{"id":19232,"date":"2026-10-17T11:11:17","date_gmt":"2026-10-17T03:11:17","guid":{"rendered":"https:\/\/www.wehopower.com\/news\/sizing-output-capacitance-mains-dip-ride-through\/"},"modified":"2026-10-19T12:08:13","modified_gmt":"2026-10-19T04:08:13","slug":"sizing-output-capacitance-mains-dip-ride-through","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/","title":{"rendered":"Sizing Output Capacitance for Mains Dip Ride-Through"},"content":{"rendered":"<article>\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\">Table des mati\u00e8res<\/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;\">Basculer<\/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-1'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.wehopower.com\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Sizing_Output_Capacitance_for_Mains_Dip_Ride-Through\" >Sizing Output Capacitance for Mains Dip Ride-Through<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.wehopower.com\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Write_the_ride-through_requirement_before_requesting_a_sample\" >Write the ride-through requirement before requesting a sample<\/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\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Estimate_the_storage_but_do_not_order_from_the_estimate_alone\" >Estimate the storage, but do not order from the estimate alone<\/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\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Confirm_charging_and_reverse-current_behavior\" >Confirm charging and reverse-current behavior<\/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\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Compare_a_capacitor_bank_with_a_qualified_buffer_module\" >Compare a capacitor bank with a qualified buffer module<\/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\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Make_the_sample_test_a_purchasing_acceptance_gate\" >Make the sample test a purchasing acceptance gate<\/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\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Buyer_questions\" >Buyer questions<\/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\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Can_the_specified_50_ms_simply_be_deducted_from_the_required_external_storage_time\" >Can the specified 50 ms simply be deducted from the required external storage time?<\/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\/fr\/news\/sizing-output-capacitance-mains-dip-ride-through\/#Is_a_larger_output_capacitor_always_a_better_purchasing_choice\" >Is a larger output capacitor always a better purchasing choice?<\/a><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h1><span class=\"ez-toc-section\" id=\"Sizing_Output_Capacitance_for_Mains_Dip_Ride-Through\"><\/span>Sizing Output Capacitance for Mains Dip Ride-Through<span class=\"ez-toc-section-end\"><\/span><\/h1>\n<figure data-image-role=\"application_a\"><img fetchpriority=\"high\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/01-application-a-85.png?quality=85&#038;strip=all\" alt=\"Sizing Output Capacitance for Mains Dip Ride-Through  title=\" width=\"1536\" height=\"1024\" sizing output capacitance for mains dip ride-through title=\"\"><figcaption>Mechanical integration stage for a protected controller compartment. The DR-30-12 terminal positions remain empty; this does not demonstrate buffer compatibility or ride-through.<\/figcaption><\/figure>\n<p>For an OEM controller that must survive a short mains interruption, output capacitance is an <strong>energy and interface requirement<\/strong>, not simply a larger capacitor value. Define the load that must remain alive, its minimum permissible voltage and the required duration; then qualify charging, reverse current, discharge safety and restart behavior with the power supply supplier.<\/p>\n<p>The WEHO DR-30-12 illustrates the boundary. Its exact 12 V version is marked 2 A, and its supplied sheet lists 50 ms hold-up at 230 VAC and full load. That conditional figure is not a guarantee at every input voltage, nor permission to connect an arbitrary external capacitor bank. The retained sheet does not state a maximum approved external output capacitance.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Write_the_ride-through_requirement_before_requesting_a_sample\"><\/span>Write the ride-through requirement before requesting a sample<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Separate essential logic from dispensable loads. Keeping an event logger alive may need far less stored energy than maintaining every relay, lamp and actuator on the same rail. State whether the objective is uninterrupted control, completion of one transaction, or an orderly shutdown. These require different durations and may need different safety behavior.<\/p>\n<table>\n<thead>\n<tr>\n<th>RFQ requirement<\/th>\n<th>Why the supplier needs it<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Essential load current or power during the dip<\/td>\n<td>Defines energy demand; include any final write or communication burst<\/td>\n<\/tr>\n<tr>\n<td>Highest starting voltage and lowest acceptable receiver voltage<\/td>\n<td>Defines usable capacitor energy after distribution and isolation losses<\/td>\n<\/tr>\n<tr>\n<td>Interruption duration and repeat interval<\/td>\n<td>Defines storage and recharge requirements<\/td>\n<\/tr>\n<tr>\n<td>Required restart and shutdown sequence<\/td>\n<td>Prevents an unstable partly powered controller state<\/td>\n<\/tr>\n<tr>\n<td>Temperature, space and service life target<\/td>\n<td>Defines component derating and the sample validation conditions<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><span class=\"ez-toc-section\" id=\"Estimate_the_storage_but_do_not_order_from_the_estimate_alone\"><\/span>Estimate the storage, but do not order from the estimate alone<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>For an ideal constant-current load, the first estimate is <strong>C = I \u00d7 t \/ (Vstart \u2212 Vmin)<\/strong>. Suppose a hypothetical receiver needs 0.5 A for 0.2 s while its capacitor voltage falls from 12 V to 10.5 V. The ideal requirement is about 0.067 F, or 67,000 \u00b5F. This is a design example, not an approved DR-30-12 accessory value.<\/p>\n<p>A constant-power load needs an energy calculation: <strong>C = 2 \u00d7 P \u00d7 t \/ (Vstart\u00b2 \u2212 Vmin\u00b2)<\/strong> for an ideal direct supply path. At an assumed 5 W for 0.2 s over the same voltage window, the result is about 0.059 F. Real designs must account for conversion loss where applicable, capacitor tolerance, ESR-related voltage drop, leakage, temperature and aging. Use the actual voltage available after any blocking element, not the power supply&#8217;s nominal label alone.<\/p>\n<p><a href=\"https:\/\/origin-www.us.lambda.tdk.com\/resources\/blogs\/20200415.html\" target=\"_blank\" rel=\"noopener\">The referenced discussion of hold-up energy storage<\/a> explains the stored-energy relationship and why the storage voltage matters. It is general guidance, not a compatibility statement for the WEHO unit. Do not open or modify the supply&#8217;s internal high-voltage bus to increase hold-up.<\/p>\n<figure data-image-role=\"product_detail\"><img decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/03-product-detail-80.png?quality=85&#038;strip=all\" alt=\"Sizing Output Capacitance for Mains Dip Ride-Through  title=\" width=\"1536\" height=\"1024\" sizing output capacitance for mains dip ride-through title=\"\"><figcaption>The original nameplate identifies the sample revision and nominal output. It does not state an approved external capacitance.<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Confirm_charging_and_reverse-current_behavior\"><\/span>Confirm charging and reverse-current behavior<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A large empty capacitor looks like a demanding load during startup. Ask for the allowable external capacitance or an approved charging arrangement, including current limiting and the available recharge current while the normal load is operating. A design that survives one dip but cannot recharge before the next one does not meet a repetitive interruption requirement.<\/p>\n<p>Also confirm whether stored energy can flow back into the supply or other branches after AC removal. Any isolation, discharge path and protection devices must be selected for the actual circuit. A capacitor remains an energy source after the mains disconnect opens; service instructions and verification points need to address that stored energy.<\/p>\n<figure data-image-role=\"application_b\"><img decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/02-application-b-81.png?quality=85&#038;strip=all\" alt=\"Sizing Output Capacitance for Mains Dip Ride-Through  title=\" width=\"1536\" height=\"1024\" sizing output capacitance for mains dip ride-through title=\"\"><figcaption>A separate laboratory-machine layout illustrates rail placement and terminal access before electrical termination. No hold-up test or operating result is implied.<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Compare_a_capacitor_bank_with_a_qualified_buffer_module\"><\/span>Compare a capacitor bank with a qualified buffer module<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>A discrete bank can be appropriate when the OEM controls the complete design and validation. A purpose-designed DC buffer may provide defined charging and power-path behavior, but it still needs the correct voltage, current, duration, temperature and interface evidence. Neither route becomes qualified merely because it can be mounted beside the DR-30-12 on a rail.<\/p>\n<p>The DR-30-12 is a protected-indoor DIN-rail supply. Its source label states 100\u2013240 VAC, 1.1 A, 50\/60 Hz and +12 V, 2 A. Obtain the offered revision and matching terminal instructions before the assembly drawing is released; do not infer a buffer connection from a generic series diagram or reuse another voltage variant&#8217;s rating.<\/p>\n<figure data-image-role=\"engineering_context\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/10\/04-engineering-context-84.png?quality=85&#038;strip=all\" alt=\"Sizing Output Capacitance for Mains Dip Ride-Through  title=\" width=\"1536\" height=\"1024\" sizing output capacitance for mains dip ride-through title=\"\"><figcaption>A purchasing specification must cover both stored energy and how the complete circuit charges, recovers and becomes safe to service.<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Make_the_sample_test_a_purchasing_acceptance_gate\"><\/span>Make the sample test a purchasing acceptance gate<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Agree the input condition, essential-load profile, dip waveform, repetition interval and pass\/fail voltage at the receiver. Test cold start with discharged storage, interruption after full charge, repeated interruptions and recovery with the normal load connected. Record the exact supply and storage revisions, actual capacitance condition, fixture and temperatures. A photograph of an assembled cabinet is not a ride-through result.<\/p>\n<p>If the sample fails, ask whether the limit is stored energy, charging current, voltage loss or receiver restart behavior before increasing capacitance. Retain the accepted configuration and change-notification requirements for repeat orders. Request quotations with sample and production quantities, destination and required documentation; delivery terms and availability must be confirmed for the order.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Buyer_questions\"><\/span>Buyer questions<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Can_the_specified_50_ms_simply_be_deducted_from_the_required_external_storage_time\"><\/span>Can the specified 50 ms simply be deducted from the required external storage time?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. That figure applies at 230 VAC and full load under the supplied sheet&#8217;s conditions. The receiver voltage, actual input, load profile and power-path losses can change the usable interval. Ask the supplier to confirm the conditions and verify the complete arrangement before allocating any part of the requirement to the supply&#8217;s internal storage.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Is_a_larger_output_capacitor_always_a_better_purchasing_choice\"><\/span>Is a larger output capacitor always a better purchasing choice?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. More capacitance can increase charging demand, recharge time and stored energy during service. Request an approved capacitance or charging arrangement and compare the complete sample against the agreed dip and restart tests, rather than buying the largest value that fits.<\/p>\n<p>Review <a href=\"https:\/\/www.wehopower.com\/fr\/product_category\/din-rail-power-supply\/\">WEHO DIN-rail power supplies<\/a> et <a href=\"https:\/\/www.wehopower.com\/fr\/contact\/\">send the essential-load and interruption specification to WEHO<\/a>. Ask explicitly for external-capacitance compatibility or an appropriate buffer architecture, rather than requesting \u201clonger hold-up\u201d without a voltage window.<\/p>\n<\/article>","protected":false},"excerpt":{"rendered":"<p>Turn a ride-through request into an energy budget, supplier interface review and repeatable OEM sample acceptance test.<\/p>","protected":false},"author":2,"featured_media":19228,"parent":0,"menu_order":43,"comment_status":"closed","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[149,284],"class_list":["post-19232","news","type-news","status-publish","format-standard","has-post-thumbnail","hentry","news_category-blog","news_category-product-articles","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/news\/19232","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/comments?post=19232"}],"version-history":[{"count":1,"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/news\/19232\/revisions"}],"predecessor-version":[{"id":19626,"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/news\/19232\/revisions\/19626"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/media\/19228"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/media?parent=19232"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/fr\/wp-json\/wp\/v2\/news_category?post=19232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}