{"id":30070,"date":"2026-07-15T13:24:52","date_gmt":"2026-07-15T05:24:52","guid":{"rendered":"https:\/\/www.cnspd.com\/?p=30070"},"modified":"2026-07-15T15:14:52","modified_gmt":"2026-07-15T07:14:52","slug":"spd-cable-length-how-panel-builders-apply-the-0-5-m-rule","status":"publish","type":"post","link":"https:\/\/www.cnspd.com\/pt\/spd-cable-length-0-5m\/","title":{"rendered":"SPD Cable Length: How Panel Builders Apply the 0.5 m Rule"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"30070\" class=\"elementor elementor-30070\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-11f0041 e-flex e-con-boxed e-con e-parent\" data-id=\"11f0041\" 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-2ac2584 elementor-widget elementor-widget-html\" data-id=\"2ac2584\" 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  .ly-spd05,\r\n  .ly-spd05 * {\r\n    box-sizing: border-box;\r\n  }\r\n\r\n  .ly-spd05 {\r\n    --ly-blue: #004898;\r\n    --ly-blue-dark: #00366f;\r\n    --ly-blue-soft: #edf5ff;\r\n    --ly-navy: #142f4f;\r\n    --ly-green: #16845b;\r\n    --ly-green-soft: #edf8f3;\r\n    --ly-orange: #a95500;\r\n    --ly-orange-soft: #fff7e8;\r\n    --ly-red: #b42318;\r\n    --ly-red-soft: #fff3f2;\r\n    --ly-text: #1d2935;\r\n    --ly-muted: #5d6975;\r\n    --ly-line: #dce4ec;\r\n    --ly-bg: #f6f8fb;\r\n    --ly-white: #ffffff;\r\n    --ly-radius: 14px;\r\n    --ly-shadow: 0 10px 28px rgba(15, 38, 64, 0.07);\r\n\r\n    width: 100%;\r\n    max-width: 1160px;\r\n    margin: 0 auto;\r\n    color: var(--ly-text);\r\n    font-family: Arial, Helvetica, sans-serif;\r\n    font-size: 17px;\r\n    line-height: 1.72;\r\n    overflow-wrap: anywhere;\r\n  }\r\n\r\n  .ly-spd05 p {\r\n    max-width: 84ch;\r\n    margin: 0 0 18px;\r\n  }\r\n\r\n  .ly-spd05 ul,\r\n  .ly-spd05 ol {\r\n    max-width: 86ch;\r\n    margin: 0 0 22px;\r\n    padding-left: 24px;\r\n  }\r\n\r\n  .ly-spd05 li {\r\n    margin-bottom: 9px;\r\n  }\r\n\r\n  .ly-spd05 strong {\r\n    color: #152333;\r\n  }\r\n\r\n  .ly-spd05 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-spd05 a:hover,\r\n  .ly-spd05 a:focus {\r\n    color: var(--ly-blue-dark);\r\n  }\r\n\r\n  .ly-spd05 h2,\r\n  .ly-spd05 h3 {\r\n    color: #14263a;\r\n    line-height: 1.28;\r\n    scroll-margin-top: 110px;\r\n  }\r\n\r\n  .ly-spd05 h2 {\r\n    margin: 60px 0 22px;\r\n    padding-bottom: 12px;\r\n    border-bottom: 2px solid var(--ly-blue);\r\n    font-size: 31px;\r\n    letter-spacing: -0.35px;\r\n  }\r\n\r\n  .ly-spd05 h3 {\r\n    margin: 32px 0 14px;\r\n    font-size: 22px;\r\n  }\r\n\r\n  .ly-spd05-intro {\r\n    padding: 3px 0 8px;\r\n  }\r\n\r\n  .ly-spd05-eyebrow {\r\n    display: inline-block;\r\n    margin-bottom: 14px;\r\n    color: var(--ly-blue);\r\n    font-size: 13px;\r\n    font-weight: 800;\r\n    letter-spacing: 1.05px;\r\n    text-transform: uppercase;\r\n  }\r\n\r\n  .ly-spd05-lead {\r\n    max-width: 940px;\r\n    margin: 0;\r\n    color: #2a3948;\r\n    font-size: 21px;\r\n    line-height: 1.62;\r\n  }\r\n\r\n  .ly-spd05-answer {\r\n    margin: 30px 0;\r\n    padding: 26px 28px;\r\n    border: 1px solid #b9d3ef;\r\n    border-left: 6px solid var(--ly-blue);\r\n    border-radius: var(--ly-radius);\r\n    background: var(--ly-blue-soft);\r\n    box-shadow: var(--ly-shadow);\r\n  }\r\n\r\n  .ly-spd05-answer-title {\r\n    display: block;\r\n    margin-bottom: 10px;\r\n    color: var(--ly-blue-dark);\r\n    font-size: 20px;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-answer p:last-child {\r\n    margin-bottom: 0;\r\n  }\r\n\r\n  .ly-spd05-keyline {\r\n    margin: 24px 0;\r\n    padding: 18px 22px;\r\n    border-radius: 10px;\r\n    background: var(--ly-navy);\r\n    color: #ffffff;\r\n    font-size: 20px;\r\n    font-weight: 700;\r\n    line-height: 1.55;\r\n  }\r\n\r\n  .ly-spd05-keyline strong {\r\n    color: #ffffff;\r\n  }\r\n\r\n  .ly-spd05-toc {\r\n    margin: 28px 0 42px;\r\n    padding: 24px 26px;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: var(--ly-radius);\r\n    background: var(--ly-bg);\r\n  }\r\n\r\n  .ly-spd05-toc-title {\r\n    display: block;\r\n    margin-bottom: 14px;\r\n    color: #182a3d;\r\n    font-size: 18px;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-toc ol {\r\n    display: grid;\r\n    grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    gap: 8px 30px;\r\n    margin: 0;\r\n    padding-left: 22px;\r\n  }\r\n\r\n  .ly-spd05-toc li {\r\n    margin: 0;\r\n  }\r\n\r\n  .ly-spd05-toc a {\r\n    color: #24435f;\r\n    text-decoration: none;\r\n  }\r\n\r\n  .ly-spd05-toc a:hover,\r\n  .ly-spd05-toc a:focus {\r\n    color: var(--ly-blue);\r\n    text-decoration: underline;\r\n  }\r\n\r\n  .ly-spd05-note,\r\n  .ly-spd05-warning,\r\n  .ly-spd05-success {\r\n    margin: 24px 0;\r\n    padding: 20px 22px;\r\n    border-radius: 12px;\r\n  }\r\n\r\n  .ly-spd05-note {\r\n    border: 1px solid #bcd9df;\r\n    background: #edf9fb;\r\n  }\r\n\r\n  .ly-spd05-warning {\r\n    border: 1px solid #efca8e;\r\n    background: var(--ly-orange-soft);\r\n  }\r\n\r\n  .ly-spd05-success {\r\n    border: 1px solid #b8dfce;\r\n    background: var(--ly-green-soft);\r\n  }\r\n\r\n  .ly-spd05-note p:last-child,\r\n  .ly-spd05-warning p:last-child,\r\n  .ly-spd05-success p:last-child {\r\n    margin-bottom: 0;\r\n  }\r\n\r\n  .ly-spd05-label {\r\n    display: block;\r\n    margin-bottom: 7px;\r\n    font-size: 15px;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-note .ly-spd05-label {\r\n    color: #145d6b;\r\n  }\r\n\r\n  .ly-spd05-warning .ly-spd05-label {\r\n    color: #804200;\r\n  }\r\n\r\n  .ly-spd05-success .ly-spd05-label {\r\n    color: #116a48;\r\n  }\r\n\r\n  .ly-spd05-grid {\r\n    display: grid;\r\n    grid-template-columns: repeat(3, minmax(0, 1fr));\r\n    gap: 20px;\r\n    margin: 26px 0;\r\n  }\r\n\r\n  .ly-spd05-grid-2 {\r\n    display: grid;\r\n    grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    gap: 22px;\r\n    margin: 26px 0;\r\n  }\r\n\r\n  .ly-spd05-card {\r\n    height: 100%;\r\n    padding: 23px;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: var(--ly-radius);\r\n    background: var(--ly-white);\r\n    box-shadow: 0 8px 24px rgba(15, 38, 64, 0.05);\r\n  }\r\n\r\n  .ly-spd05-card h3 {\r\n    margin: 0 0 12px;\r\n    font-size: 20px;\r\n  }\r\n\r\n  .ly-spd05-card p:last-child,\r\n  .ly-spd05-card ul:last-child {\r\n    margin-bottom: 0;\r\n  }\r\n\r\n  .ly-spd05-card-number {\r\n    display: inline-flex;\r\n    align-items: center;\r\n    justify-content: center;\r\n    width: 34px;\r\n    height: 34px;\r\n    margin-bottom: 13px;\r\n    border-radius: 50%;\r\n    background: var(--ly-blue);\r\n    color: #ffffff;\r\n    font-size: 15px;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-definition {\r\n    margin: 24px 0;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: var(--ly-radius);\r\n    background: #ffffff;\r\n    overflow: hidden;\r\n  }\r\n\r\n  .ly-spd05-definition-row {\r\n    display: grid;\r\n    grid-template-columns: 210px minmax(0, 1fr);\r\n    border-bottom: 1px solid var(--ly-line);\r\n  }\r\n\r\n  .ly-spd05-definition-row:last-child {\r\n    border-bottom: 0;\r\n  }\r\n\r\n  .ly-spd05-definition-term,\r\n  .ly-spd05-definition-desc {\r\n    padding: 17px 19px;\r\n  }\r\n\r\n  .ly-spd05-definition-term {\r\n    background: #eef4fa;\r\n    color: #173f67;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-definition-desc {\r\n    color: #3a4855;\r\n  }\r\n\r\n  .ly-spd05-formula {\r\n    margin: 28px 0;\r\n    padding: 25px;\r\n    border: 1px solid #bfd3e8;\r\n    border-radius: var(--ly-radius);\r\n    background: linear-gradient(135deg, #f2f7fd 0%, #ffffff 100%);\r\n    text-align: center;\r\n  }\r\n\r\n  .ly-spd05-formula-main {\r\n    display: block;\r\n    margin-bottom: 10px;\r\n    color: var(--ly-blue-dark);\r\n    font-family: \"Times New Roman\", Times, serif;\r\n    font-size: 30px;\r\n    font-weight: 700;\r\n  }\r\n\r\n  .ly-spd05-formula-small {\r\n    display: block;\r\n    color: #435363;\r\n    font-size: 15px;\r\n    line-height: 1.55;\r\n  }\r\n\r\n  .ly-spd05-table-wrap {\r\n    width: 100%;\r\n    margin: 26px 0;\r\n    overflow-x: auto;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: 12px;\r\n    background: #ffffff;\r\n    -webkit-overflow-scrolling: touch;\r\n  }\r\n\r\n  .ly-spd05-table {\r\n    width: 100%;\r\n    min-width: 760px;\r\n    margin: 0;\r\n    border-collapse: collapse;\r\n  }\r\n\r\n  .ly-spd05-table th,\r\n  .ly-spd05-table td {\r\n    padding: 15px 16px;\r\n    border-right: 1px solid var(--ly-line);\r\n    border-bottom: 1px solid var(--ly-line);\r\n    text-align: left;\r\n    vertical-align: top;\r\n  }\r\n\r\n  .ly-spd05-table th:last-child,\r\n  .ly-spd05-table td:last-child {\r\n    border-right: 0;\r\n  }\r\n\r\n  .ly-spd05-table tr:last-child td {\r\n    border-bottom: 0;\r\n  }\r\n\r\n  .ly-spd05-table th {\r\n    background: #eaf2fa;\r\n    color: #163b61;\r\n    font-size: 15px;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-table td {\r\n    color: #33414e;\r\n    font-size: 15px;\r\n    line-height: 1.58;\r\n  }\r\n\r\n  .ly-spd05-table tbody tr:nth-child(even) td {\r\n    background: #fafbfd;\r\n  }\r\n\r\n  .ly-spd05-table-note {\r\n    margin: -14px 0 26px;\r\n    color: var(--ly-muted);\r\n    font-size: 13px;\r\n    line-height: 1.5;\r\n  }\r\n\r\n  .ly-spd05-figure {\r\n    width: 100%;\r\n    margin: 32px 0;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: var(--ly-radius);\r\n    background: #ffffff;\r\n    box-shadow: var(--ly-shadow);\r\n    overflow: hidden;\r\n  }\r\n\r\n  .ly-spd05-figure-link {\r\n    position: relative;\r\n    display: block;\r\n    width: 100%;\r\n    overflow: hidden;\r\n    background: #ffffff;\r\n    cursor: zoom-in;\r\n    text-decoration: none !important;\r\n  }\r\n\r\n  .ly-spd05-figure img {\r\n    display: block;\r\n    width: 100%;\r\n    height: auto;\r\n    margin: 0;\r\n    border: 0;\r\n    object-fit: contain;\r\n    transition: transform 0.25s ease;\r\n  }\r\n\r\n  .ly-spd05-figure-link:hover img {\r\n    transform: scale(1.008);\r\n  }\r\n\r\n  .ly-spd05-zoom {\r\n    position: absolute;\r\n    right: 14px;\r\n    bottom: 14px;\r\n    display: inline-flex;\r\n    align-items: center;\r\n    min-height: 34px;\r\n    padding: 7px 11px;\r\n    border-radius: 6px;\r\n    background: rgba(10, 41, 75, 0.9);\r\n    color: #ffffff;\r\n    font-size: 12px;\r\n    font-weight: 800;\r\n    line-height: 1.2;\r\n    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.18);\r\n  }\r\n\r\n  .ly-spd05-figure figcaption {\r\n    padding: 15px 18px;\r\n    border-top: 1px solid var(--ly-line);\r\n    background: #f7f9fc;\r\n    color: #536170;\r\n    font-size: 14px;\r\n    line-height: 1.55;\r\n  }\r\n\r\n  .ly-spd05-figure figcaption strong {\r\n    color: #26394d;\r\n  }\r\n\r\n  .ly-spd05-worked {\r\n    margin: 28px 0;\r\n    padding: 25px;\r\n    border: 1px solid #bad7c9;\r\n    border-radius: var(--ly-radius);\r\n    background: #f2faf6;\r\n  }\r\n\r\n  .ly-spd05-worked h3 {\r\n    margin: 0 0 16px;\r\n    color: #145f43;\r\n    font-size: 21px;\r\n  }\r\n\r\n  .ly-spd05-calculation {\r\n    display: grid;\r\n    grid-template-columns: repeat(4, minmax(0, 1fr));\r\n    gap: 12px;\r\n    margin: 20px 0;\r\n  }\r\n\r\n  .ly-spd05-calc-item {\r\n    padding: 16px 12px;\r\n    border: 1px solid #cce4d8;\r\n    border-radius: 9px;\r\n    background: #ffffff;\r\n    text-align: center;\r\n  }\r\n\r\n  .ly-spd05-calc-symbol {\r\n    display: block;\r\n    margin-bottom: 4px;\r\n    color: #176746;\r\n    font-size: 17px;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-calc-value {\r\n    display: block;\r\n    color: #273d32;\r\n    font-size: 16px;\r\n    font-weight: 700;\r\n  }\r\n\r\n  .ly-spd05-worked-result {\r\n    margin: 16px 0 0;\r\n    padding: 15px 17px;\r\n    border-radius: 8px;\r\n    background: #dff3e8;\r\n    color: #145f43;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-steps {\r\n    margin: 28px 0;\r\n    counter-reset: ly-step;\r\n  }\r\n\r\n  .ly-spd05-step {\r\n    position: relative;\r\n    margin: 0 0 18px;\r\n    padding: 22px 22px 22px 72px;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: 12px;\r\n    background: #ffffff;\r\n  }\r\n\r\n  .ly-spd05-step::before {\r\n    counter-increment: ly-step;\r\n    content: counter(ly-step);\r\n    position: absolute;\r\n    top: 21px;\r\n    left: 22px;\r\n    display: flex;\r\n    align-items: center;\r\n    justify-content: center;\r\n    width: 34px;\r\n    height: 34px;\r\n    border-radius: 50%;\r\n    background: var(--ly-blue);\r\n    color: #ffffff;\r\n    font-size: 15px;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-step h3 {\r\n    margin: 0 0 8px;\r\n    font-size: 20px;\r\n  }\r\n\r\n  .ly-spd05-step p:last-child {\r\n    margin-bottom: 0;\r\n  }\r\n\r\n  .ly-spd05-checklist {\r\n    display: grid;\r\n    grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    gap: 12px 22px;\r\n    margin: 24px 0;\r\n    padding: 24px;\r\n    border: 1px solid #bdd6ef;\r\n    border-radius: var(--ly-radius);\r\n    background: var(--ly-blue-soft);\r\n  }\r\n\r\n  .ly-spd05-check {\r\n    position: relative;\r\n    padding-left: 29px;\r\n    color: #2f4255;\r\n  }\r\n\r\n  .ly-spd05-check::before {\r\n    content: \"\u2713\";\r\n    position: absolute;\r\n    top: 0;\r\n    left: 0;\r\n    color: var(--ly-green);\r\n    font-weight: 900;\r\n  }\r\n\r\n  .ly-spd05-faq {\r\n    margin: 26px 0;\r\n  }\r\n\r\n  .ly-spd05-faq details {\r\n    margin-bottom: 12px;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: 11px;\r\n    background: #ffffff;\r\n    overflow: hidden;\r\n  }\r\n\r\n  .ly-spd05-faq summary {\r\n    position: relative;\r\n    padding: 18px 52px 18px 20px;\r\n    color: #18334f;\r\n    cursor: pointer;\r\n    list-style: none;\r\n    font-size: 17px;\r\n    font-weight: 800;\r\n  }\r\n\r\n  .ly-spd05-faq summary::-webkit-details-marker {\r\n    display: none;\r\n  }\r\n\r\n  .ly-spd05-faq summary::after {\r\n    content: \"+\";\r\n    position: absolute;\r\n    top: 13px;\r\n    right: 18px;\r\n    color: var(--ly-blue);\r\n    font-size: 27px;\r\n    font-weight: 500;\r\n  }\r\n\r\n  .ly-spd05-faq details[open] summary::after {\r\n    content: \"\u2212\";\r\n  }\r\n\r\n  .ly-spd05-faq-answer {\r\n    padding: 0 20px 19px;\r\n    color: #43515e;\r\n  }\r\n\r\n  .ly-spd05-faq-answer p:last-child {\r\n    margin-bottom: 0;\r\n  }\r\n\r\n  .ly-spd05-related {\r\n    display: grid;\r\n    grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    gap: 15px;\r\n    margin: 24px 0;\r\n  }\r\n\r\n  .ly-spd05-related a {\r\n    display: block;\r\n    padding: 18px 19px;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: 11px;\r\n    background: #ffffff;\r\n    color: #1b4774;\r\n    text-decoration: none;\r\n    font-weight: 700;\r\n  }\r\n\r\n  .ly-spd05-related a:hover,\r\n  .ly-spd05-related a:focus {\r\n    border-color: #9fc2e4;\r\n    background: var(--ly-blue-soft);\r\n  }\r\n\r\n  .ly-spd05-sources {\r\n    margin: 25px 0;\r\n    padding: 24px 26px;\r\n    border: 1px solid var(--ly-line);\r\n    border-radius: var(--ly-radius);\r\n    background: var(--ly-bg);\r\n  }\r\n\r\n  .ly-spd05-sources ol {\r\n    margin: 0;\r\n    padding-left: 22px;\r\n  }\r\n\r\n  .ly-spd05-sources li {\r\n    margin-bottom: 11px;\r\n    color: #465360;\r\n    font-size: 14px;\r\n    line-height: 1.55;\r\n  }\r\n\r\n  .ly-spd05-sources li:last-child {\r\n    margin-bottom: 0;\r\n  }\r\n\r\n  .ly-spd05-cta {\r\n    margin: 50px 0 10px;\r\n    padding: 28px 30px;\r\n    border-radius: var(--ly-radius);\r\n    background: #0e3157;\r\n    color: #ffffff;\r\n  }\r\n\r\n  .ly-spd05-cta h2 {\r\n    margin: 0 0 12px;\r\n    padding: 0;\r\n    border: 0;\r\n    color: #ffffff;\r\n    font-size: 26px;\r\n  }\r\n\r\n  .ly-spd05-cta p {\r\n    margin-bottom: 20px;\r\n    color: #e2ebf4;\r\n  }\r\n\r\n  .ly-spd05-actions {\r\n    display: flex;\r\n    flex-wrap: wrap;\r\n    gap: 12px;\r\n  }\r\n\r\n  .ly-spd05-btn {\r\n    display: inline-flex;\r\n    min-height: 48px;\r\n    align-items: center;\r\n    justify-content: center;\r\n    padding: 12px 21px;\r\n    border: 1px solid transparent;\r\n    border-radius: 7px;\r\n    cursor: pointer;\r\n    font-family: inherit;\r\n    font-size: 15px;\r\n    font-weight: 800;\r\n    line-height: 1.2;\r\n    text-align: center;\r\n    text-decoration: none !important;\r\n    transition: transform 0.2s ease, background 0.2s ease;\r\n  }\r\n\r\n  .ly-spd05-btn:hover,\r\n  .ly-spd05-btn:focus {\r\n    transform: translateY(-1px);\r\n  }\r\n\r\n  .ly-spd05-btn-primary {\r\n    border-color: #ffffff;\r\n    background: #ffffff;\r\n    color: var(--ly-blue-dark) !important;\r\n  }\r\n\r\n  .ly-spd05-btn-secondary {\r\n    border-color: rgba(255, 255, 255, 0.45);\r\n    background: transparent;\r\n    color: #ffffff !important;\r\n  }\r\n\r\n  .ly-spd05-disclaimer {\r\n    margin-top: 24px;\r\n    color: #66727d;\r\n    font-size: 13px;\r\n    line-height: 1.55;\r\n  }\r\n\r\n  \/* Desktop 1440 *\/\r\n  @media (min-width: 1440px) {\r\n    .ly-spd05 {\r\n      max-width: 1160px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      font-size: 32px;\r\n    }\r\n  }\r\n\r\n  \/* Desktop 1366 *\/\r\n  @media (min-width: 1366px) and (max-width: 1439px) {\r\n    .ly-spd05 {\r\n      max-width: 1120px;\r\n    }\r\n  }\r\n\r\n  \/* Desktop 1280 *\/\r\n  @media (min-width: 1280px) and (max-width: 1365px) {\r\n    .ly-spd05 {\r\n      max-width: 1060px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      font-size: 30px;\r\n    }\r\n  }\r\n\r\n  \/* Tablet 1024 *\/\r\n  @media (min-width: 1024px) and (max-width: 1279px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 52px);\r\n      font-size: 16.5px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      font-size: 29px;\r\n    }\r\n  }\r\n\r\n  \/* Tablet 912 *\/\r\n  @media (min-width: 912px) and (max-width: 1023px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 44px);\r\n      font-size: 16px;\r\n    }\r\n\r\n    .ly-spd05-grid {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n  }\r\n\r\n  \/* Tablet 820 *\/\r\n  @media (min-width: 820px) and (max-width: 911px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 38px);\r\n      font-size: 16px;\r\n    }\r\n\r\n    .ly-spd05-grid {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n  }\r\n\r\n  \/* Tablet 768 *\/\r\n  @media (min-width: 768px) and (max-width: 819px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 34px);\r\n      font-size: 16px;\r\n    }\r\n\r\n    .ly-spd05-lead {\r\n      font-size: 18px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2 {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n  }\r\n\r\n  \/* Mobile 600 *\/\r\n  @media (min-width: 600px) and (max-width: 767px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 30px);\r\n      font-size: 16px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      margin-top: 48px;\r\n      font-size: 26px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-toc ol,\r\n    .ly-spd05-checklist {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n  }\r\n\r\n  \/* Mobile 540 *\/\r\n  @media (min-width: 540px) and (max-width: 599px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 28px);\r\n      font-size: 16px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related,\r\n    .ly-spd05-checklist,\r\n    .ly-spd05-toc ol {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-definition-row {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n  }\r\n\r\n  \/* Mobile 480 *\/\r\n  @media (min-width: 480px) and (max-width: 539px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 26px);\r\n      font-size: 15.8px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related,\r\n    .ly-spd05-checklist,\r\n    .ly-spd05-toc ol {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-definition-row {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n\r\n    .ly-spd05-actions {\r\n      flex-direction: column;\r\n    }\r\n\r\n    .ly-spd05-btn {\r\n      width: 100%;\r\n    }\r\n  }\r\n\r\n  \/* Mobile 430 *\/\r\n  @media (min-width: 430px) and (max-width: 479px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 24px);\r\n      font-size: 15.6px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      font-size: 24px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related,\r\n    .ly-spd05-checklist,\r\n    .ly-spd05-toc ol {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-definition-row {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n\r\n    .ly-spd05-actions {\r\n      flex-direction: column;\r\n    }\r\n\r\n    .ly-spd05-btn {\r\n      width: 100%;\r\n    }\r\n  }\r\n\r\n  \/* Mobile 414 *\/\r\n  @media (min-width: 414px) and (max-width: 429px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 22px);\r\n      font-size: 15.5px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related,\r\n    .ly-spd05-checklist,\r\n    .ly-spd05-toc ol {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-definition-row {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n\r\n    .ly-spd05-actions {\r\n      flex-direction: column;\r\n    }\r\n\r\n    .ly-spd05-btn {\r\n      width: 100%;\r\n    }\r\n  }\r\n\r\n  \/* Mobile 390 *\/\r\n  @media (min-width: 390px) and (max-width: 413px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 20px);\r\n      font-size: 15.3px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      font-size: 23px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related,\r\n    .ly-spd05-checklist,\r\n    .ly-spd05-toc ol {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-definition-row {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n    }\r\n\r\n    .ly-spd05-actions {\r\n      flex-direction: column;\r\n    }\r\n\r\n    .ly-spd05-btn {\r\n      width: 100%;\r\n    }\r\n  }\r\n\r\n  \/* Mobile 375 *\/\r\n  @media (min-width: 375px) and (max-width: 389px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 18px);\r\n      font-size: 15.2px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      font-size: 22px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related,\r\n    .ly-spd05-checklist,\r\n    .ly-spd05-toc ol {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-definition-row {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: 1fr 1fr;\r\n    }\r\n\r\n    .ly-spd05-actions {\r\n      flex-direction: column;\r\n    }\r\n\r\n    .ly-spd05-btn {\r\n      width: 100%;\r\n    }\r\n  }\r\n\r\n  \/* Mobile 360 *\/\r\n  @media (min-width: 360px) and (max-width: 374px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 18px);\r\n      font-size: 15px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      font-size: 22px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related,\r\n    .ly-spd05-checklist,\r\n    .ly-spd05-toc ol {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-definition-row {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: 1fr 1fr;\r\n      gap: 8px;\r\n    }\r\n\r\n    .ly-spd05-actions {\r\n      flex-direction: column;\r\n    }\r\n\r\n    .ly-spd05-btn {\r\n      width: 100%;\r\n    }\r\n  }\r\n\r\n  \/* Mobile 320 *\/\r\n  @media (min-width: 320px) and (max-width: 359px) {\r\n    .ly-spd05 {\r\n      max-width: calc(100% - 14px);\r\n      font-size: 14.7px;\r\n      line-height: 1.64;\r\n    }\r\n\r\n    .ly-spd05-lead {\r\n      font-size: 16px;\r\n    }\r\n\r\n    .ly-spd05 h2 {\r\n      font-size: 21px;\r\n    }\r\n\r\n    .ly-spd05-grid,\r\n    .ly-spd05-grid-2,\r\n    .ly-spd05-related,\r\n    .ly-spd05-checklist,\r\n    .ly-spd05-toc ol {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-definition-row {\r\n      grid-template-columns: 1fr;\r\n    }\r\n\r\n    .ly-spd05-calculation {\r\n      grid-template-columns: 1fr;\r\n      gap: 8px;\r\n    }\r\n\r\n    .ly-spd05-actions {\r\n      flex-direction: column;\r\n    }\r\n\r\n    .ly-spd05-btn {\r\n      width: 100%;\r\n    }\r\n\r\n    .ly-spd05-table {\r\n      min-width: 700px;\r\n    }\r\n\r\n    .ly-spd05-formula-main {\r\n      font-size: 23px;\r\n    }\r\n\r\n    .ly-spd05-zoom {\r\n      right: 8px;\r\n      bottom: 8px;\r\n      min-height: 30px;\r\n      padding: 6px 8px;\r\n      font-size: 11px;\r\n    }\r\n  }\r\n<\/style>\r\n\r\n<article class=\"ly-spd05\">\r\n\r\n  <section class=\"ly-spd05-intro\" aria-label=\"Article introduction\">\r\n    <span class=\"ly-spd05-eyebrow\">\r\n      SPD Installation Guide for Panel Builders\r\n    <\/span>\r\n\r\n    <p class=\"ly-spd05-lead\">\r\n      <strong>SPD cable length directly affects the protection delivered inside a completed\r\n      distribution board.<\/strong> A surge protective device may have a low declared Up,\r\n      but long connection leads can add inductive voltage and expose downstream equipment\r\n      to a higher voltage than the SPD datasheet alone suggests.\r\n    <\/p>\r\n  <\/section>\r\n\r\n  <section class=\"ly-spd05-answer\" aria-label=\"Quick answer\">\r\n    <span class=\"ly-spd05-answer-title\">\r\n      Quick Answer\r\n    <\/span>\r\n\r\n    <p>\r\n      Keep the complete SPD connection path as short and direct as practical.\r\n      The commonly referenced <strong>0.5 m rule applies to the total relevant wiring\r\n      between the connection points of the SPD assembly<\/strong>, not automatically to each\r\n      individual conductor.\r\n    <\/p>\r\n\r\n    <p>\r\n      Where a separate backup fuse or circuit breaker is installed, the total may include\r\n      the conductor from the busbar to the backup device, the conductor from the backup\r\n      device to the SPD, and the conductor from the SPD to PE, PEN or neutral.\r\n    <\/p>\r\n\r\n    <p>\r\n      In BS 7671-based installations, the total should preferably not exceed 0.5 m and\r\n      should not exceed 1.0 m. Other markets must follow the applicable national rules and\r\n      the SPD manufacturer's instructions.\r\n    <\/p>\r\n  <\/section>\r\n\r\n  <div class=\"ly-spd05-keyline\">\r\n    <strong>A low SPD Up is only part of the protection design.<\/strong>\r\n    Panel layout and connection-lead length determine the installed result.\r\n  <\/div>\r\n\r\n  <nav class=\"ly-spd05-toc\" aria-label=\"In this guide\">\r\n    <span class=\"ly-spd05-toc-title\">\r\n      In This Guide\r\n    <\/span>\r\n\r\n    <ol>\r\n      <li><a href=\"#why-short\">Why SPD leads must be short<\/a><\/li>\r\n      <li><a href=\"#measure\">How to measure total cable length<\/a><\/li>\r\n      <li><a href=\"#worked-example\">Worked panel example<\/a><\/li>\r\n      <li><a href=\"#installed-up\">Up versus installed protection<\/a><\/li>\r\n      <li><a href=\"#panel-layout\">Correct panel layout<\/a><\/li>\r\n      <li><a href=\"#cannot-meet\">What to do if 0.5 m is not possible<\/a><\/li>\r\n      <li><a href=\"#ordering\">OEM and QC checklist<\/a><\/li>\r\n      <li><a href=\"#faq\">Frequently asked questions<\/a><\/li>\r\n    <\/ol>\r\n  <\/nav>\r\n\r\n  <section id=\"why-short\">\r\n    <div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/pt\/spd-cable-length-0-5m\/#why-must-spd-connection-cables-be-short\" >Why Must SPD Connection Cables Be Short?<\/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\/pt\/spd-cable-length-0-5m\/#how-is-the-spd-05-m-connection-length-measured\" >How Is the SPD 0.5 m Connection Length Measured?<\/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\/pt\/spd-cable-length-0-5m\/#worked-spd-cable-length-example\" >Worked SPD Cable-Length Example<\/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\/pt\/spd-cable-length-0-5m\/#how-does-cable-length-change-the-installed-protection-level\" >How Does Cable Length Change the Installed Protection Level?<\/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\/pt\/spd-cable-length-0-5m\/#how-should-an-spd-be-positioned-inside-a-distribution-board\" >How Should an SPD Be Positioned Inside a Distribution Board?<\/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\/pt\/spd-cable-length-0-5m\/#what-if-the-spd-connection-cannot-be-kept-within-05-m\" >What If the SPD Connection Cannot Be Kept Within 0.5 m?<\/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\/pt\/spd-cable-length-0-5m\/#panel-builder-and-oem-confirmation-checklist\" >Panel Builder and OEM Confirmation Checklist<\/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\/pt\/spd-cable-length-0-5m\/#frequently-asked-questions\" >Frequently Asked Questions<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"#\" data-href=\"https:\/\/www.cnspd.com\/pt\/spd-cable-length-0-5m\/#related-spd-technical-guides\" >Related SPD Technical Guides<\/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\/pt\/spd-cable-length-0-5m\/#technical-references\" >Technical References<\/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\/pt\/spd-cable-length-0-5m\/#need-to-confirm-an-spd-layout-for-your-panel\" >Need to Confirm an SPD Layout for Your Panel?<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"why-must-spd-connection-cables-be-short\"><\/span>Why Must SPD Connection Cables Be Short?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      Surge current rises much faster than normal 50 Hz or 60 Hz operating current.\r\n      At this high rate of change, the inductance of the connection conductors generates\r\n      additional voltage.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-formula\">\r\n      <span class=\"ly-spd05-formula-main\">\r\n        U<sub>lead<\/sub> = L<sub>lead<\/sub> \u00d7 di\/dt\r\n      <\/span>\r\n\r\n      <span class=\"ly-spd05-formula-small\">\r\n        U<sub>lead<\/sub> is the added voltage across the connection path,\r\n        L<sub>lead<\/sub> is the conductor inductance, and di\/dt is the surge-current\r\n        rate of rise.\r\n      <\/span>\r\n    <\/div>\r\n\r\n    <p>\r\n      A commonly used engineering approximation is about 1 \u03bcH of inductance per metre of\r\n      conductor. Under an 8\/20 \u03bcs surge-current example, this can correspond to approximately\r\n      1 kV of added voltage per metre of connection cable.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-warning\">\r\n      <span class=\"ly-spd05-label\">\r\n        This is an explanatory example, not a fixed field value\r\n      <\/span>\r\n\r\n      <p>\r\n        The actual added voltage depends on the surge magnitude, waveform, conductor route,\r\n        conductor spacing, loop area, terminals and complete SPD assembly. It is not correct\r\n        to state that every metre always adds exactly 1 kV.\r\n      <\/p>\r\n    <\/div>\r\n\r\n    <div class=\"ly-spd05-grid\">\r\n\r\n      <div class=\"ly-spd05-card\">\r\n        <span class=\"ly-spd05-card-number\">1<\/span>\r\n\r\n        <h3>Longer Path<\/h3>\r\n\r\n        <p>\r\n          A longer connection generally has more inductance and therefore produces more\r\n          added voltage during a fast surge.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-card\">\r\n        <span class=\"ly-spd05-card-number\">2<\/span>\r\n\r\n        <h3>Larger Loop Area<\/h3>\r\n\r\n        <p>\r\n          Conductors routed far apart or around large cabinet loops can further increase\r\n          the installation effect.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-card\">\r\n        <span class=\"ly-spd05-card-number\">3<\/span>\r\n\r\n        <h3>Thicker Cable Is Not Enough<\/h3>\r\n\r\n        <p>\r\n          Correct cross-section is necessary, but a thicker cable does not remove the\r\n          inductive effect of an unnecessarily long route.\r\n        <\/p>\r\n      <\/div>\r\n\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section id=\"measure\">\r\n    <h2><span class=\"ez-toc-section\" id=\"how-is-the-spd-05-m-connection-length-measured\"><\/span>How Is the SPD 0.5 m Connection Length Measured?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      The exact conductor sections depend on the SPD connection arrangement.\r\n      In the diagram below, <strong>L1, L2 and L3 identify lead sections<\/strong>.\r\n      They do not represent the three electrical phases.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-definition\">\r\n\r\n      <div class=\"ly-spd05-definition-row\">\r\n        <div class=\"ly-spd05-definition-term\">\r\n          Lead Section L1\r\n        <\/div>\r\n\r\n        <div class=\"ly-spd05-definition-desc\">\r\n          Conductor from the protected busbar, main conductor or branch point to a separate\r\n          SPD backup fuse or circuit breaker.\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-definition-row\">\r\n        <div class=\"ly-spd05-definition-term\">\r\n          Lead Section L2\r\n        <\/div>\r\n\r\n        <div class=\"ly-spd05-definition-desc\">\r\n          Conductor from the separate backup protective device to the SPD. Where no separate\r\n          device is required, this may be the direct conductor from the circuit connection\r\n          point to the SPD.\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-definition-row\">\r\n        <div class=\"ly-spd05-definition-term\">\r\n          Lead Section L3\r\n        <\/div>\r\n\r\n        <div class=\"ly-spd05-definition-desc\">\r\n          Conductor from the SPD to the applicable PE, PEN, neutral or equipotential-bonding\r\n          connection.\r\n        <\/div>\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ly-spd05-formula\">\r\n      <span class=\"ly-spd05-formula-main\">\r\n        L<sub>total<\/sub> = L1 + L2 + L3\r\n      <\/span>\r\n\r\n      <span class=\"ly-spd05-formula-small\">\r\n        Include only the conductor sections that form the applicable surge-current path\r\n        in the actual panel arrangement.\r\n      <\/span>\r\n    <\/div>\r\n\r\n    <h3>Without a Separate SPD Backup Device<\/h3>\r\n\r\n    <p>\r\n      Where the SPD manufacturer permits the upstream protective device to provide the\r\n      required backup protection, there may be no separate L1 section. The relevant total\r\n      may therefore be:\r\n    <\/p>\r\n\r\n    <p>\r\n      <strong>Busbar or branch point to SPD + SPD to PE, PEN or neutral.<\/strong>\r\n    <\/p>\r\n\r\n    <h3>With a Separate Backup Fuse or Circuit Breaker<\/h3>\r\n\r\n    <p>\r\n      Where a dedicated backup protective device is required, all applicable connection\r\n      sections must be considered:\r\n    <\/p>\r\n\r\n    <p>\r\n      <strong>\r\n        Busbar to backup device + backup device to SPD + SPD to PE, PEN or neutral.\r\n      <\/strong>\r\n    <\/p>\r\n\r\n    <h3>Three-Phase Panels<\/h3>\r\n\r\n    <p>\r\n      Do not add the physical lengths of all three phase conductors together as though they\r\n      were one continuous cable. Assess the applicable protection path for each mode and use\r\n      the longest relevant route.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-note\">\r\n      <span class=\"ly-spd05-label\">\r\n        Measure the installed conductor route\r\n      <\/span>\r\n\r\n      <p>\r\n        Do not measure the straight-line distance between the device housings. Follow the\r\n        actual cable route through terminals, backup protection and wire ducts.\r\n      <\/p>\r\n    <\/div>\r\n\r\n    <figure class=\"ly-spd05-figure\">\r\n      <a\r\n        class=\"ly-spd05-figure-link\"\r\n        href=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/spd-0-5m-total-connection-length-measurement.webp\"\r\n        target=\"_blank\"\r\n        rel=\"noopener\"\r\n        aria-label=\"Open the full-size SPD connection length measurement diagram\"\r\n      >\r\n        <img loading=\"lazy\"\r\n          src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/spd-0-5m-total-connection-length-measurement.webp\"\r\n          alt=\"How to measure total SPD connection lead length using L1 plus L2 plus L3\"\r\n          width=\"1600\"\r\n          height=\"900\"\r\n          loading=\"lazy\"\r\n          decoding=\"async\"\r\n        >\r\n\r\n        <span class=\"ly-spd05-zoom\">\r\n          Open Full-Size Image\r\n        <\/span>\r\n      <\/a>\r\n\r\n      <figcaption>\r\n        <strong>Figure 1.<\/strong>\r\n        The preferred 0.5 m target concerns the complete applicable connection path.\r\n        It should not be checked by measuring only the conductor from the SPD to the PE bar.\r\n      <\/figcaption>\r\n    <\/figure>\r\n  <\/section>\r\n\r\n  <section id=\"worked-example\">\r\n    <h2><span class=\"ez-toc-section\" id=\"worked-spd-cable-length-example\"><\/span>Worked SPD Cable-Length Example<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      A Type 2 SPD is installed beside a dedicated backup MCB. The PE bar is located below\r\n      the SPD.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-worked\">\r\n      <h3>Completed Panel Measurement<\/h3>\r\n\r\n      <div class=\"ly-spd05-calculation\">\r\n\r\n        <div class=\"ly-spd05-calc-item\">\r\n          <span class=\"ly-spd05-calc-symbol\">\r\n            L1\r\n          <\/span>\r\n\r\n          <span class=\"ly-spd05-calc-value\">\r\n            90 mm\r\n          <\/span>\r\n        <\/div>\r\n\r\n        <div class=\"ly-spd05-calc-item\">\r\n          <span class=\"ly-spd05-calc-symbol\">\r\n            L2\r\n          <\/span>\r\n\r\n          <span class=\"ly-spd05-calc-value\">\r\n            140 mm\r\n          <\/span>\r\n        <\/div>\r\n\r\n        <div class=\"ly-spd05-calc-item\">\r\n          <span class=\"ly-spd05-calc-symbol\">\r\n            L3\r\n          <\/span>\r\n\r\n          <span class=\"ly-spd05-calc-value\">\r\n            210 mm\r\n          <\/span>\r\n        <\/div>\r\n\r\n        <div class=\"ly-spd05-calc-item\">\r\n          <span class=\"ly-spd05-calc-symbol\">\r\n            Total\r\n          <\/span>\r\n\r\n          <span class=\"ly-spd05-calc-value\">\r\n            440 mm\r\n          <\/span>\r\n        <\/div>\r\n\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-worked-result\">\r\n        L1 + L2 + L3 = 440 mm. The completed route is within the preferred 0.5 m target,\r\n        subject to the applicable local rules and manufacturer instructions.\r\n      <\/div>\r\n    <\/div>\r\n\r\n    <p>\r\n      The same components could fail the target if the backup MCB were moved to another\r\n      DIN-rail section or if the PE conductor were routed across the full cabinet.\r\n      This is why the SPD position should be decided during panel layout\u2014not after the\r\n      remaining components have already been placed.\r\n    <\/p>\r\n  <\/section>\r\n\r\n  <section id=\"installed-up\">\r\n    <h2><span class=\"ez-toc-section\" id=\"how-does-cable-length-change-the-installed-protection-level\"><\/span>How Does Cable Length Change the Installed Protection Level?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      <strong>Up<\/strong> is the voltage protection level declared for the SPD under defined\r\n      test conditions. The downstream equipment may see a higher voltage after connection\r\n      effects are included.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-formula\">\r\n      <span class=\"ly-spd05-formula-main\">\r\n        U<sub>equipment<\/sub> \u2248 U<sub>p<\/sub> + U<sub>connection<\/sub>\r\n      <\/span>\r\n\r\n      <span class=\"ly-spd05-formula-small\">\r\n        This simplified relationship shows why the installed result can be higher than the\r\n        SPD's declared Up.\r\n      <\/span>\r\n    <\/div>\r\n\r\n    <div\r\n      class=\"ly-spd05-table-wrap\"\r\n      role=\"region\"\r\n      aria-label=\"Illustrative effect of SPD connection length\"\r\n      tabindex=\"0\"\r\n    >\r\n      <table class=\"ly-spd05-table\">\r\n        <thead>\r\n          <tr>\r\n            <th>Total Connection Length<\/th>\r\n            <th>Illustrative Added Voltage<\/th>\r\n            <th>Example with SPD Up = 1.5 kV<\/th>\r\n            <th>Panel Interpretation<\/th>\r\n          <\/tr>\r\n        <\/thead>\r\n\r\n        <tbody>\r\n          <tr>\r\n            <td>0.25 m<\/td>\r\n            <td>Approximately 0.25 kV<\/td>\r\n            <td>Approximately 1.75 kV<\/td>\r\n            <td>Short connection with a smaller installation penalty.<\/td>\r\n          <\/tr>\r\n\r\n          <tr>\r\n            <td>0.50 m<\/td>\r\n            <td>Approximately 0.50 kV<\/td>\r\n            <td>Approximately 2.00 kV<\/td>\r\n            <td>Common preferred connection-length target.<\/td>\r\n          <\/tr>\r\n\r\n          <tr>\r\n            <td>1.00 m<\/td>\r\n            <td>Approximately 1.00 kV<\/td>\r\n            <td>Approximately 2.50 kV<\/td>\r\n            <td>Protection margin may be significantly reduced.<\/td>\r\n          <\/tr>\r\n        <\/tbody>\r\n      <\/table>\r\n    <\/div>\r\n\r\n    <p class=\"ly-spd05-table-note\">\r\n      The table uses an illustrative approximation of about 1 kV per metre.\r\n      It is not a guaranteed product or field-performance calculation.\r\n    <\/p>\r\n\r\n    <figure class=\"ly-spd05-figure\">\r\n      <a\r\n        class=\"ly-spd05-figure-link\"\r\n        href=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/spd-up-vs-installed-protection-lead-voltage.webp\"\r\n        target=\"_blank\"\r\n        rel=\"noopener\"\r\n        aria-label=\"Open the full-size SPD Up and installed protection diagram\"\r\n      >\r\n        <img loading=\"lazy\"\r\n          src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/spd-up-vs-installed-protection-lead-voltage.webp\"\r\n          alt=\"SPD Up versus installed protection level with additional cable inductive voltage\"\r\n          width=\"1600\"\r\n          height=\"900\"\r\n          loading=\"lazy\"\r\n          decoding=\"async\"\r\n        >\r\n\r\n        <span class=\"ly-spd05-zoom\">\r\n          Open Full-Size Image\r\n        <\/span>\r\n      <\/a>\r\n\r\n      <figcaption>\r\n        <strong>Figure 2.<\/strong>\r\n        A low declared Up does not guarantee the same protection after installation.\r\n        Connection-induced voltage must also remain compatible with the impulse withstand\r\n        voltage of the protected equipment.\r\n      <\/figcaption>\r\n    <\/figure>\r\n\r\n    <div class=\"ly-spd05-success\">\r\n      <span class=\"ly-spd05-label\">\r\n        Better engineering question\r\n      <\/span>\r\n\r\n      <p>\r\n        Do not ask only, \u201cWhat is the SPD Up?\u201d Ask, \u201cWhat protection level will the selected\r\n        SPD and the proposed panel connection arrangement deliver together?\u201d\r\n      <\/p>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section id=\"panel-layout\">\r\n    <h2><span class=\"ez-toc-section\" id=\"how-should-an-spd-be-positioned-inside-a-distribution-board\"><\/span>How Should an SPD Be Positioned Inside a Distribution Board?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      The SPD, backup protective device and PE connection should be planned as one functional\r\n      assembly. Installing the SPD in the last available DIN-rail position often creates a\r\n      poor connection path.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-steps\">\r\n\r\n      <div class=\"ly-spd05-step\">\r\n        <h3>Identify the Protected Connection Point<\/h3>\r\n\r\n        <p>\r\n          Confirm where the SPD branch will leave the incoming conductor, busbar or\r\n          distribution terminal.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-step\">\r\n        <h3>Position the Backup Device Beside the SPD<\/h3>\r\n\r\n        <p>\r\n          Where dedicated backup protection is required, a remote fuse or circuit breaker\r\n          can consume most of the permitted connection length.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-step\">\r\n        <h3>Keep the PE Path Short and Direct<\/h3>\r\n\r\n        <p>\r\n          Place the SPD close to an appropriate PE, PEN or bonding connection rather than\r\n          routing the conductor across the cabinet.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-step\">\r\n        <h3>Avoid Loops and Unnecessary Wire-Duct Routes<\/h3>\r\n\r\n        <p>\r\n          Do not store excess cable beside the SPD. Cut conductors to the required length and\r\n          minimise the area enclosed by the surge-current path.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-step\">\r\n        <h3>Reserve Maintenance Clearance<\/h3>\r\n\r\n        <p>\r\n          Keep the indicator, terminals, remote contact and pluggable cartridge accessible\r\n          after wiring is completed.\r\n        <\/p>\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <figure class=\"ly-spd05-figure\">\r\n      <a\r\n        class=\"ly-spd05-figure-link\"\r\n        href=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/correct-vs-wrong-spd-panel-cable-layout.webp\"\r\n        target=\"_blank\"\r\n        rel=\"noopener\"\r\n        aria-label=\"Open the full-size correct and incorrect SPD panel layout diagram\"\r\n      >\r\n        <img loading=\"lazy\"\r\n          src=\"https:\/\/www.cnspd.com\/wp-content\/uploads\/2026\/07\/correct-vs-wrong-spd-panel-cable-layout.webp\"\r\n          alt=\"Correct versus incorrect SPD cable routing and placement inside a distribution board\"\r\n          width=\"1600\"\r\n          height=\"900\"\r\n          loading=\"lazy\"\r\n          decoding=\"async\"\r\n        >\r\n\r\n        <span class=\"ly-spd05-zoom\">\r\n          Open Full-Size Image\r\n        <\/span>\r\n      <\/a>\r\n\r\n      <figcaption>\r\n        <strong>Figure 3.<\/strong>\r\n        The optimised layout shortens the active-side connection, backup-protection wiring\r\n        and PE path while preserving terminal and cartridge access.\r\n      <\/figcaption>\r\n    <\/figure>\r\n  <\/section>\r\n\r\n  <section id=\"cannot-meet\">\r\n    <h2><span class=\"ez-toc-section\" id=\"what-if-the-spd-connection-cannot-be-kept-within-05-m\"><\/span>What If the SPD Connection Cannot Be Kept Within 0.5 m?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      Do not try to solve an excessive connection path only by increasing the cable\r\n      cross-section. Review the physical arrangement first.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-grid-2\">\r\n\r\n      <div class=\"ly-spd05-card\">\r\n        <h3>Reposition the SPD<\/h3>\r\n\r\n        <p>\r\n          Move the SPD nearer to both the protected busbar and the relevant PE, PEN or neutral\r\n          connection.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-card\">\r\n        <h3>Move the Backup Protection<\/h3>\r\n\r\n        <p>\r\n          Place the dedicated fuse or circuit breaker directly beside the SPD where the\r\n          product instructions allow it.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-card\">\r\n        <h3>Use a Permitted V-Connection<\/h3>\r\n\r\n        <p>\r\n          A suitable V-type or feed-through connection can reduce the effect of long branch\r\n          conductors, but only when the SPD terminals and manufacturer instructions permit it.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-card\">\r\n        <h3>Use an Integrated Assembly<\/h3>\r\n\r\n        <p>\r\n          An SPD with integrated backup protection may remove external conductor sections\r\n          and simplify compliance with the connection-length target.\r\n        <\/p>\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ly-spd05-warning\">\r\n      <span class=\"ly-spd05-label\">\r\n        Do not create a new safety problem\r\n      <\/span>\r\n\r\n      <p>\r\n        Do not remove required backup protection, exceed terminal current ratings or treat\r\n        a normal parallel SPD as a full-load series device merely to shorten the wiring.\r\n      <\/p>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section id=\"ordering\">\r\n    <h2><span class=\"ez-toc-section\" id=\"panel-builder-and-oem-confirmation-checklist\"><\/span>Panel Builder and OEM Confirmation Checklist<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      Connection length should be considered before the panel drawing and bill of materials\r\n      are released.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-checklist\">\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        SPD pole configuration and module width confirmed.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        Terminal position and conductor-entry direction confirmed.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        External or integrated backup protection confirmed.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        Required conductor size and terminal capacity confirmed.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        SPD, backup device and PE-bar positions shown on the layout.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        Total installed lead length checked on the drawing.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        Cable-bending and terminal-access space reserved.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        Cartridge replacement clearance reserved.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        Completed wiring photographed during final QC.\r\n      <\/div>\r\n\r\n      <div class=\"ly-spd05-check\">\r\n        Final connection length recorded in the panel QC file.\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ly-spd05-note\">\r\n      <span class=\"ly-spd05-label\">\r\n        Example RFQ wording\r\n      <\/span>\r\n\r\n      <p>\r\n        Please confirm the SPD module width, backup-protection requirement, terminal conductor\r\n        capacity, permitted connection arrangement and installation drawing. Our panel target\r\n        is a complete applicable SPD connection path within 0.5 m.\r\n      <\/p>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section id=\"faq\">\r\n    <h2><span class=\"ez-toc-section\" id=\"frequently-asked-questions\"><\/span>Frequently Asked Questions<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <div class=\"ly-spd05-faq\">\r\n\r\n      <details>\r\n        <summary>Does every SPD conductor have to be shorter than 0.5 m?<\/summary>\r\n\r\n        <div class=\"ly-spd05-faq-answer\">\r\n          <p>\r\n            No. The commonly referenced 0.5 m value normally concerns the total applicable\r\n            connection path between the connection points of the SPD assembly.\r\n          <\/p>\r\n        <\/div>\r\n      <\/details>\r\n\r\n      <details>\r\n        <summary>Is only the SPD earth cable included in the measurement?<\/summary>\r\n\r\n        <div class=\"ly-spd05-faq-answer\">\r\n          <p>\r\n            No. The active-side conductor and the wiring through a separate backup protective\r\n            device may also form part of the total path.\r\n          <\/p>\r\n        <\/div>\r\n      <\/details>\r\n\r\n      <details>\r\n        <summary>Can a thicker cable compensate for a long SPD connection?<\/summary>\r\n\r\n        <div class=\"ly-spd05-faq-answer\">\r\n          <p>\r\n            Not fully. Correct conductor size is necessary, but increasing cross-section does\r\n            not remove the inductive effect of excessive length and loop area.\r\n          <\/p>\r\n        <\/div>\r\n      <\/details>\r\n\r\n      <details>\r\n        <summary>Should the three phase-conductor lengths be added together?<\/summary>\r\n\r\n        <div class=\"ly-spd05-faq-answer\">\r\n          <p>\r\n            Normally no. The three phase conductors are generally alternative parallel paths,\r\n            not one continuous series path. Check each applicable protection mode and use the\r\n            longest relevant path.\r\n          <\/p>\r\n        <\/div>\r\n      <\/details>\r\n\r\n      <details>\r\n        <summary>What happens if the total connection path is 1 m?<\/summary>\r\n\r\n        <div class=\"ly-spd05-faq-answer\">\r\n          <p>\r\n            The connection-induced voltage may significantly increase the installed protection\r\n            level. In BS 7671-based installations, 1 m is stated as the outer limit rather than\r\n            the preferred design target.\r\n          <\/p>\r\n        <\/div>\r\n      <\/details>\r\n\r\n      <details>\r\n        <summary>What is the difference between the 0.5 m rule and the 10 m rule?<\/summary>\r\n\r\n        <div class=\"ly-spd05-faq-answer\">\r\n          <p>\r\n            The 0.5 m guidance concerns the SPD's own connection path. The separate 10 m\r\n            concept concerns the distance between an SPD and remote equipment or another\r\n            distribution point, where additional coordinated protection may need to be assessed.\r\n          <\/p>\r\n        <\/div>\r\n      <\/details>\r\n\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section>\r\n    <h2><span class=\"ez-toc-section\" id=\"related-spd-technical-guides\"><\/span>Related SPD Technical Guides<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <div class=\"ly-spd05-related\">\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 Guide\r\n      <\/a>\r\n\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\/spd-selection-guide\/\"\r\n        target=\"_blank\"\r\n        rel=\"noopener\"\r\n      >\r\n        Complete SPD Selection Guide\r\n      <\/a>\r\n\r\n      <a\r\n        href=\"https:\/\/www.cnspd.com\/spd-for-distribution-board\/\"\r\n        target=\"_blank\"\r\n        rel=\"noopener\"\r\n      >\r\n        SPD for Distribution Boards\r\n      <\/a>\r\n\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <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-spd05-sources\">\r\n      <ol>\r\n        <li>\r\n          IEC 60364-5-53:2019+AMD1:2020+AMD2:2024, low-voltage electrical\r\n          installations and selection and 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\"\r\n          >\r\n            Official IEC publication page\r\n          <\/a>.\r\n        <\/li>\r\n\r\n        <li>\r\n          IEC 61643-11:2025, surge protective devices connected to AC low-voltage\r\n          power systems\u2014requirements and test methods.\r\n          <a\r\n            href=\"https:\/\/webstore.iec.ch\/en\/publication\/65314\"\r\n            target=\"_blank\"\r\n            rel=\"noopener\"\r\n          >\r\n            Official IEC publication page\r\n          <\/a>.\r\n        <\/li>\r\n\r\n        <li>\r\n          IET, BS 7671:2018 Myth Busting Webinar Q&amp;A, explanation of the preferred\r\n          0.5 m and maximum 1.0 m conductor length.\r\n          <a\r\n            href=\"https:\/\/electrical.theiet.org\/media\/2188\/spd-afdd-qa-3005.pdf\"\r\n            target=\"_blank\"\r\n            rel=\"noopener\"\r\n          >\r\n            View IET document\r\n          <\/a>.\r\n        <\/li>\r\n\r\n        <li>\r\n          Electrical Installation Guide, Connection of Surge Protection Device,\r\n          including total connection length, lead inductance and installed protection level.\r\n          <a\r\n            href=\"https:\/\/www.electrical-installation.org\/enwiki\/Connection_of_Surge_Protection_Device\"\r\n            target=\"_blank\"\r\n            rel=\"noopener\"\r\n          >\r\n            View technical guide\r\n          <\/a>.\r\n        <\/li>\r\n\r\n        <li>\r\n          Mersen, Surge Protection Solutions, guidance on the effect of longer SPD\r\n          lead lengths on clamping performance.\r\n          <a\r\n            href=\"https:\/\/www.mersen.com\/en\/surge-protection-solutions\"\r\n            target=\"_blank\"\r\n            rel=\"noopener\"\r\n          >\r\n            View Mersen guidance\r\n          <\/a>.\r\n        <\/li>\r\n      <\/ol>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section class=\"ly-spd05-cta\" aria-label=\"Request SPD panel support\">\r\n    <h2><span class=\"ez-toc-section\" id=\"need-to-confirm-an-spd-layout-for-your-panel\"><\/span>Need to Confirm an SPD Layout for Your Panel?<span class=\"ez-toc-section-end\"><\/span><\/h2>\r\n\r\n    <p>\r\n      Send the panel drawing, system voltage, earthing arrangement, SPD position,\r\n      backup-protection arrangement and PE-bar position. LEEYEE can help confirm the\r\n      product configuration and information required for an OEM or project quotation.\r\n    <\/p>\r\n\r\n    <div class=\"ly-spd05-actions\">\r\n\r\n      <button\r\n        type=\"button\"\r\n        class=\"ly-spd05-btn ly-spd05-btn-primary leeyee-site-popup-btn\"\r\n        aria-label=\"Request an SPD panel layout review\"\r\n      >\r\n        <span class=\"w-btn-label\">\r\n          Request a Panel Layout Review\r\n        <\/span>\r\n      <\/button>\r\n\r\n      <a\r\n        class=\"ly-spd05-btn ly-spd05-btn-secondary\"\r\n        href=\"https:\/\/www.cnspd.com\/spd-selection-guide\/\"\r\n        target=\"_blank\"\r\n        rel=\"noopener\"\r\n      >\r\n        <span>\r\n          View SPD Selection Guide\r\n        <\/span>\r\n      <\/a>\r\n\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <p class=\"ly-spd05-disclaimer\">\r\n    This article provides general engineering and procurement guidance. Final SPD selection,\r\n    wiring, conductor sizing, backup protection and verification must follow the project\r\n    design, applicable national regulations, panel assembly requirements and the specific\r\n    SPD manufacturer's instructions.\r\n  <\/p>\r\n\r\n<\/article>\r\n\r\n<script>\r\n  document.addEventListener('DOMContentLoaded', function () {\r\n    var popupButtons = document.querySelectorAll('.leeyee-site-popup-btn');\r\n\r\n    popupButtons.forEach(function (button) {\r\n      button.addEventListener('click', function () {\r\n        var realPopupTrigger = document.querySelector(\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>SPD Installation Guide for Panel Builders SPD cable length directly affects the protection delivered inside a completed distribution board. A surge protective device may have a low declared Up, but long connection leads can add inductive voltage and expose downstream equipment to a higher voltage than the SPD datasheet alone suggests. Quick Answer Keep the&#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-30070","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 v27.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>SPD Cable Length &amp; 0.5 m Rule: Panel Wiring Guide<\/title>\n<meta name=\"description\" content=\"SPD cable length affects installed protection. Learn the 0.5 m rule, measure the total connection path, and reduce inductive voltage in panels.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.cnspd.com\/pt\/spd-cable-length-0-5m\/\" \/>\n<meta property=\"og:locale\" content=\"pt_PT\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"SPD Cable Length &amp; 0.5 m Rule: Panel Wiring Guide\" \/>\n<meta property=\"og:description\" content=\"SPD cable length affects installed protection. Learn the 0.5 m rule, measure the total connection path, and reduce inductive voltage in panels.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.cnspd.com\/pt\/spd-cable-length-0-5m\/\" \/>\n<meta property=\"og:site_name\" content=\"Surge Protector, Surge Arrestor, Isolating Switch - LEEYEE\" \/>\n<meta property=\"article:published_time\" content=\"2026-07-15T05:24:52+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-07-15T07:14:52+00:00\" \/>\n<meta name=\"author\" content=\"Devin Ling\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Escrito por\" \/>\n\t<meta name=\"twitter:data1\" content=\"Devin Ling\" \/>\n\t<meta name=\"twitter:label2\" content=\"Tempo estimado de leitura\" \/>\n\t<meta name=\"twitter:data2\" content=\"10 minutos\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/spd-cable-length-0-5m\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/spd-cable-length-0-5m\\\/\"},\"author\":{\"name\":\"Devin Ling\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#\\\/schema\\\/person\\\/f49dbafe62c5b47100ad2d9f88af92d3\"},\"headline\":\"SPD Cable Length: How Panel Builders Apply the 0.5 m Rule\",\"datePublished\":\"2026-07-15T05:24:52+00:00\",\"dateModified\":\"2026-07-15T07:14:52+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/spd-cable-length-0-5m\\\/\"},\"wordCount\":1902,\"articleSection\":[\"News\",\"Surge Protection\",\"Technical Guides\"],\"inLanguage\":\"pt-PT\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/spd-cable-length-0-5m\\\/\",\"url\":\"https:\\\/\\\/www.cnspd.com\\\/spd-cable-length-0-5m\\\/\",\"name\":\"SPD Cable Length & 0.5 m Rule: Panel Wiring Guide\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#website\"},\"datePublished\":\"2026-07-15T05:24:52+00:00\",\"dateModified\":\"2026-07-15T07:14:52+00:00\",\"author\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#\\\/schema\\\/person\\\/f49dbafe62c5b47100ad2d9f88af92d3\"},\"description\":\"SPD cable length affects installed protection. Learn the 0.5 m rule, measure the total connection path, and reduce inductive voltage in panels.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/spd-cable-length-0-5m\\\/#breadcrumb\"},\"inLanguage\":\"pt-PT\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.cnspd.com\\\/spd-cable-length-0-5m\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/spd-cable-length-0-5m\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.cnspd.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"SPD Cable Length: How Panel Builders Apply the 0.5 m Rule\"}]},{\"@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\":\"pt-PT\"},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.cnspd.com\\\/#\\\/schema\\\/person\\\/f49dbafe62c5b47100ad2d9f88af92d3\",\"name\":\"Devin Ling\",\"sameAs\":[\"https:\\\/\\\/cnspd.com\\\/\"],\"url\":\"https:\\\/\\\/www.cnspd.com\\\/pt\\\/author\\\/devin\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"SPD Cable Length & 0.5 m Rule: Panel Wiring Guide","description":"SPD cable length affects installed protection. Learn the 0.5 m rule, measure the total connection path, and reduce inductive voltage in panels.","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\/pt\/spd-cable-length-0-5m\/","og_locale":"pt_PT","og_type":"article","og_title":"SPD Cable Length & 0.5 m Rule: Panel Wiring Guide","og_description":"SPD cable length affects installed protection. Learn the 0.5 m rule, measure the total connection path, and reduce inductive voltage in panels.","og_url":"https:\/\/www.cnspd.com\/pt\/spd-cable-length-0-5m\/","og_site_name":"Surge Protector, Surge Arrestor, Isolating Switch - LEEYEE","article_published_time":"2026-07-15T05:24:52+00:00","article_modified_time":"2026-07-15T07:14:52+00:00","author":"Devin Ling","twitter_card":"summary_large_image","twitter_misc":{"Escrito por":"Devin Ling","Tempo estimado de leitura":"10 minutos"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.cnspd.com\/spd-cable-length-0-5m\/#article","isPartOf":{"@id":"https:\/\/www.cnspd.com\/spd-cable-length-0-5m\/"},"author":{"name":"Devin Ling","@id":"https:\/\/www.cnspd.com\/#\/schema\/person\/f49dbafe62c5b47100ad2d9f88af92d3"},"headline":"SPD Cable Length: How Panel Builders Apply the 0.5 m Rule","datePublished":"2026-07-15T05:24:52+00:00","dateModified":"2026-07-15T07:14:52+00:00","mainEntityOfPage":{"@id":"https:\/\/www.cnspd.com\/spd-cable-length-0-5m\/"},"wordCount":1902,"articleSection":["News","Surge Protection","Technical Guides"],"inLanguage":"pt-PT"},{"@type":"WebPage","@id":"https:\/\/www.cnspd.com\/spd-cable-length-0-5m\/","url":"https:\/\/www.cnspd.com\/spd-cable-length-0-5m\/","name":"SPD Cable Length & 0.5 m Rule: Panel Wiring Guide","isPartOf":{"@id":"https:\/\/www.cnspd.com\/#website"},"datePublished":"2026-07-15T05:24:52+00:00","dateModified":"2026-07-15T07:14:52+00:00","author":{"@id":"https:\/\/www.cnspd.com\/#\/schema\/person\/f49dbafe62c5b47100ad2d9f88af92d3"},"description":"SPD cable length affects installed protection. Learn the 0.5 m rule, measure the total connection path, and reduce inductive voltage in panels.","breadcrumb":{"@id":"https:\/\/www.cnspd.com\/spd-cable-length-0-5m\/#breadcrumb"},"inLanguage":"pt-PT","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.cnspd.com\/spd-cable-length-0-5m\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.cnspd.com\/spd-cable-length-0-5m\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.cnspd.com\/"},{"@type":"ListItem","position":2,"name":"SPD Cable Length: How Panel Builders Apply the 0.5 m Rule"}]},{"@type":"WebSite","@id":"https:\/\/www.cnspd.com\/#website","url":"https:\/\/www.cnspd.com\/","name":"Protetor de sobretens\u00e3o, protetor de sobretens\u00e3o, interrutor de isolamento - LEEYEE","description":"Protetor de sobretens\u00e3o, protetor de sobretens\u00e3o, interrutor de isolamento - 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":"pt-PT"},{"@type":"Person","@id":"https:\/\/www.cnspd.com\/#\/schema\/person\/f49dbafe62c5b47100ad2d9f88af92d3","name":"Devin Ling","sameAs":["https:\/\/cnspd.com\/"],"url":"https:\/\/www.cnspd.com\/pt\/author\/devin\/"}]}},"_links":{"self":[{"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/posts\/30070","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/users\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/comments?post=30070"}],"version-history":[{"count":3,"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/posts\/30070\/revisions"}],"predecessor-version":[{"id":30076,"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/posts\/30070\/revisions\/30076"}],"wp:attachment":[{"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/media?parent=30070"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/categories?post=30070"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cnspd.com\/pt\/wp-json\/wp\/v2\/tags?post=30070"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}