{"id":100048,"date":"2026-02-15T20:09:16","date_gmt":"2026-02-15T20:09:16","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100048"},"modified":"2026-07-11T22:26:24","modified_gmt":"2026-07-11T22:26:24","slug":"cable-cross-section","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/nb\/calculators\/cable-cross-section\/","title":{"rendered":"Kontroll av kandidat for kabelspenningsfall | R\/X og effektfaktor"},"content":{"rendered":"\r\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Candidate Cable Voltage-Drop Check\",\"description\":\"Calculate steady-state voltage drop and conductor loss for a candidate cable using user-supplied operating resistance and reactance. 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}\r\n.vc-promo-link:hover { background:var(--vc-accent-hover); }\r\n\r\n\/* \u2500\u2500 FOOTER \u2500\u2500 *\/\r\n.vc-footer { text-align:center; padding:32px 16px; font-size:13px; color:var(--vc-ink-muted); }\r\n.vc-footer a { color:var(--vc-accent); text-decoration:none; }\r\n.vc-footer a:hover { text-decoration:underline; }\r\n.vc-footer-links { margin-top:8px; font-size:12px; }\r\n.vc-footer-links a { margin:0 8px; }\r\n\r\n\/* \u2500\u2500 PRINT \u2500\u2500 *\/\r\n@media print {\r\n    .vc-section-body { max-height:none!important; }\r\n    .vc-faq-a { max-height:none!important; }\r\n    .vc-results { max-height:none!important; padding:24px!important; }\r\n    .vc-copy-btn, .vc-section-chevron, .vc-faq-chevron, .vc-presets, .vc-promo { display:none!important; }\r\n}\r\n<\/style>\r\n<div class=\"vc-calculator\" id=\"vc-cable-drop\"><header class=\"vc-header\"><p class=\"vc-header-eyebrow\">Candidate-cable arithmetic<\/p><h1 class=\"vc-header-title\">Cable Voltage-Drop Candidate Check<\/h1><p class=\"vc-header-subtitle\">Calculate steady-state voltage drop from operating R\/X data for a candidate cable. This page does not select conductor cross-section, ampacity or protection.<\/p><div class=\"vc-badges\"><span class=\"vc-badge\">IEC 60228:2023 scope<\/span><span class=\"vc-badge\">IEC 60364-5-52 context<\/span><span class=\"vc-badge\">No generic ampacity table<\/span><\/div><\/header>\r\n<div class=\"vc-card\"><form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\"><div class=\"vc-form-grid\"><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-system\">Circuit model<\/label><select class=\"vc-select\" id=\"vc-system\"><option value=\"dc\">Two-wire DC<\/option><option value=\"ac1\">Single-phase AC (two conductors)<\/option><option value=\"ac3\">Balanced three-phase AC<\/option><\/select><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-current\">Load current I <span class=\"vc-label-hint\">(A)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-current\" inputmode=\"decimal\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-length\">One-way route length L <span class=\"vc-label-hint\">(m)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-length\" inputmode=\"decimal\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-voltage\">Reference load voltage U <span class=\"vc-label-hint\">(V; line-line for 3\u03c6)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-voltage\" inputmode=\"decimal\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-resistance\">Operating conductor resistance R\u2032 <span class=\"vc-label-hint\">(\u03a9\/km per conductor)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-resistance\" inputmode=\"decimal\"><\/div><div class=\"vc-field vc-ac-field\"><label class=\"vc-label\" for=\"vc-reactance\">Conductor reactance X\u2032 <span class=\"vc-label-hint\">(\u03a9\/km; zero allowed)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-reactance\" inputmode=\"decimal\"><\/div><div class=\"vc-field vc-ac-field\"><label class=\"vc-label\" for=\"vc-pf\">Lagging displacement power factor cos\u03c6<\/label><input class=\"vc-input\" type=\"text\" id=\"vc-pf\" inputmode=\"decimal\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-limit\">Entered maximum steady-state drop <span class=\"vc-label-hint\">(%)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-limit\" inputmode=\"decimal\"><\/div><\/div><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>Candidate data:<\/strong> use R\u2032 at the applicable conductor operating temperature and X\u2032 at the applicable frequency\/configuration from cable-maker data or a qualified calculation. The AC model is for sinusoidal current with lagging displacement power factor; it does not model leading power factor, harmonics or unbalance.<\/p><\/div><\/form>\r\n<div class=\"vc-results\" id=\"vc-results\"><div class=\"vc-results-head\"><h2 class=\"vc-results-title\">Steady-state candidate result<\/h2><button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\">Copy<\/button><\/div><div class=\"vc-result-grid\"><div class=\"vc-rcard vc-rcard-primary\"><div class=\"vc-rcard-label\">Comparison with entered drop limit<\/div><div class=\"vc-rcard-value\" id=\"vc-r-check\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Calculated voltage drop \u0394U<\/div><div class=\"vc-rcard-value\" id=\"vc-r-drop\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Calculated voltage drop<\/div><div class=\"vc-rcard-value\" id=\"vc-r-pct\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Series term R\u2032cos\u03c6 + X\u2032sin\u03c6<\/div><div class=\"vc-rcard-value\" id=\"vc-r-term\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Conductor I\u00b2R loss over circuit<\/div><div class=\"vc-rcard-value\" id=\"vc-r-loss\">\u2014<\/div><\/div><\/div><p id=\"vc-r-note\" style=\"margin:0;color:var(--vc-ink-secondary)\"><\/p><\/div><\/div>\r\n<div class=\"vc-section vc-open\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udcd8<\/span><span class=\"vc-section-title\">Equations and standards boundary<\/span><\/span><\/button><div class=\"vc-section-body\"><div class=\"vc-section-inner vc-theory\"><h3>Steady-state equations<\/h3><div class=\"vc-formula-box\">2-wire DC: \u0394U = 2ILR\u2032\/1000<\/div><div class=\"vc-formula-box\">1\u03c6 AC: \u0394U = 2IL(R\u2032cos\u03c6 + X\u2032sin\u03c6)\/1000<\/div><div class=\"vc-formula-box\">balanced 3\u03c6 AC: \u0394U = \u221a3IL(R\u2032cos\u03c6 + X\u2032sin\u03c6)\/1000<\/div><p>L is one-way metres and R\u2032\/X\u2032 are per-conductor \u03a9\/km. For DC the displayed series term is R\u2032. Circuit conductor loss is 2I\u00b2R\u2032L\/1000 for two-wire DC\/1\u03c6 and 3I\u00b2R\u2032L\/1000 for balanced 3\u03c6. These are candidate-circuit calculations, not short-circuit loop calculations.<\/p><p>The equations follow the steady-load formulation in the <a href=\"https:\/\/www.electrical-installation.org\/enwiki\/Calculation_of_voltage_drop_in_steady_load_conditions\" target=\"_blank\" rel=\"noopener\">Schneider Electric Electrical Installation Guide<\/a>.<\/p>\r\n<h3>IEC scope, editions and tables<\/h3><p><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/71891\" target=\"_blank\" rel=\"noopener\">IEC 60228:2023, edition 4<\/a> specifies nominal conductor cross-sectional areas from 0.5 to 3500 mm\u00b2 plus construction and resistance requirements. It does not by itself select a safe installed cable and does not establish an AWG equivalence table.<\/p><p><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/1878\" target=\"_blank\" rel=\"noopener\">IEC 60364-5-52:2009 with Amendment 1:2024<\/a> covers wiring-system selection\/erection, current-carrying capacity, harmonics and voltage drop. Exact values and national rules must be obtained from the licensed standard and applicable local implementation; this page reproduces no normative ampacity or voltage-drop table.<\/p><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>No cable approval:<\/strong> verify installation method, conductor count, insulation and temperature limits, ambient\/grouping\/soil factors, harmonic neutral loading, protective-device coordination, fault-loop impedance, automatic disconnection, short-circuit thermal withstand, minimum mechanical size, voltage-drop limits for the whole installation, terminals, parallel conductors and applicable national code.<\/p><\/div><\/div><\/div><\/div>\r\n<div class=\"vc-section\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\u2753<\/span><span class=\"vc-section-title\">Frequently Asked Questions<\/span><\/span><\/button><div class=\"vc-section-body\"><div class=\"vc-section-inner\"><div class=\"vc-faq-list\" id=\"vc-faq-list\"><\/div><\/div><\/div><\/div><footer class=\"vc-footer\"><p>\u00a9 2024\u20132026 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a><\/p><p>Candidate voltage-drop arithmetic only; not cable sizing or installation approval. Scientific review: July 2026.<\/p><\/footer><\/div>\r\n<script>(function(){'use strict';function $(i){return document.getElementById(i)}function p(raw,zero){var s=String(raw).trim().replace(\/\\s+\/g,'');if(!\/^[+]?(?:\\d+(?:[.,]\\d*)?|[.,]\\d+)$\/.test(s))return NaN;var n=Number(s.replace(',','.'));return Number.isFinite(n)&&(zero?n>=0:n>0)?n:NaN}function f(n){return n.toFixed(6).replace(\/(\\.\\d*?)0+$\/,'$1').replace(\/\\.$\/,'')}function tol(a,b){return Number.EPSILON*32*Math.max(1,Math.abs(a),Math.abs(b))}function calc(){var sys=$('vc-system').value,I=p($('vc-current').value),L=p($('vc-length').value),U=p($('vc-voltage').value),R=p($('vc-resistance').value),limit=p($('vc-limit').value);if(![I,L,U,R,limit].every(Number.isFinite)||limit>100){$('vc-results').classList.remove('vc-visible');return}var X=0,pf=1;if(sys!=='dc'){X=p($('vc-reactance').value,true);pf=p($('vc-pf').value);if(![X,pf].every(Number.isFinite)||pf>1){$('vc-results').classList.remove('vc-visible');return}}var sin=Math.sqrt(Math.max(0,1-pf*pf)),term=R*pf+X*sin,k=sys==='ac3'?Math.sqrt(3):2,drop=k*I*L*term\/1000,pct=100*drop\/U,ncond=sys==='ac3'?3:2,loss=ncond*I*I*R*L\/1000,ok=pct<=limit+tol(pct,limit);$('vc-r-check').innerHTML='<span style=\"color:var(--vc-'+(ok?'green':'red')+')\">'+(ok?'\u0394U% \u2264 entered limit':'\u0394U% > entered limit')+'<\/span>';$('vc-r-drop').innerHTML=f(drop)+' <span class=\"vc-rcard-unit\">V<\/span>';$('vc-r-pct').innerHTML=f(pct)+' <span class=\"vc-rcard-unit\">%<\/span>';$('vc-r-term').innerHTML=f(term)+' <span class=\"vc-rcard-unit\">\u03a9\/km<\/span>';$('vc-r-loss').innerHTML=f(loss)+' <span class=\"vc-rcard-unit\">W<\/span>';$('vc-r-note').textContent=(sys==='dc'?'Two-wire DC resistive model.':sys==='ac1'?'Single-phase, two-conductor, sinusoidal lagging-PF model.':'Balanced three-phase, sinusoidal lagging-PF model.')+' Passing the entered voltage-drop limit is not cable approval.';$('vc-results').classList.add('vc-visible');var u=new URL(location);u.searchParams.set('circuit_type',sys);u.searchParams.set('current_a',I);u.searchParams.set('one_way_length_m',L);u.searchParams.set('reference_voltage_v',U);u.searchParams.set('operating_resistance_ohm_per_km',R);u.searchParams.set('entered_drop_limit_pct',limit);['reactance_ohm_per_km','lagging_power_factor'].forEach(function(k){u.searchParams.delete(k)});if(sys!=='dc'){u.searchParams.set('reactance_ohm_per_km',X);u.searchParams.set('lagging_power_factor',pf)}history.replaceState(null,'',u.toString())}function mode(){var ac=$('vc-system').value!=='dc';document.querySelectorAll('.vc-ac-field').forEach(function(x){x.style.display=ac?'':'none'});calc()}$('vc-system').addEventListener('change',mode);$('vc-form').addEventListener('input',calc);$('vc-form').addEventListener('change',calc);$('vc-copy-btn').addEventListener('click',function(){if(navigator.clipboard)navigator.clipboard.writeText($('vc-results').innerText)});document.querySelectorAll('.vc-section-toggle').forEach(function(b){b.addEventListener('click',function(){var s=this.closest('.vc-section');s.classList.toggle('vc-open');this.setAttribute('aria-expanded',s.classList.contains('vc-open'))})});var q=[['Does IEC 60228 select cable size?','No. It standardizes conductor sizes and resistance\/construction requirements; 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