{"id":1806,"date":"2026-07-27T10:32:50","date_gmt":"2026-07-27T02:32:50","guid":{"rendered":"https:\/\/jutrion.com\/?page_id=1806"},"modified":"2026-07-27T21:44:57","modified_gmt":"2026-07-27T13:44:57","slug":"%d0%ba%d0%b0%d0%bb%d1%8c%d0%ba%d1%83%d0%bb%d1%8f%d1%82%d0%be%d1%80-%d0%bf%d0%b0%d0%b4%d0%b5%d0%bd%d0%b8%d1%8f-%d0%bd%d0%b0%d0%bf%d1%80%d1%8f%d0%b6%d0%b5%d0%bd%d0%b8%d1%8f-%d0%b2-%d0%ba%d0%b0%d0%b1","status":"publish","type":"page","link":"https:\/\/jutrion.com\/ru\/tools\/cable-voltage-drop-calculator\/","title":{"rendered":"\u041a\u0430\u043b\u044c\u043a\u0443\u043b\u044f\u0442\u043e\u0440 \u043f\u0430\u0434\u0435\u043d\u0438\u044f \u043d\u0430\u043f\u0440\u044f\u0436\u0435\u043d\u0438\u044f \u0432 \u043a\u0430\u0431\u0435\u043b\u0435"},"content":{"rendered":"\n<!-- ===== JUTRION Cable Voltage Drop Calculator \u2014 paste into a WordPress \"Custom HTML\" block ===== -->\n<div class=\"jt-calc\">\n  <p class=\"eyebrow\">Power distribution<\/p>\n  <h1>Cable Voltage Drop Calculator (Cu &amp; Al)<\/h1>\n  <p class=\"tool-lede\">Estimate conductor voltage drop and percentage loss for DC, single-phase, and three-phase circuits from the current, run length, cross-section, and material, and compare it with the usual 3 % \/ 5 % limits. A resistance-based estimate \u2014 for long or heavily loaded cables, add the reactance term from the cable data.<\/p>\n\n  <div class=\"jt-card\"><div class=\"jt-grid\">\n    <div class=\"jt-inputs\">\n      <div class=\"jt-field\"><label>System<\/label>\n        <div class=\"jt-seg\" id=\"jt-sys\"><button type=\"button\" data-s=\"3\" aria-pressed=\"true\">3-phase<\/button><button type=\"button\" data-s=\"1\" aria-pressed=\"false\">1-phase<\/button><button type=\"button\" data-s=\"dc\" aria-pressed=\"false\">DC<\/button><\/div>\n      <\/div>\n      <div class=\"jt-two\">\n        <div class=\"jt-field\"><label for=\"jt-i\">Load current (A)<\/label><input type=\"number\" id=\"jt-i\" value=\"40\" min=\"0.1\" step=\"0.1\" inputmode=\"decimal\"><\/div>\n        <div class=\"jt-field\"><label for=\"jt-v\">Voltage (V)<\/label><input type=\"number\" id=\"jt-v\" value=\"400\" min=\"1\" step=\"1\" inputmode=\"numeric\"><\/div>\n      <\/div>\n      <div class=\"jt-two\">\n        <div class=\"jt-field\"><label for=\"jt-len\">One-way length (m)<\/label><input type=\"number\" id=\"jt-len\" value=\"50\" min=\"0.1\" step=\"0.5\" inputmode=\"decimal\"><\/div>\n        <div class=\"jt-field\"><label for=\"jt-cs\">Cross-section (mm\u00b2)<\/label><input type=\"number\" id=\"jt-cs\" value=\"10\" min=\"0.5\" step=\"0.5\" inputmode=\"decimal\"><\/div>\n      <\/div>\n      <div class=\"jt-two\">\n        <div class=\"jt-field\"><label for=\"jt-mat\">Conductor<\/label>\n          <select id=\"jt-mat\"><option value=\"cu\" selected>Copper<\/option><option value=\"al\">Aluminium<\/option><\/select>\n        <\/div>\n        <div class=\"jt-field\"><label for=\"jt-lim\">Allowed drop<\/label>\n          <select id=\"jt-lim\"><option value=\"5\" selected>5 % (power)<\/option><option value=\"3\">3 % (lighting)<\/option><option value=\"4\">4 %<\/option><\/select>\n        <\/div>\n      <\/div>\n    <\/div>\n    <div class=\"jt-readout\">\n      <div><div class=\"jt-rl\">Voltage drop<\/div><div class=\"jt-big\"><span id=\"jt-dv\">\u2014<\/span> <span>V<\/span><\/div><\/div>\n      <div class=\"jt-rec row\"><div class=\"k\">Percentage drop<\/div><div class=\"v\" id=\"jt-pct\">\u2014<\/div><\/div>\n      <div class=\"jt-rec row\"><div class=\"k\">Voltage at load<\/div><div class=\"v\" id=\"jt-end\">\u2014<\/div><\/div>\n      <div class=\"jt-rec\"><div class=\"k\">Against limit<\/div><div style=\"margin-top:6px\"><span class=\"jt-pill na\" id=\"jt-chk\">\u2014<\/span><\/div><\/div>\n      <button type=\"button\" class=\"jt-copy\" id=\"jt-copy\">Copy result<\/button>\n    <\/div>\n  <\/div><\/div>\n\n  <div class=\"jt-content\">\n    <h2>How it is calculated<\/h2>\n    <p>The conductor resistance for a one-way length is R = \u03c1 \u00d7 L \/ S, and the number of loaded conductors sets the multiplier:<\/p>\n    <div class=\"jt-eq\">Three-phase: \u0394V = \u221a3 \u00d7 I \u00d7 \u03c1 \u00d7 L \/ S\nSingle-phase\/DC: \u0394V = 2 \u00d7 I \u00d7 \u03c1 \u00d7 L \/ S\nPercentage: \u0394V% = \u0394V \/ V \u00d7 100<\/div>\n    <p>where <b>I<\/b> is current (A), <b>L<\/b> the one-way run (m), <b>S<\/b> the cross-section (mm\u00b2), and <b>\u03c1<\/b> the resistivity at operating temperature \u2014 about <b>0.0225<\/b> \u03a9\u00b7mm\u00b2\/m for copper and <b>0.036<\/b> for aluminium (roughly 70 \u00b0C). Single-phase and DC use a factor of 2 for the go-and-return conductors; three-phase uses \u221a3 on the line-to-line voltage.<\/p>\n    <div class=\"jt-note\"><span>\u24d8<\/span><span>This estimate uses resistance only. For large cross-sections and long runs the inductive reactance adds to the drop \u2014 include the cable&#8217;s X and the load power factor (\u0394V = I(R cos \u03c6 + X sin \u03c6)) for a rigorous figure.<\/span><\/div>\n\n    <h2>Typical limits<\/h2>\n    <p>Common design limits are about <b>3 %<\/b> for lighting and <b>5 %<\/b> for other uses, measured from the origin of the installation to the load. Excessive drop dims lighting, weakens motor torque on start, and wastes energy as heat. If the drop is too high, increase the cross-section, shorten the run, or raise the distribution voltage \u2014 do not simply accept it.<\/p>\n\n    <h2>Frequently asked questions<\/h2>\n    <div class=\"jt-faq\">\n      <details><summary>Do I use one-way or round-trip length?<\/summary><p>Enter the one-way route length. The formula already applies the factor of 2 for single-phase and DC, and \u221a3 for three-phase, so the return path is accounted for.<\/p><\/details>\n      <details><summary>Why does aluminium drop more than copper?<\/summary><p>Aluminium has about 60 % higher resistivity, so for the same size and current it drops more. It is often sized one or two steps larger than copper to reach the same performance.<\/p><\/details>\n      <details><summary>Is the drop worse on motor starting?<\/summary><p>Yes. Starting current is several times the running current, so the momentary drop is much larger and can prevent the motor developing enough torque \u2014 check the starting condition separately.<\/p><\/details>\n    <\/div>\n\n    <div class=\"jt-cta\">\n      <h2>Protect and switch the circuit<\/h2>\n      <p>With the conductor sized for voltage drop, confirm the breaker and its coordination for the same cable.<\/p>\n      <div class=\"jt-cta-btns\">\n        <a class=\"jt-btn\" href=\"https:\/\/jutrion.com\/products\/\">Browse JUTRION products<\/a>\n        <a class=\"jt-btn ghost\" href=\"https:\/\/jutrion.com\/contact\/\">Get a free quote<\/a>\n      <\/div>\n      <p class=\"jt-related\">Related products: <a href=\"https:\/\/jutrion.com\/mccb\/\">MCCB<\/a> \u00b7 <a href=\"https:\/\/jutrion.com\/mcb\/\">MCB<\/a> \u00b7 <a href=\"https:\/\/jutrion.com\/isolator-switch\/\">Isolator switch<\/a><\/p>\n    <\/div>\n\n    <div class=\"jt-std\"><strong>Standards referenced<\/strong>IEC 60364-5-52 (wiring systems, voltage drop guidance) \u00b7 conductor resistivity at operating temperature.<\/div>\n    <p class=\"jt-fine\">Resistance-based estimate for guidance only. Final conductor sizing must account for reactance, power factor, temperature, installation method, and the applicable wiring rules, verified by a qualified person.<\/p>\n  <\/div>\n<\/div>\n\n<script>\n(function(){\n  var $=function(id){return document.getElementById(id);};\n  var i=$('jt-i'),v=$('jt-v'),len=$('jt-len'),cs=$('jt-cs'),mat=$('jt-mat'),lim=$('jt-lim'),\n      dvEl=$('jt-dv'),pctEl=$('jt-pct'),endEl=$('jt-end'),chk=$('jt-chk');\n  var sys='3', RHO={cu:0.0225,al:0.036};\n  document.querySelectorAll('#jt-sys button').forEach(function(b){b.addEventListener('click',function(){sys=b.dataset.s;document.querySelectorAll('#jt-sys button').forEach(function(x){x.setAttribute('aria-pressed',x===b?'true':'false');});if(sys==='1'&&v.value==='400')v.value='230';if(sys==='dc'&&v.value==='400')v.value='220';if(sys==='3'&&(v.value==='230'||v.value==='220'))v.value='400';calc();});});\n  function calc(){\n    var I=parseFloat(i.value),V=parseFloat(v.value),L=parseFloat(len.value),S=parseFloat(cs.value),rho=RHO[mat.value];\n    if(!(I>0&&V>0&&L>0&&S>0)){dvEl.textContent='\u2014';pctEl.textContent=endEl.textContent='\u2014';chk.className='jt-pill na';chk.textContent='\u2014';return;}\n    var k=(sys==='3')?Math.sqrt(3):2;\n    var dv=k*I*rho*L\/S;\n    var pct=dv\/V*100;\n    dvEl.textContent=dv.toFixed(2);\n    pctEl.textContent=pct.toFixed(2)+' %';\n    endEl.textContent=(V-dv).toFixed(1)+' V';\n    var lm=parseFloat(lim.value);var pass=pct<=lm;\n    chk.className='jt-pill '+(pass?'ok':'no');\n    chk.textContent=pass?('PASS \u2014 '+pct.toFixed(1)+'% \u2264 '+lm+'%'):('EXCEEDS '+lm+'% \u2014 increase mm\u00b2');\n  }\n  [i,v,len,cs,mat,lim].forEach(function(el){el.addEventListener('input',calc);el.addEventListener('change',calc);});\n  $('jt-copy').addEventListener('click',function(){var b=$('jt-copy');var txt='System: '+(sys==='dc'?'DC':sys+'-phase')+', '+i.value+' A, '+len.value+' m, '+cs.value+' mm\u00b2 '+mat.value.toUpperCase()+'\\nVoltage drop: '+dvEl.textContent+' V ('+pctEl.textContent+')\\nVoltage at load: '+endEl.textContent+'\\nCheck: '+chk.textContent;navigator.clipboard.writeText(txt).then(function(){var o=b.textContent;b.textContent='Copied \u2713';setTimeout(function(){b.textContent=o;},1500);}).catch(function(){b.textContent='Press Ctrl+C';});});\n  calc();\n})();\n<\/script>\n<!-- ===== end block ===== -->\n\n","protected":false},"excerpt":{"rendered":"<p>Power distribution Cable Voltage Drop Calculator (Cu &amp; Al) Estimate conductor voltage drop and percentage loss for DC, single-phase, and three-phase circuits from the current, run length, cross-section, and material, and compare it with the usual 3 % \/ 5 % limits. A resistance-based estimate \u2014 for long or heavily loaded cables, add the reactance [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1778,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1806","page","type-page","status-publish","hentry"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/pages\/1806","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/comments?post=1806"}],"version-history":[{"count":2,"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/pages\/1806\/revisions"}],"predecessor-version":[{"id":1835,"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/pages\/1806\/revisions\/1835"}],"up":[{"embeddable":true,"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/pages\/1778"}],"wp:attachment":[{"href":"https:\/\/jutrion.com\/ru\/wp-json\/wp\/v2\/media?parent=1806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}