{"id":20631,"date":"2026-11-02T10:09:41","date_gmt":"2026-11-02T02:09:41","guid":{"rendered":"https:\/\/www.wehopower.com\/news\/power-supply-leakage-current-touch-current-method\/"},"modified":"2026-11-02T10:09:41","modified_gmt":"2026-11-02T02:09:41","slug":"power-supply-leakage-current-touch-current-method","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/","title":{"rendered":"Power Supply Leakage Current: Name the Path Before Comparing mA"},"content":{"rendered":"<div class=\"weho-blog-content\">\n<p><strong>Before comparing power supply leakage current, identify the current path, measurement network, operating condition and applicable product requirement.<\/strong> Protective-conductor current, touch current and the current measured during an insulation test are different records. A value from one cannot be used as the acceptance limit or test result for another.<\/p>\n<details class=\"article-toc\" open>\n<summary>On this page<\/summary>\n<ol class=\"toc-list\">\n<li><a href=\"#name-current\">Replace the ambiguous field name with a defined measurement<\/a><\/li>\n<li><a href=\"#paths-network\">Keep the path and the measuring network together<\/a><\/li>\n<li><a href=\"#operating-state\">Freeze the configuration behind the reading<\/a><\/li>\n<li><a href=\"#hdr150-measurement-identity\">Identify the HDR-150-24 configuration before choosing the method<\/a><\/li>\n<li><a href=\"#report-disposition\">Decide whether the returned evidence answers the requirement<\/a><\/li>\n<li><a href=\"#leakage-rfq\">Send a measurement-specific enquiry<\/a><\/li>\n<li><a href=\"#leakage-faq\">Two questions to close the review<\/a><\/li>\n<li><a href=\"#references\">Technical references<\/a><\/li>\n<\/ol>\n<\/details>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">M\u1ee5c l\u1ee5c<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Chuy\u1ec3n \u0111\u1ed5i<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/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=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Replace_the_ambiguous_field_name_with_a_defined_measurement\" >Replace the ambiguous field name with a defined measurement<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Keep_the_path_and_the_measuring_network_together\" >Keep the path and the measuring network together<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Freeze_the_configuration_behind_the_reading\" >Freeze the configuration behind the reading<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Identify_the_HDR-150-24_configuration_before_choosing_the_method\" >Identify the HDR-150-24 configuration before choosing the method<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Decide_whether_the_returned_evidence_answers_the_requirement\" >Decide whether the returned evidence answers the requirement<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Send_a_measurement-specific_enquiry\" >Send a measurement-specific enquiry<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Two_questions_to_close_the_review\" >Two questions to close the review<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Does_a_high_isolation_withstand_voltage_prove_low_touch_current\" >Does a high isolation withstand voltage prove low touch current?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Can_one_leakage-current_limit_be_used_for_every_industrial_product\" >Can one leakage-current limit be used for every industrial product?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.wehopower.com\/vi\/news\/power-supply-leakage-current-touch-current-method\/#Technical_references\" >Technical references<\/a><\/li><\/ul><\/nav><\/div>\n<h2 id=\"name-current\"><span class=\"ez-toc-section\" id=\"Replace_the_ambiguous_field_name_with_a_defined_measurement\"><\/span>Replace the ambiguous field name with a defined measurement<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A sourcing sheet headed only \u201cleakage: mA\u201d omits the information needed to interpret the number. Is it current in protective earth during normal operation, current through a body-impedance network connected to an accessible part, or an instrument reading during a dielectric test? Name the quantity and the equipment boundary before discussing whether the value is low enough.<\/p>\n<p><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/24992\" target=\"_blank\" rel=\"noopener\">IEC 60990<\/a> defines methods for touch-current and protective-conductor-current measurements. Its published scope explicitly does not specify the limit values. The applicable product standard and equipment classification must supply the acceptance basis. Do not turn a measurement-method reference into a universal current limit.<\/p>\n<figure class=\"article-relation concept-diagram\" id=\"figure-current-records\"><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/84-current-records.svg\" aria-label=\"Open full-size Different questions require different current records diagram\"><picture><source media=\"(max-width:640px)\" srcset=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/84-current-records-mobile.svg\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/84-current-records.svg\" width=\"1200\" height=\"548\" alt=\"Power Supply Leakage Current: Name the Path Before Comparing mA  title=\" power supply leakage current: name the path before comparing ma title =\"\"><\/picture><\/a><figcaption>Different questions require different current records. Concept illustration of separate review records; no measured result or WEHO qualification is shown.<\/figcaption><a class=\"diagram-original\" href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/84-current-records.svg\">Open full-size diagram<\/a><\/figure>\n<h2 id=\"paths-network\"><span class=\"ez-toc-section\" id=\"Keep_the_path_and_the_measuring_network_together\"><\/span>Keep the path and the measuring network together<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/www.us.lambda.tdk.com\/resources\/blogs\/20100802.html\" target=\"_blank\" rel=\"noopener\">TDK-Lambda\u2019s explanation of IEC 60990 testing<\/a> distinguishes protective-conductor current from touch current evaluated through a body-impedance network. The network matters because the test concerns a defined human-contact response rather than any arbitrary meter connected to an output or enclosure. Its historical standard references do not replace the current product-specific assessment.<\/p>\n<p>c\u00e1c <a href=\"https:\/\/www.xppower.com\/portals\/0\/brochures\/Essential_Guide_to_Power_Supplies.pdf\" target=\"_blank\" rel=\"noopener\">XP Power guide<\/a> identifies EMC filter Y capacitors as a contributor to earth current. That helps explain why insulation can be intact while an AC current still exists through a capacitive path. It does not prove the cause or magnitude of a reading on an unknown assembly, nor does it establish an acceptable value for that assembly.<\/p>\n<div class=\"weho-table-wrap\" tabindex=\"0\" role=\"region\" aria-label=\"Scrollable article table\">\n<table>\n<caption>Separate current records before making a compliance comparison<\/caption>\n<thead>\n<tr>\n<th scope=\"col\">Record<\/th>\n<th scope=\"col\">Path or condition to identify<\/th>\n<th scope=\"col\">Do not substitute<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Protective-conductor current<\/td>\n<td>Current in the defined PE path at stated operating conditions<\/td>\n<td>A touch-network result or a hipot reading<\/td>\n<\/tr>\n<tr>\n<td>Touch current<\/td>\n<td>Accessible point, prescribed measuring network and test condition<\/td>\n<td>An ordinary ammeter value without the specified network<\/td>\n<\/tr>\n<tr>\n<td>Dielectric-test current<\/td>\n<td>Defined test voltage, connections, duration and instrument rule<\/td>\n<td>Normal-operation leakage compliance<\/td>\n<\/tr>\n<tr>\n<td>\u0110i\u1ec7n tr\u1edf c\u00e1ch \u0111i\u1ec7n<\/td>\n<td>Specified DC test and resistance result<\/td>\n<td>A touch-current result<\/td>\n<\/tr>\n<tr>\n<td>System residual current<\/td>\n<td>Defined monitored branch and operating state<\/td>\n<td>The component\u2019s individual touch-current evidence<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2 id=\"operating-state\"><span class=\"ez-toc-section\" id=\"Freeze_the_configuration_behind_the_reading\"><\/span>Freeze the configuration behind the reading<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Retain exact model\/revision, input voltage and frequency, operating\/load state, accessible point or protective-conductor path, test equipment and method revision. Where the applicable plan includes supply polarity, normal and specified fault conditions, preserve those states separately. The test owner should define the required setup and safe execution; this article is not a mains-test connection procedure.<\/p>\n<p>Include connected interfaces in the system definition. A cable shield, grounded load, communication interface or external filter can change the available path. A component test with one arrangement does not automatically describe a final assembly with another. Record the actual configuration so the safety reviewer can determine which evidence remains applicable.<\/p>\n<p>Do not lift protective earth or alter protective connections as an informal way to obtain a preferred value. Any abnormal or fault-condition assessment belongs within an authorized test procedure. An unexplained difference between two readings should trigger a configuration and method review before it is called a product defect.<\/p>\n<h2 id=\"hdr150-measurement-identity\"><span class=\"ez-toc-section\" id=\"Identify_the_HDR-150-24_configuration_before_choosing_the_method\"><\/span>Identify the HDR-150-24 configuration before choosing the method<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>c\u00e1c <a href=\"https:\/\/www.wehopower.com\/vi\/product\/silm-size-hdr-150-150w-din-rail-switching-power-supply\/\">WEHO HDR-150-24 product details<\/a> V\u00e0 <a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2025\/07\/HDR-1502.pdf\">HDR-150 manufacturer specification<\/a> identify a concrete DIN-rail candidate. Match the pictured full model and N\/L input markings to the applicable document revision and the sample under assessment.<\/p>\n<figure class=\"product-reference product-scene\" id=\"figure-hdr150-current-identity\"><a class=\"product-image scene-product-image\" href=\"https:\/\/www.wehopower.com\/vi\/product\/silm-size-hdr-150-150w-din-rail-switching-power-supply\/\" aria-label=\"HDR-150-24 product details\"><img loading=\"lazy\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/84-hdr150-current-identity-scene-edge-v7.jpg\" width=\"1254\" height=\"1254\" alt=\"Power Supply Leakage Current: Name the Path Before Comparing mA  title=\" decoding=\"async\" power supply leakage current: name the path before comparing ma title =\"\"><\/a><figcaption>Application illustration; exact original product photograph retained, environment AI-assisted, not a customer installation or test. HDR-150-24 is shown in an assembly-preparation context. The illustration does not establish a leakage-current path or measurement result.<\/figcaption><div class=\"image-actions\"><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/84-hdr150-current-identity-original.jpg\">View unchanged original product photograph<\/a><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/84-hdr150-current-identity-scene-edge-v7.jpg\">View full-size application illustration<\/a><a href=\"https:\/\/www.wehopower.com\/vi\/product\/silm-size-hdr-150-150w-din-rail-switching-power-supply\/\">HDR-150-24 product details<\/a><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/84-hdr150-current-identity-scene-edge-v7-layers.svg\">Inspect illustration layers (SVG)<\/a><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2025\/07\/HDR-1502.pdf\">HDR-150-24 documentation<\/a><\/div>\n<\/figure>\n<p>Record the sample\u2019s input arrangement, DC load, accessible points, connected interfaces and host equipment. The plastic housing and the pictured terminal arrangement do not establish a safety class. Nor can the presence or absence of an external protective-earth terminal select the current measurement or its acceptance limit.<\/p>\n<p>Have the reviewer distinguish the required touch-current assessment from protective-conductor-current measurements applicable to an equipment PE path. Define that path at the correct component or equipment boundary; do not invent a PE measurement point on this sample. The applicable product assessment and documented method determine the setup.<\/p>\n<p>The HDR-150 sheet\u2019s withstand-voltage and insulation-resistance fields retain their own meanings. They do not constitute operating touch-current results. Request the applicable current evidence, measurement network, operating conditions and requirement for the ordered revision and final equipment configuration.<\/p>\n<h2 id=\"report-disposition\"><span class=\"ez-toc-section\" id=\"Decide_whether_the_returned_evidence_answers_the_requirement\"><\/span>Decide whether the returned evidence answers the requirement<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Start the review with the product requirement, then match the reported quantity, method, configuration and result to it. A useful report includes the applicable document revision, identified sample and a clear pass\/fail or measured-value record. If the method is incomplete or the current path is unnamed, hold the comparison rather than assuming that a smaller numerical value is better evidence.<\/p>\n<p>If the component and final-system configurations differ, identify the additional assessment needed. A design change may affect an interface or current path without changing the power supply itself. Keep that review linked to the system drawing and explain which test evidence is being retained, replaced or supplemented.<\/p>\n<p>This differs from an RCD nuisance-trip investigation. WEHO\u2019s separate multiple-SMPS leakage-budget article addresses a monitored branch and its equipment population. A branch observation can support that investigation; it cannot stand in for an individual equipment touch-current result or select a universal safety limit.<\/p>\n<h2 id=\"leakage-rfq\"><span class=\"ez-toc-section\" id=\"Send_a_measurement-specific_enquiry\"><\/span>Send a measurement-specific enquiry<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/www.wehopower.com\/vi\/contact\/\">Ask WEHO for model-specific current evidence<\/a> with the exact candidate, intended equipment category, input conditions, connected interfaces and the quantity your reviewer must assess. Request the method, conditions, applicable requirement and document revision with any stated value. Keep unresolved system-level testing visible before releasing the design.<\/p>\n<h2 id=\"leakage-faq\"><span class=\"ez-toc-section\" id=\"Two_questions_to_close_the_review\"><\/span>Two questions to close the review<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Does_a_high_isolation_withstand_voltage_prove_low_touch_current\"><\/span>Does a high isolation withstand voltage prove low touch current?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. An insulation withstand test and an operating touch-current measurement have different purposes and methods. Obtain the evidence required for each.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Can_one_leakage-current_limit_be_used_for_every_industrial_product\"><\/span>Can one leakage-current limit be used for every industrial product?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. Establish the applicable product requirements and measurement conditions for the equipment under review. A method standard alone does not supply a universal pass limit.<\/p>\n<section class=\"technical-references\">\n<h2 id=\"references\"><span class=\"ez-toc-section\" id=\"Technical_references\"><\/span>Technical references<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ul>\n<li><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/24992\" target=\"_blank\" rel=\"noopener\">IEC 60990 methods publication<\/a><\/li>\n<li><a href=\"https:\/\/www.us.lambda.tdk.com\/resources\/blogs\/20100802.html\" target=\"_blank\" rel=\"noopener\">TDK-Lambda leakage-current testing note<\/a><\/li>\n<li><a href=\"https:\/\/www.xppower.com\/portals\/0\/brochures\/Essential_Guide_to_Power_Supplies.pdf\" target=\"_blank\" rel=\"noopener\">XP Power Essential Guide to Power Supplies<\/a><\/li>\n<li><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2025\/07\/HDR-1502.pdf\">WEHO HDR-150 manufacturer specification<\/a><\/li>\n<\/ul>\n<\/section>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Separate power supply leakage current, touch current, protective-conductor current and hipot results with a measurement-specific OEM review checklist.<\/p>","protected":false},"author":2,"featured_media":20608,"parent":0,"menu_order":3,"comment_status":"","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[284],"class_list":["post-20631","news","type-news","status-publish","format-standard","has-post-thumbnail","hentry","news_category-product-articles","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/news\/20631","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/comments?post=20631"}],"version-history":[{"count":0,"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/news\/20631\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/media\/20608"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/media?parent=20631"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/vi\/wp-json\/wp\/v2\/news_category?post=20631"}],"curies":[{"name":"wp c\u1ee7a t\u00f4i","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}