td>\r\n                L-PE and N-PE modes, TOV behaviour, Uc, Up and installation position\r\n              <\/td>\r\n              <td>\r\n                L-N mode, N-PE technology, I<sub>total<\/sub>, combined Up and\r\n                installation position\r\n              <\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Can it be used in TN-S?<\/strong><\/td>\r\n              <td>\r\n                Yes, when approved by the manufacturer and project specification\r\n              <\/td>\r\n              <td>\r\n                Yes, when approved by the manufacturer and project specification\r\n              <\/td>\r\n            <\/tr>\r\n          <\/tbody>\r\n        <\/table>\r\n      <\/div>\r\n\r\n      <div class=\"ly-tns-callout is-green\">\r\n        <h3>There is no universal winner<\/h3>\r\n        <p>\r\n          The correct arrangement depends on the project specification, SPD type,\r\n          protection modes, voltage protection level, TOV performance, RCD\r\n          coordination, lightning-current duty and the manufacturer-approved\r\n          application.\r\n        <\/p>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         N-PE\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"npe-protection\">\r\n      <h2><span class=\"ez-toc-section\" id=\"does-a-tn-s-system-need-n-pe-surge-protection\"><\/span>Does a TN-S System Need N-PE Surge Protection?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <p>\r\n        Where neutral is present, the selected SPD assembly normally requires a\r\n        clearly defined neutral-related surge protection arrangement. Depending\r\n        on the circuit, this may be part of a 4+0 \/ CT1 or 3+1 \/ CT2 design.\r\n      <\/p>\r\n\r\n      <p>\r\n        In a CT1 device, N may have a protection path toward PE. In a CT2 device,\r\n        the phase protection normally operates from L to N, with a separate N-PE\r\n        switching path.\r\n        <sup class=\"ly-tns-ref\"><a href=\"#ref-4\">[4]<\/a><\/sup>\r\n      <\/p>\r\n\r\n      <div class=\"ly-tns-callout is-red\">\r\n        <h3>N-PE surge protection is not a permanent N-PE connection<\/h3>\r\n        <p>\r\n          The SPD protection element is designed to respond under defined\r\n          overvoltage conditions. It does not justify installing a permanent\r\n          neutral-to-earth bridge in a downstream TN-S board.\r\n        <\/p>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         SELECTION PROCESS\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"selection-process\">\r\n      <h2><span class=\"ez-toc-section\" id=\"tn-s-system-spd-selection-process\"><\/span>TN-S System SPD Selection Process<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <ul class=\"ly-tns-check-list\">\r\n        <li>\r\n          <strong>Confirm the earthing system.<\/strong>\r\n          Verify that the protection point is genuinely TN-S and not TN-C-S\r\n          before or after an uncertain PEN separation point.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Confirm the conductor arrangement.<\/strong>\r\n          Check whether neutral is present at the SPD location.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Select Type 1, Type 2 or Type 1+2.<\/strong>\r\n          Base this on lightning exposure, external lightning protection,\r\n          incoming supply and project risk\u2014not only the earthing system.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Confirm CT1 or CT2.<\/strong>\r\n          Review the internal circuit diagram and protection-mode table.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Check voltage and discharge ratings.<\/strong>\r\n          Confirm Uc, Up, In, Imax, Iimp and I<sub>total<\/sub> where applicable.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Check short-circuit coordination.<\/strong>\r\n          Verify Isccr, prospective short-circuit current and permitted backup protection.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Check the installation position.<\/strong>\r\n          Confirm conductor lengths, RCD coordination, PE connection and panel layout.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Check the exact certificate scope.<\/strong>\r\n          Ensure the ordered model, voltage and configuration are covered.\r\n        <\/li>\r\n      <\/ul>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         PARAMETERS\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"parameters\">\r\n      <h2><span class=\"ez-toc-section\" id=\"parameters-to-confirm-before-ordering\"><\/span>Parameters to Confirm Before Ordering<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <div class=\"ly-tns-table-wrap\">\r\n        <table class=\"ly-tns-table\">\r\n          <thead>\r\n            <tr>\r\n              <th>Parameter<\/th>\r\n              <th>Why It Matters<\/th>\r\n              <th>Buyer Question<\/th>\r\n            <\/tr>\r\n          <\/thead>\r\n\r\n          <tbody>\r\n            <tr>\r\n              <td><strong>Uo \/ Un<\/strong>System voltage<\/td>\r\n              <td>Defines the normal phase-neutral and phase-phase voltage.<\/td>\r\n              <td>Is the system 230\/400 V, 240\/415 V or another voltage?<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Uc<\/strong>Maximum continuous voltage<\/td>\r\n              <td>Must suit the continuous voltage and expected system conditions.<\/td>\r\n              <td>Is the Uc approved for the exact TN-S system and market?<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Up<\/strong>Voltage protection level<\/td>\r\n              <td>Indicates the limiting performance under the defined test condition.<\/td>\r\n              <td>What are the relevant L-N, L-PE and N-PE protection levels?<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>In \/ Imax<\/strong>Type 2 discharge ratings<\/td>\r\n              <td>Describe nominal and maximum impulse-current performance.<\/td>\r\n              <td>Are the stated ratings per mode, per pole or for the assembly?<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Iimp<\/strong>Type 1 impulse current<\/td>\r\n              <td>Required where lightning-current duty is specified.<\/td>\r\n              <td>What is Iimp per mode and for the complete multipole assembly?<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>I<sub>total<\/sub><\/strong>Total discharge current<\/td>\r\n              <td>Important for multipole Type 1 devices and N-PE discharge paths.<\/td>\r\n              <td>Can the N-PE path handle the required total current?<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Isccr \/ Isc<\/strong>Short-circuit capability<\/td>\r\n              <td>Must coordinate with the available fault current at the panel.<\/td>\r\n              <td>What backup protection is required at the stated fault level?<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>CT1 \/ CT2<\/strong>Protection circuit<\/td>\r\n              <td>Defines the internal protection paths.<\/td>\r\n              <td>Can the supplier provide the internal circuit diagram?<\/td>\r\n            <\/tr>\r\n\r\n            <tr>\r\n              <td><strong>Remote contact<\/strong>Status signalling<\/td>\r\n              <td>Allows monitoring through PLC, BMS or alarm systems.<\/td>\r\n              <td>What are the NO\/NC logic and contact ratings?<\/td>\r\n            <\/tr>\r\n          <\/tbody>\r\n        <\/table>\r\n      <\/div>\r\n\r\n      <p>\r\n        IEC 61643-11 covers requirements and test methods for SPDs connected to\r\n        AC low-voltage power systems. Installation and selection must also follow\r\n        the applicable electrical installation requirements.\r\n        <sup class=\"ly-tns-ref\"><a href=\"#ref-1\">[1]<\/a><\/sup>\r\n        <sup class=\"ly-tns-ref\"><a href=\"#ref-2\">[2]<\/a><\/sup>\r\n      <\/p>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         RCD AND BACKUP\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"rcd-backup\">\r\n      <h2><span class=\"ez-toc-section\" id=\"rcd-position-and-spd-backup-protection\"><\/span>RCD Position and SPD Backup Protection<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <p>\r\n        RCD coordination cannot be decided from the labels \u201cCT1\u201d or \u201cCT2\u201d alone.\r\n        Check the SPD\u2019s TOV behaviour, N-PE technology, permitted installation\r\n        position and the exact manufacturer wiring instructions.\r\n      <\/p>\r\n\r\n      <p>\r\n        Some products have specific requirements for installation upstream or\r\n        downstream of residual-current protection. The final position must also\r\n        comply with the local installation rules and project design.\r\n        <sup class=\"ly-tns-ref\"><a href=\"#ref-4\">[4]<\/a><\/sup>\r\n      <\/p>\r\n\r\n      <div class=\"ly-tns-callout is-orange\">\r\n        <h3>Do not specify a universal backup breaker<\/h3>\r\n        <p>\r\n          The backup fuse or circuit breaker must be selected from the SPD\r\n          datasheet after checking the maximum permitted backup protection,\r\n          conductor size, prospective short-circuit current and selectivity.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <ul class=\"ly-tns-check-list\">\r\n        <li>Confirm the manufacturer\u2019s maximum permitted backup protection.<\/li>\r\n        <li>Check the prospective short-circuit current at the installation point.<\/li>\r\n        <li>Confirm Isccr or the stated short-circuit coordination arrangement.<\/li>\r\n        <li>Check selectivity with upstream protective devices.<\/li>\r\n        <li>Verify the required means of isolation and maintenance access.<\/li>\r\n      <\/ul>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         ERRORS\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"wiring-errors\">\r\n      <h2><span class=\"ez-toc-section\" id=\"common-tn-s-spd-wiring-and-selection-errors\"><\/span>Common TN-S SPD Wiring and Selection Errors<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <ul class=\"ly-tns-error-list\">\r\n        <li>\r\n          <strong>Choosing 3P only because the supply is three-phase.<\/strong>\r\n          A TN-S panel containing neutral loads may require a neutral-related\r\n          protection path.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Treating 4P and 3P+N as identical.<\/strong>\r\n          Similar module counts can contain different protection circuits.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Describing L-PE paths as a conventional 3+1 circuit.<\/strong>\r\n          A conventional CT2 arrangement normally uses L-N paths plus N-PE.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Reconnecting N and PE downstream.<\/strong>\r\n          Neutral and protective earth must remain separate in the TN-S installation.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Using long SPD conductors.<\/strong>\r\n          Added inductance increases the effective voltage seen by the protected equipment.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Using a generic backup-device rating.<\/strong>\r\n          Backup protection must match the exact SPD and panel fault level.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Selecting Type 1 or Type 2 only from the earthing system.<\/strong>\r\n          The SPD type depends on lightning exposure, supply and installation level.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Checking only Imax.<\/strong>\r\n          Uc, Up, In, Iimp, I<sub>total<\/sub>, Isccr and protection modes also matter.\r\n        <\/li>\r\n\r\n        <li>\r\n          <strong>Approving a certificate without checking the model scope.<\/strong>\r\n          Confirm the exact voltage and configuration listed in the certificate.\r\n        <\/li>\r\n      <\/ul>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         OEM CHECKLIST\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"oem-checklist\">\r\n      <h2><span class=\"ez-toc-section\" id=\"tn-s-spd-oem-and-bulk-ordering-checklist\"><\/span>TN-S SPD OEM and Bulk Ordering Checklist<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <p class=\"ly-tns-lead\">\r\n        Send complete system and project information before requesting a final\r\n        model, sample or bulk-order price.\r\n      <\/p>\r\n\r\n      <figure class=\"ly-tns-figure\">\r\n        <img loading=\"lazy\"\r\n          src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/tn-s-spd-oem-ordering-checklist.webp\"\r\n          alt=\"TN-S system SPD selection and OEM ordering checklist for panel builders\"\r\n          width=\"1600\"\r\n          height=\"900\"\r\n          loading=\"lazy\"\r\n          decoding=\"async\"\r\n        >\r\n        <figcaption>\r\n          <strong>TN-S SPD OEM ordering checklist:<\/strong>\r\n          confirm the electrical system, internal circuit, installation conditions,\r\n          certificate scope and private-label requirements.\r\n        <\/figcaption>\r\n      <\/figure>\r\n\r\n      <div class=\"ly-tns-card-grid\">\r\n        <div class=\"ly-tns-card\">\r\n          <span class=\"ly-tns-card-label\">System<\/span>\r\n          <h3>Electrical Information<\/h3>\r\n          <p>\r\n            TN-S confirmation, conductor arrangement, Uo\/Un, frequency,\r\n            installation point and prospective short-circuit current.\r\n          <\/p>\r\n        <\/div>\r\n\r\n        <div class=\"ly-tns-card\">\r\n          <span class=\"ly-tns-card-label\">Protection<\/span>\r\n          <h3>SPD Configuration<\/h3>\r\n          <p>\r\n            Type 1, Type 2 or Type 1+2; CT1 or CT2; Uc, Up, In, Imax,\r\n            Iimp, I<sub>total<\/sub> and backup protection.\r\n          <\/p>\r\n        <\/div>\r\n\r\n        <div class=\"ly-tns-card\">\r\n          <span class=\"ly-tns-card-label\">OEM<\/span>\r\n          <h3>Commercial Requirements<\/h3>\r\n          <p>\r\n            Exact model, quantity, sample approval, logo, label, packaging,\r\n            certificate scope and replacement-module requirement.\r\n          <\/p>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <div class=\"ly-tns-rfq\">\r\n        <div class=\"ly-tns-rfq-head\">\r\n          <h3>Copy-Ready TN-S SPD RFQ Template<\/h3>\r\n          <p>Replace the bracketed information before sending it to the supplier.<\/p>\r\n        <\/div>\r\n\r\n        <pre>Application: [Main distribution board \/ sub-distribution board \/ control panel]\r\nEarthing system: TN-S\r\nSupply conductors: [L1 \/ L2 \/ L3 \/ N \/ PE]\r\nSystem voltage: [___ V phase-to-phase \/ ___ V phase-to-neutral]\r\nFrequency: [50 \/ 60 Hz]\r\nNeutral available at SPD point: [Yes \/ No]\r\nProspective short-circuit current: [___ kA]\r\n\r\nRequired SPD type: [Type 1 \/ Type 2 \/ Type 1+2]\r\nRequired protection circuit: [CT1 \/ 4+0] or [CT2 \/ 3+1]\r\nRequired Uc: [___ V AC]\r\nRequired Up: [___ kV]\r\nRequired In \/ Imax: [___ kA \/ ___ kA]\r\nRequired Iimp \/ Itotal: [___ kA \/ ___ kA]\r\nBackup protection: [Please recommend from the exact datasheet]\r\n\r\nRCD position or project requirement: [___]\r\nRemote indication: [Required \/ Not required]\r\nPluggable module: [Required \/ Optional]\r\nCertificate required: [IEC \/ EN \/ T\u00dcV \/ CB \/ CE \/ project-specific]\r\nOEM logo and label: [Yes \/ No]\r\nPackaging language: [___]\r\nEstimated quantity: [___ units]\r\nRequired delivery date: [___]\r\n\r\nPlease provide:\r\n1. Exact model number\r\n2. Internal protection circuit\r\n3. Wiring diagram\r\n4. Datasheet\r\n5. Backup protection requirement\r\n6. Certificate and model scope\r\n7. Product and label drawing\r\n8. Sample and bulk-order lead time<\/pre>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         CTA\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-cta\">\r\n      <div class=\"ly-tns-cta-grid\">\r\n        <div>\r\n          <h2><span class=\"ez-toc-section\" id=\"need-to-confirm-a-tn-s-spd-before-ordering\"><\/span>Need to confirm a TN-S SPD before ordering?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n          <p>\r\n            Send LEEYEE your single-line diagram, system voltage, required SPD type,\r\n            short-circuit level and preferred protection circuit. We can help confirm\r\n            the model, wiring logic, backup protection and OEM requirements.\r\n          <\/p>\r\n        <\/div>\r\n\r\n        <button\r\n          type=\"button\"\r\n          class=\"ly-tns-btn leeyee-site-popup-btn\"\r\n          aria-label=\"Request a TN-S SPD recommendation\"\r\n        >\r\n          <span class=\"w-btn-label\">\r\n            Request TN-S SPD Recommendation\r\n          <\/span>\r\n        <\/button>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         RELATED\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\">\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\r\n      <div class=\"ly-tns-related\">\r\n        <a\r\n          href=\"https:\/\/www.cnspd.com\/three-phase-spd-wiring-diagram\/\"\r\n          target=\"_blank\"\r\n          rel=\"noopener\"\r\n        >\r\n          Three-Phase SPD Wiring Diagram Guide\r\n        <\/a>\r\n\r\n        <a\r\n          href=\"https:\/\/www.cnspd.com\/3pn-spd-vs-4p-spd\/\"\r\n          target=\"_blank\"\r\n          rel=\"noopener\"\r\n        >\r\n          3P+N SPD vs 4P SPD\r\n        <\/a>\r\n\r\n        <a\r\n          href=\"https:\/\/www.cnspd.com\/tt-system-spd\/\"\r\n          target=\"_blank\"\r\n          rel=\"noopener\"\r\n        >\r\n          TT System SPD and 3+1 Wiring Guide\r\n        <\/a>\r\n\r\n        <a\r\n          href=\"https:\/\/www.cnspd.com\/spd-uc-selection-guide\/\"\r\n          target=\"_blank\"\r\n          rel=\"noopener\"\r\n        >\r\n          SPD Uc Selection Guide\r\n        <\/a>\r\n\r\n        <a\r\n          href=\"https:\/\/www.cnspd.com\/spd-up-voltage-protection-level\/\"\r\n          target=\"_blank\"\r\n          rel=\"noopener\"\r\n        >\r\n          SPD Up Voltage Protection Level\r\n        <\/a>\r\n\r\n        <a\r\n          href=\"https:\/\/www.cnspd.com\/spd-selection-guide\/\"\r\n          target=\"_blank\"\r\n          rel=\"noopener\"\r\n        >\r\n          Complete SPD Selection Guide\r\n        <\/a>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         FAQ\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\" id=\"faq\">\r\n      <h2><span class=\"ez-toc-section\" id=\"tn-s-system-spd-wiring-faq\"><\/span>TN-S System SPD Wiring FAQ<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <div class=\"ly-tns-faq\">\r\n        <details>\r\n          <summary>Can a 3P SPD be used in a TN-S system?<\/summary>\r\n          <div class=\"ly-tns-faq-answer\">\r\n            <p>\r\n              It may be used where the protected circuit has no neutral conductor\r\n              or where the approved project design specifically requires three-pole\r\n              protection. It should not be selected automatically for a five-conductor\r\n              TN-S panel.\r\n            <\/p>\r\n          <\/div>\r\n        <\/details>\r\n\r\n        <details>\r\n          <summary>Is a 4P SPD the same as a 3P+N SPD?<\/summary>\r\n          <div class=\"ly-tns-faq-answer\">\r\n            <p>\r\n              Not necessarily. A 4P device often uses 4+0 \/ CT1, while a 3P+N\r\n              device often uses 3+1 \/ CT2. Check the internal circuit diagram.\r\n            <\/p>\r\n          <\/div>\r\n        <\/details>\r\n\r\n        <details>\r\n          <summary>Can both 4+0 and 3+1 be used in TN-S?<\/summary>\r\n          <div class=\"ly-tns-faq-answer\">\r\n            <p>\r\n              Yes, manufacturer documentation shows that both arrangements may be\r\n              available for TN-S systems. The final choice must match the project,\r\n              local rules and the approved application of the exact SPD.\r\n            <\/p>\r\n          <\/div>\r\n        <\/details>\r\n\r\n        <details>\r\n          <summary>Should the SPD be installed before or after the RCD?<\/summary>\r\n          <div class=\"ly-tns-faq-answer\">\r\n            <p>\r\n              There is no universal answer for every SPD. Check the product\u2019s TOV\r\n              behaviour, N-PE technology, permitted position, local installation\r\n              rules and manufacturer instructions.\r\n            <\/p>\r\n          <\/div>\r\n        <\/details>\r\n\r\n        <details>\r\n          <summary>What backup breaker should be used?<\/summary>\r\n          <div class=\"ly-tns-faq-answer\">\r\n            <p>\r\n              Use the fuse or circuit breaker specified for the exact SPD after\r\n              checking the short-circuit current, Isccr, conductor size and\r\n              coordination with upstream protection.\r\n            <\/p>\r\n          <\/div>\r\n        <\/details>\r\n\r\n        <details>\r\n          <summary>What should an OEM buyer request before approval?<\/summary>\r\n          <div class=\"ly-tns-faq-answer\">\r\n            <p>\r\n              Request the internal circuit diagram, wiring diagram, datasheet,\r\n              backup-protection requirement, certificate scope, product drawing\r\n              and label drawing.\r\n            <\/p>\r\n          <\/div>\r\n        <\/details>\r\n      <\/div>\r\n    <\/section>\r\n\r\n    <!-- =====================================================\r\n         REFERENCES\r\n         ===================================================== -->\r\n    <section class=\"ly-tns-section\">\r\n      <h2><span class=\"ez-toc-section\" id=\"technical-references\"><\/span>Technical References<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n      <div class=\"ly-tns-references\">\r\n        <ol>\r\n          <li id=\"ref-1\">\r\n            IEC 60364-5-53: Low-voltage electrical installations \u2014 Selection and\r\n            erection of electrical equipment.\r\n            <a\r\n              href=\"https:\/\/webstore.iec.ch\/en\/publication\/104394\"\r\n              target=\"_blank\"\r\n              rel=\"noopener nofollow\"\r\n            >Official IEC publication<\/a>.\r\n          <\/li>\r\n\r\n          <li id=\"ref-2\">\r\n            IEC 61643-11: Low-voltage surge protective devices connected to AC\r\n            low-voltage power systems \u2014 Requirements and test methods.\r\n            <a\r\n              href=\"https:\/\/webstore.iec.ch\/en\/publication\/65314\"\r\n              target=\"_blank\"\r\n              rel=\"noopener nofollow\"\r\n            >Official IEC publication<\/a>.\r\n          <\/li>\r\n\r\n          <li id=\"ref-3\">\r\n            Legrand, Modular Surge Protective Devices, technical sheet F04648EN-00.\r\n            Includes CT1 \/ X+0 and CT2 \/ X+1 protection modes and applicable\r\n            earthing systems.\r\n            <a\r\n              href=\"https:\/\/assets.legrand.com\/pim\/NP-FT-GT\/F04648EN-00.pdf\"\r\n              target=\"_blank\"\r\n              rel=\"noopener nofollow\"\r\n            >Official PDF<\/a>.\r\n          <\/li>\r\n\r\n          <li id=\"ref-4\">\r\n            Legrand, Surge Protective Devices Technical Guide. Explains CT1 and\r\n            CT2 circuits, N-PE components, TOV behaviour and RCD coordination.\r\n            <a\r\n              href=\"https:\/\/assets.legrand.com\/pim\/NP-FT-GT\/EXB20026_TG_Surge_Protective_Devices_EN.pdf\"\r\n              target=\"_blank\"\r\n              rel=\"noopener nofollow\"\r\n            >Official PDF<\/a>.\r\n          <\/li>\r\n\r\n          <li id=\"ref-5\">\r\n            ABB Furse, ESP 240CDT2 installation instructions for three-phase\r\n            TN-S, TN-C-S and TT supplies.\r\n            <a\r\n              href=\"https:\/\/library.e.abb.com\/public\/51773fd8b59d41fb8d61ab96db3d53af\/ABB-ESP-240CDT2-Surge-Protection-Series-Instructions_231121.pdf\"\r\n              target=\"_blank\"\r\n              rel=\"noopener nofollow\"\r\n            >Official PDF<\/a>.\r\n          <\/li>\r\n\r\n          <li id=\"ref-6\">\r\n            Phoenix Contact, selection guide for lightning and surge protection\r\n            in industrial buildings, including five-conductor TN-S systems.\r\n            <a\r\n              href=\"https:\/\/assets.phoenixcontact.com\/file\/58692c24-b52d-477f-991b-873f57813f1d\/media\/original?1351957_EN_UESS_Auswahlhilfe_LoRes.pdf=\"\r\n              target=\"_blank\"\r\n              rel=\"noopener nofollow\"\r\n            >Official PDF<\/a>.\r\n          <\/li>\r\n\r\n          <li id=\"ref-7\">\r\n            DEHN, Surge Protection in Low-Voltage Switchgear Assemblies.\r\n            Includes modular SPD solutions for TN-S installations.\r\n            <a\r\n              href=\"https:\/\/www.dehn-international.com\/sites\/default\/files\/media\/files\/surge-protection-low-voltage-switchgear-assemblies-wpx004-e.pdf\"\r\n              target=\"_blank\"\r\n              rel=\"noopener nofollow\"\r\n            >Official PDF<\/a>.\r\n          <\/li>\r\n        <\/ol>\r\n      <\/div>\r\n    <\/section>\r\n\r\n  <\/article>\r\n<\/div>\r\n\r\n<script>\r\ndocument.addEventListener('DOMContentLoaded', function () {\r\n  var popupButtons = document.querySelectorAll('.leeyee-site-popup-btn');\r\n\r\n  popupButtons.forEach(function (button) {\r\n    if (button.getAttribute('data-leeyee-popup-bound') === 'true') {\r\n      return;\r\n    }\r\n\r\n    button.setAttribute('data-leeyee-popup-bound', 'true');\r\n\r\n    button.addEventListener('click', function (event) {\r\n      event.preventDefault();\r\n\r\n      var realPopupTrigger = document.querySelector(\r\n        '.w-popup.ush_popup_1 .w-popup-trigger'\r\n      );\r\n\r\n      if (realPopupTrigger) {\r\n        realPopupTrigger.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>Sistem TN-S \u00b7 Distribusi Tiga Fase \u00b7 Pemilihan OEM Sekilas Pengkabelan SPD TN-S Dalam sistem TN-S tiga fase, perangkat pelindung lonjakan arus dihubungkan secara paralel dengan L1, L2, L3, N, dan PE sesuai dengan sirkuit internal yang disetujui dari SPD yang dipilih. Netral dan arde pelindung tetap terpisah selama operasi normal. Jawaban Singkat:&#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-30017","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 v28.3 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>TN-S System SPD Wiring: 3P, 4P or 3P+N? | LEEYEE<\/title>\n<meta name=\"description\" content=\"See how to wire an SPD in a three-phase TN-S system. Compare 3P, 4P, 3P+N, 4+0 and 3+1, and confirm N-PE protection before ordering.\" \/>\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\/id\/tn-s-system-spd-wiring\/\" \/>\n<meta property=\"og:locale\" content=\"id_ID\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"TN-S System SPD Wiring: 3P, 4P or 3P+N? | LEEYEE\" \/>\n<meta property=\"og:description\" content=\"See how to wire an SPD in a three-phase TN-S system. Compare 3P, 4P, 3P+N, 4+0 and 3+1, and confirm N-PE protection before ordering.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.cnspd.com\/id\/tn-s-system-spd-wiring\/\" \/>\n<meta property=\"og:site_name\" content=\"Surge Protector, Surge Arrestor, Isolating Switch - LEEYEE\" \/>\n<meta property=\"article:published_time\" content=\"2026-07-14T04:57:20+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-07-14T06:32:37+00:00\" \/>\n<meta name=\"author\" content=\"Devin Ling\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Ditulis oleh\" \/>\n\t<meta name=\"twitter:data1\" content=\"Devin Ling\" \/>\n\t<meta name=\"twitter:label2\" content=\"Estimasi waktu membaca\" \/>\n\t<meta name=\"twitter:data2\" content=\"12 menit\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/tn-s-system-spd-wiring\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/tn-s-system-spd-wiring\\\/\"},\"author\":{\"name\":\"Devin Ling\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#\\\/schema\\\/person\\\/f49dbafe62c5b47100ad2d9f88af92d3\"},\"headline\":\"TN-S System SPD Wiring Guide: 3P, 4P and 3P+N Selection\",\"datePublished\":\"2026-07-14T04:57:20+00:00\",\"dateModified\":\"2026-07-14T06:32:37+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/tn-s-system-spd-wiring\\\/\"},\"wordCount\":2509,\"articleSection\":[\"News\",\"Surge Protection\",\"Technical Guides\"],\"inLanguage\":\"id\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/tn-s-system-spd-wiring\\\/\",\"url\":\"https:\\\/\\\/www.cnspd.com\\\/tn-s-system-spd-wiring\\\/\",\"name\":\"TN-S System SPD Wiring: 3P, 4P or 3P+N? | LEEYEE\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#website\"},\"datePublished\":\"2026-07-14T04:57:20+00:00\",\"dateModified\":\"2026-07-14T06:32:37+00:00\",\"author\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#\\\/schema\\\/person\\\/f49dbafe62c5b47100ad2d9f88af92d3\"},\"description\":\"See how to wire an SPD in a three-phase TN-S system. Compare 3P, 4P, 3P+N, 4+0 and 3+1, and confirm N-PE protection before ordering.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/tn-s-system-spd-wiring\\\/#breadcrumb\"},\"inLanguage\":\"id\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.cnspd.com\\\/tn-s-system-spd-wiring\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/tn-s-system-spd-wiring\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.cnspd.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"TN-S System SPD Wiring Guide: 3P, 4P and 3P+N Selection\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#website\",\"url\":\"https:\\\/\\\/www.cnspd.com\\\/\",\"name\":\"Surge Protector, Surge Arrestor, Isolating Switch - LEEYEE\",\"description\":\"Surge Protector, Surge Arrestor, Isolating Switch - LEEYEE\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.cnspd.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"id\"},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#\\\/schema\\\/person\\\/f49dbafe62c5b47100ad2d9f88af92d3\",\"name\":\"Devin Ling\",\"sameAs\":[\"https:\\\/\\\/cnspd.com\\\/\"],\"url\":\"https:\\\/\\\/www.cnspd.com\\\/id\\\/author\\\/devin\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Pengkabelan SPD Sistem TN-S: 3P, 4P atau 3P+N? | LEEYEE","description":"Lihat cara menghubungkan SPD dalam sistem TN-S tiga fase. Bandingkan 3P, 4P, 3P+N, 4+0 dan 3+1, dan pastikan perlindungan N-PE sebelum melakukan pemesanan.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.cnspd.com\/id\/tn-s-system-spd-wiring\/","og_locale":"id_ID","og_type":"article","og_title":"TN-S System SPD Wiring: 3P, 4P or 3P+N? | LEEYEE","og_description":"See how to wire an SPD in a three-phase TN-S system. Compare 3P, 4P, 3P+N, 4+0 and 3+1, and confirm N-PE protection before ordering.","og_url":"https:\/\/www.cnspd.com\/id\/tn-s-system-spd-wiring\/","og_site_name":"Surge Protector, Surge Arrestor, Isolating Switch - LEEYEE","article_published_time":"2026-07-14T04:57:20+00:00","article_modified_time":"2026-07-14T06:32:37+00:00","author":"Devin Ling","twitter_card":"summary_large_image","twitter_misc":{"Ditulis oleh":"Devin Ling","Estimasi waktu membaca":"12 menit"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.cnspd.com\/tn-s-system-spd-wiring\/#article","isPartOf":{"@id":"https:\/\/www.cnspd.com\/tn-s-system-spd-wiring\/"},"author":{"name":"Devin Ling","@id":"https:\/\/www.cnspd.com\/#\/schema\/person\/f49dbafe62c5b47100ad2d9f88af92d3"},"headline":"TN-S System SPD Wiring Guide: 3P, 4P and 3P+N Selection","datePublished":"2026-07-14T04:57:20+00:00","dateModified":"2026-07-14T06:32:37+00:00","mainEntityOfPage":{"@id":"https:\/\/www.cnspd.com\/tn-s-system-spd-wiring\/"},"wordCount":2509,"articleSection":["News","Surge Protection","Technical Guides"],"inLanguage":"id"},{"@type":"WebPage","@id":"https:\/\/www.cnspd.com\/tn-s-system-spd-wiring\/","url":"https:\/\/www.cnspd.com\/tn-s-system-spd-wiring\/","name":"Pengkabelan SPD Sistem TN-S: 3P, 4P atau 3P+N? | LEEYEE","isPartOf":{"@id":"https:\/\/www.cnspd.com\/#website"},"datePublished":"2026-07-14T04:57:20+00:00","dateModified":"2026-07-14T06:32:37+00:00","author":{"@id":"https:\/\/www.cnspd.com\/#\/schema\/person\/f49dbafe62c5b47100ad2d9f88af92d3"},"description":"Lihat cara menghubungkan SPD dalam sistem TN-S tiga fase. Bandingkan 3P, 4P, 3P+N, 4+0 dan 3+1, dan pastikan perlindungan N-PE sebelum melakukan pemesanan.","breadcrumb":{"@id":"https:\/\/www.cnspd.com\/tn-s-system-spd-wiring\/#breadcrumb"},"inLanguage":"id","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.cnspd.com\/tn-s-system-spd-wiring\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.cnspd.com\/tn-s-system-spd-wiring\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.cnspd.com\/"},{"@type":"ListItem","position":2,"name":"TN-S System SPD Wiring Guide: 3P, 4P and 3P+N Selection"}]},{"@type":"WebSite","@id":"https:\/\/www.cnspd.com\/#website","url":"https:\/\/www.cnspd.com\/","name":"Penjaga Lonjakan, Penangkap Lonjakan, Saklar Isolasi - LEEYEE","description":"Penjaga Lonjakan, Penangkap Lonjakan, Saklar Isolasi - LEEYEE","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.cnspd.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"id"},{"@type":"Person","@id":"https:\/\/www.cnspd.com\/#\/schema\/person\/f49dbafe62c5b47100ad2d9f88af92d3","name":"Devin Ling","sameAs":["https:\/\/cnspd.com\/"],"url":"https:\/\/www.cnspd.com\/id\/author\/devin\/"}]}},"_links":{"self":[{"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/posts\/30017","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/users\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/comments?post=30017"}],"version-history":[{"count":3,"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/posts\/30017\/revisions"}],"predecessor-version":[{"id":30022,"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/posts\/30017\/revisions\/30022"}],"wp:attachment":[{"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/media?parent=30017"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/categories?post=30017"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cnspd.com\/id\/wp-json\/wp\/v2\/tags?post=30017"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}