{"id":19977,"date":"2026-10-23T16:45:29","date_gmt":"2026-10-23T08:45:29","guid":{"rendered":"https:\/\/www.wehopower.com\/news\/eft-test-power-supply-system-acceptance\/"},"modified":"2026-10-23T16:45:29","modified_gmt":"2026-10-23T08:45:29","slug":"eft-test-power-supply-system-acceptance","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/bn\/news\/eft-test-power-supply-system-acceptance\/","title":{"rendered":"EFT Test Planning for Power Supplies: Ports, Recovery, and System Evidence"},"content":{"rendered":"<div class=\"weho-blog-content\" id=\"weho-article-33\" data-weho-article-id=\"33\">\n<p>\u0986 <strong>EFT test<\/strong> evaluates equipment immunity to repetitive electrical fast transients, also called burst disturbances. For an OEM integrating a power supply, a useful test plan covers the equipment&#8217;s relevant ports and operating modes, then records what the powered functions do during and after exposure.<\/p>\n<p><strong>Define acceptable system behavior before testing.<\/strong> A steady power-supply indicator does not show whether the controller reset, communications stopped, or a stored setting changed. The integration engineer&#8217;s decision is whether the specified assembly meets its agreed functional requirements in the documented test configuration.<\/p>\n<details class=\"article-toc\" open=\"\">\n<summary>Article sections<\/summary>\n<nav class=\"toc-links\" aria-label=\"Article sections\"><a href=\"#separate-the-disturbance-from-the-acceptance-decision\">Separate the disturbance from the acceptance decision<\/a><a href=\"#freeze-the-assembly-and-its-port-map\">Freeze the assembly and its port map<\/a><a href=\"#ndr-eft-configuration-review\">Identify NDR-240-24 within the EFT configuration<\/a><a href=\"#write-observable-functional-criteria\">Write observable functional criteria<\/a><a href=\"#use-a-correlated-event-record\">Use a correlated event record<\/a><a href=\"#example-a-cable-port-disturbance-leaves-stale-process-data\">Example: a cable-port disturbance leaves stale process data<\/a><a href=\"#review-supplier-evidence-and-the-system-report-separately\">Review supplier evidence and the system report separately<\/a><\/nav>\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\">\u09b8\u09c2\u099a\u09bf\u09aa\u09a4\u09cd\u09b0<\/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;\">\u099f\u0997\u09b2 \u0995\u09b0\u09c1\u09a8<\/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\/bn\/news\/eft-test-power-supply-system-acceptance\/#Separate_the_disturbance_from_the_acceptance_decision\" >Separate the disturbance from the acceptance decision<\/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\/bn\/news\/eft-test-power-supply-system-acceptance\/#Freeze_the_assembly_and_its_port_map\" >Freeze the assembly and its port map<\/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\/bn\/news\/eft-test-power-supply-system-acceptance\/#Identify_NDR-240-24_within_the_EFT_configuration\" >Identify NDR-240-24 within the EFT configuration<\/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\/bn\/news\/eft-test-power-supply-system-acceptance\/#Write_observable_functional_criteria\" >Write observable functional criteria<\/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\/bn\/news\/eft-test-power-supply-system-acceptance\/#Use_a_correlated_event_record\" >Use a correlated event record<\/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\/bn\/news\/eft-test-power-supply-system-acceptance\/#Example_a_cable-port_disturbance_leaves_stale_process_data\" >Example: a cable-port disturbance leaves stale process data<\/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\/bn\/news\/eft-test-power-supply-system-acceptance\/#Review_supplier_evidence_and_the_system_report_separately\" >Review supplier evidence and the system report separately<\/a><\/li><\/ul><\/nav><\/div>\n<h2 id=\"separate-the-disturbance-from-the-acceptance-decision\"><span class=\"ez-toc-section\" id=\"Separate_the_disturbance_from_the_acceptance_decision\"><\/span>Separate the disturbance from the acceptance decision<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/22271\" target=\"_blank\" rel=\"noopener noreferrer\">IEC 61000-4-4:2012<\/a> provides a basic EMC reference for evaluating electrical fast-transient\/burst immunity at supply, signal, control, and earth ports. Record the edition required by the applicable product standard or contract. A standard number without its edition, test conditions, and outcome is an incomplete requirement.<\/p>\n<p>EFT is distinct from an <a href=\"https:\/\/www.wehopower.com\/bn\/news\/esd-testing-powered-equipment-validation\/\" data-weho-link-kind=\"guide\">equipment-level electrostatic-discharge test<\/a> or a surge test, as shown in <a href=\"https:\/\/www.ti.com\/document-viewer\/lit\/html\/SSZTBK1\/GUID-10FBF936-D300-4BE1-A835-B0496E7546C7\" target=\"_blank\" rel=\"noopener noreferrer\">TI&#8217;s overview of system transient standards<\/a>. A report for one phenomenon does not establish performance under the others. Keep the test matrix and findings separate, even when one laboratory performs all three in the same campaign.<\/p>\n<p>The appropriate severity, applicable ports, and performance criteria need to be established for the actual equipment and its governing requirements. This article proposes a planning and evidence structure; it does not assign a universal voltage, waveform program, exposure time, or pass criterion to every industrial power supply.<\/p>\n<h2 id=\"freeze-the-assembly-and-its-port-map\"><span class=\"ez-toc-section\" id=\"Freeze_the_assembly_and_its_port_map\"><\/span>Freeze the assembly and its port map<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Document the configuration being qualified: power-supply model and revision, input source, connected load, enclosure, grounding and bonding arrangement, filters, cable types and lengths, shield terminations, and firmware. If an auxiliary unit is needed, identify its role and how it is kept from obscuring the equipment&#8217;s behavior.<\/p>\n<p>Map physical interfaces before deciding which tests apply. An external DC input, an internally wired DC rail, and a long external sensor cable have different places in the equipment boundary. Have the laboratory and responsible EMC engineer agree the applicable treatment instead of selecting ports solely because a terminal is labeled \u201c24 V.\u201d<\/p>\n<div class=\"weho-table-wrap\" tabindex=\"0\" role=\"region\" aria-label=\"Engineering comparison table\">\n<table>\n<thead>\n<tr>\n<th scope=\"col\">Port or function<\/th>\n<th scope=\"col\">Planning information<\/th>\n<th scope=\"col\">Evidence to retain<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>AC or DC supply port<\/td>\n<td>Source, operating input, loading, protection, and applicable coupling method<\/td>\n<td>Port identity, test-program reference, setup photographs, and rail\/function observations<\/td>\n<\/tr>\n<tr>\n<td>External signal or control cable<\/td>\n<td>Interface use, representative cable, termination, shield, and active traffic<\/td>\n<td>Cable route, exposure arrangement, error counters, and application result<\/td>\n<\/tr>\n<tr>\n<td>Protective-earth and chassis connections<\/td>\n<td>Installed bonding arrangement and required reference-plane relationship<\/td>\n<td>Photographs and the controlled setup description<\/td>\n<\/tr>\n<tr>\n<td>Dependent powered function<\/td>\n<td>Controller, communication, display, or output state that matters to the application<\/td>\n<td>Monitoring method, behavior during exposure, and recovery outcome<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<figure class=\"article-relation\"><picture><source media=\"(max-width:600px)\" srcset=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/33-mobile.svg\"><img fetchpriority=\"high\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/33-desktop.svg\" width=\"1200\" height=\"675\" alt=\"EFT Test Planning for Power Supplies: Ports, Recovery, and System Evidence  title=\" loading=\"eager\" decoding=\"async\" eft test planning for power supplies: and system evidence title=\"\"><\/picture><figcaption>Original conceptual equipment-evidence map. Exposure ports and methods follow the applicable test plan; the graphic is not an EFT coupling setup or measured event log.<br \/>\n<a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/33-desktop.svg\" target=\"_blank\" rel=\"noopener\" class=\"diagram-original\" data-weho-link-role=\"view_original\">View full diagram \u2197<\/a><\/figcaption><\/figure>\n<p>Coupling and setup are part of the result. <a href=\"https:\/\/www.ametek-cts.com\/jpn-home\/transient-generator-tn0108\" target=\"_blank\" rel=\"noopener noreferrer\">AMETEK CTS&#8217;s burst-waveform verification note (Japanese)<\/a> explains that grounding affects the burst characteristics delivered to the equipment and separately discusses verification of the coupling network and capacitive clamp. Keep the actual coupling arrangement, grounding and reference-plane relationship, and relevant equipment-verification record with the test. A generator-front-panel photograph cannot capture those conditions for a repeat comparison.<\/p>\n<section class=\"weho-model-review\" aria-labelledby=\"ndr-eft-configuration-review\" data-weho-model=\"NDR-240-24\">\n<h2 id=\"ndr-eft-configuration-review\"><span class=\"ez-toc-section\" id=\"Identify_NDR-240-24_within_the_EFT_configuration\"><\/span>Identify NDR-240-24 within the EFT configuration<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"model-review-layout\">\n<div class=\"model-review-intro\">\n<p>If a proposed control cabinet uses the <a href=\"https:\/\/www.wehopower.com\/bn\/product\/ndr-dinrail-240w-ac-to-dc-single-output-switching-power-supply\/\" data-weho-link-kind=\"product_detail\">WEHO NDR-240-24 DIN rail supply<\/a> for its internal control rail, give that source a stable identifier in the equipment port map. The <a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2021\/11\/NDR-240.pdf\">NDR-240 specification<\/a> lists 24 V, 0\u201310 A output and an 85\u2013264 V AC input range. Use those as starting points for the electrical review, then confirm the conditions permitted for the actual input, load and installation. Retain the exact sample marking and applicable specification revision beside the upstream AC feed, downstream load distribution, chassis bonding, and external cable records.<\/p>\n<\/div>\n<figure class=\"model-photo\"><a href=\"https:\/\/www.wehopower.com\/bn\/product\/ndr-dinrail-240w-ac-to-dc-single-output-switching-power-supply\/\" class=\"model-product-link\" data-weho-link-role=\"product_image\" data-weho-model=\"NDR-240-24\" aria-label=\"NDR-240-24 product details\" data-weho-link-kind=\"product_detail\"><img loading=\"lazy\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/ndr-240-24.webp\" width=\"550\" height=\"880\" alt=\"EFT Test Planning for Power Supplies: Ports, Recovery, and System Evidence  title=\" decoding=\"async\" eft test planning for power supplies: and system evidence title =\"\"><\/a><figcaption><a href=\"https:\/\/www.wehopower.com\/bn\/product\/ndr-dinrail-240w-ac-to-dc-single-output-switching-power-supply\/\" class=\"model-name-link\" data-weho-link-role=\"product_text\" data-weho-link-kind=\"product_detail\">NDR-240-24 product details \u2197<\/a><br \/>\n<span>NDR-240-24 configuration reference; EFT results require a matching report and setup.<\/span><br \/>\n<a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/ndr-240-24-original-scaled.png\" target=\"_blank\" rel=\"noopener\" class=\"photo-original\" data-weho-link-role=\"view_original\">View original photograph \u2197<\/a><\/figcaption><\/figure>\n<div class=\"model-review-detail\">\n<p>Ask WEHO which model-specific EFT evidence is available and what assembly, ports, loading, edition, and performance criterion it covers. Give the laboratory the complete cabinet configuration so it can determine the remaining equipment assessment. A supply photograph identifies the proposed hardware; it neither reports an EFT pass nor establishes immunity of the external control cable in the hypothetical example below.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<h2 id=\"write-observable-functional-criteria\"><span class=\"ez-toc-section\" id=\"Write_observable_functional_criteria\"><\/span>Write observable functional criteria<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Translate \u201cno malfunction\u201d into conditions the test team can observe. List the critical functions, their normal states, allowed deviations where permitted by the governing requirements, and how recovery will be assessed. Assign a monitoring method to every important criterion.<\/p>\n<p>Record behavior during exposure as well as after it. An application may resume normally after a reset while having lost a command or interrupted a process. A post-test voltage reading cannot reveal that history. Likewise, the supply rail may remain within its required range while an external interface experiences errors.<\/p>\n<div class=\"weho-table-wrap\" tabindex=\"0\" role=\"region\" aria-label=\"Engineering comparison table\">\n<table>\n<thead>\n<tr>\n<th scope=\"col\">\u09ab\u09be\u0982\u09b6\u09a8<\/th>\n<th scope=\"col\">Observation to plan<\/th>\n<th scope=\"col\">Acceptance question<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Power delivery<\/td>\n<td>Relevant rail behavior at the supply and sensitive load, with the measurement method identified<\/td>\n<td>Did the required power condition remain satisfied?<\/td>\n<\/tr>\n<tr>\n<td>Controller operation<\/td>\n<td>Reset cause, restart count, watchdog indication, and task-state record<\/td>\n<td>Was a restart permitted, and was the required state preserved?<\/td>\n<\/tr>\n<tr>\n<td>Communications during the burst sequence<\/td>\n<td>Exposed cable-port ID, time-correlated retries or missing messages, stale-data interval, and application acknowledgment<\/td>\n<td>Did the interface meet its required continuity during exposure and recovery afterward?<\/td>\n<\/tr>\n<tr>\n<td>Commands and stored data<\/td>\n<td>Output state, settings, counters, and transaction integrity<\/td>\n<td>Was there an unintended action or unacceptable data change?<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>These are proposed observation categories, not a replacement for the applicable performance criterion. If that criterion requires uninterrupted operation, an automatically recovering reset is still relevant evidence against the requirement. If temporary degradation is permitted, define its boundaries without retroactively relaxing them after a failure.<\/p>\n<h2 id=\"use-a-correlated-event-record\"><span class=\"ez-toc-section\" id=\"Use_a_correlated_event_record\"><\/span>Use a correlated event record<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Plan a common timeline linking each exposure to system observations. Identify the test step, port, polarity, program, operating mode, and monitoring channels. Where feasible, retain a time-correlated rail capture, reset or event log, and communication result. State the resolution and limitations of each monitoring method.<\/p>\n<p>Keep monitoring from changing the tested configuration unnecessarily. Probes, instrument grounds, and additional communication leads can affect a system. Have the test team document their arrangement and explain any method used to observe the equipment without introducing an unintended connection.<\/p>\n<p>For baseline electrical measurements, the <a href=\"https:\/\/www.wehopower.com\/bn\/news\/power-supply-ripple-acceptance-test-matrix\/\" data-weho-link-kind=\"guide\">power-supply ripple acceptance guide<\/a> helps define measurement conditions. Normal ripple acceptance and EFT immunity remain separate checks; passing either does not establish the other.<\/p>\n<h2 id=\"example-a-cable-port-disturbance-leaves-stale-process-data\"><span class=\"ez-toc-section\" id=\"Example_a_cable-port_disturbance_leaves_stale_process_data\"><\/span>Example: a cable-port disturbance leaves stale process data<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>In a hypothetical machine qualification, an EFT exposure is applied through the agreed coupling arrangement associated with an external control cable. The monitored supply rail stays within the project voltage envelope, but communication retries increase and the controller continues displaying a stale process value. The link returns to normal after the event. A note saying \u201csystem recovered\u201d would miss the stale-data interval and the route associated with the exposure.<\/p>\n<p>Compare the stale-data interval, its indication to the operator and any downstream action with the criteria agreed before testing. Retain the specific cable-port ID, coupling arrangement, cable routing, timestamps and protocol logs beside the rail record. Record a nonconformance where a required function was not maintained. An apparently stable rail does not establish that every relevant disturbance path was excluded, and the communication error alone does not identify the AC-DC supply as its cause.<\/p>\n<p>After an engineering change, identify exactly what changed and arrange the necessary repeat assessment. A new filter, cable route, shield connection, or firmware recovery behavior creates a new configuration record. Do not combine its passing outcome with the earlier setup as though nothing changed.<\/p>\n<h2 id=\"review-supplier-evidence-and-the-system-report-separately\"><span class=\"ez-toc-section\" id=\"Review_supplier_evidence_and_the_system_report_separately\"><\/span>Review supplier evidence and the system report separately<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A supplier&#8217;s power-supply test report can support candidate selection when the model, revision, ports, load, setup, standard edition, and performance criterion match the claim. It does not automatically cover the OEM&#8217;s enclosure, external interfaces, or firmware.<\/p>\n<p>The release record should therefore include the supplier evidence and the equipment-level findings, with their scopes stated. Use the <a href=\"https:\/\/www.wehopower.com\/bn\/news\/industrial-power-supply-replacement-interface-validation\/\" data-weho-link-kind=\"guide\">power-supply replacement checklist<\/a> when a later substitution may affect the qualified assembly.<\/p>\n<p><a href=\"https:\/\/www.wehopower.com\/bn\/contact\/\" data-weho-link-kind=\"inquiry\">Send WEHO your power-supply requirement and proposed EFT evidence matrix<\/a>, including the input source, load, relevant ports, installation, and required functional behavior. Ask which model-specific evidence is available, then agree the remaining equipment-level evaluation with your EMC engineer and laboratory.<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>A power supply surviving an EFT test does not show that the complete machine kept working. Define the tested ports, active functions, and recovery evidence before booking the laboratory.<\/p>","protected":false},"author":2,"featured_media":19916,"parent":0,"menu_order":69,"comment_status":"","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[284],"class_list":["post-19977","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\/bn\/wp-json\/wp\/v2\/news\/19977","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/comments?post=19977"}],"version-history":[{"count":0,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/news\/19977\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/media\/19916"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/media?parent=19977"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/bn\/wp-json\/wp\/v2\/news_category?post=19977"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}