{"id":20532,"date":"2026-11-01T10:40:43","date_gmt":"2026-11-01T02:40:43","guid":{"rendered":"https:\/\/www.wehopower.com\/news\/dr15-dc-relay-breaking-rating\/"},"modified":"2026-11-01T10:45:28","modified_gmt":"2026-11-01T02:45:28","slug":"dr15-dc-relay-breaking-rating","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/fa\/news\/dr15-dc-relay-breaking-rating\/","title":{"rendered":"Switching a DC Load: Check the Relay Breaking Rating Before the Supply Current"},"content":{"rendered":"<div class=\"weho-blog-content\">\n<p><strong>Select a relay from its documented DC switching capability for the actual load, then verify the complete assembly under the required duty.<\/strong> The supply\u2019s available output current does not establish what the relay contacts can reliably interrupt.<\/p>\n<p>For a panel buyer using a WEHO DR-15 supply, the deliverable is a relay qualification record covering contact voltage, load type, switching conditions and required life. Keep this contact decision separate from the relay coil\u2019s own supply requirements.<\/p>\n<nav class=\"toc\" aria-label=\"Article contents\">\n<p>In this article<\/p>\n<ol>\n<li><a href=\"#different-ratings\">Separate supply output, relay coil and relay contacts<\/a><\/li>\n<li><a href=\"#load-evidence\">Describe the load that the contacts must interrupt<\/a><\/li>\n<li><a href=\"#curve\">Read the manufacturer curve as a combined condition<\/a><\/li>\n<li><a href=\"#suppression\">Treat suppression as part of the qualified configuration<\/a><\/li>\n<li><a href=\"#example\">A hypothetical valve review shows why spare watts are insufficient<\/a><\/li>\n<li><a href=\"#release\">Release the exact relay-and-load combination<\/a><\/li>\n<\/ol>\n<\/nav>\n<section id=\"different-ratings\">\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\">\u0641\u0647\u0631\u0633\u062a \u0645\u0637\u0627\u0644\u0628<\/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=\"\u062a\u063a\u06cc\u06cc\u0631 \u0648\u0636\u0639\u06cc\u062a \u0641\u0647\u0631\u0633\u062a \u0645\u0637\u0627\u0644\u0628\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">\u062a\u063a\u06cc\u06cc\u0631 \u0648\u0636\u0639\u06cc\u062a \u062f\u0647\u06cc\u062f<\/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\/fa\/news\/dr15-dc-relay-breaking-rating\/#Separate_supply_output_relay_coil_and_relay_contacts\" >Separate supply output, relay coil and relay contacts<\/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\/fa\/news\/dr15-dc-relay-breaking-rating\/#Describe_the_load_that_the_contacts_must_interrupt\" >Describe the load that the contacts must interrupt<\/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\/fa\/news\/dr15-dc-relay-breaking-rating\/#Read_the_manufacturer_curve_as_a_combined_condition\" >Read the manufacturer curve as a combined condition<\/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\/fa\/news\/dr15-dc-relay-breaking-rating\/#Treat_suppression_as_part_of_the_qualified_configuration\" >Treat suppression as part of the qualified configuration<\/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\/fa\/news\/dr15-dc-relay-breaking-rating\/#A_hypothetical_valve_review_shows_why_spare_watts_are_insufficient\" >A hypothetical valve review shows why spare watts are insufficient<\/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\/fa\/news\/dr15-dc-relay-breaking-rating\/#Release_the_exact_relay-and-load_combination\" >Release the exact relay-and-load combination<\/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\/fa\/news\/dr15-dc-relay-breaking-rating\/#Use_the_project_record\" >Use the project record<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.wehopower.com\/fa\/news\/dr15-dc-relay-breaking-rating\/#Review_the_DR-15_source_requirements_alongside_the_load_record\" >Review the DR-15 source requirements alongside the load record<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.wehopower.com\/fa\/news\/dr15-dc-relay-breaking-rating\/#Sources_and_further_reading\" >Sources and further reading<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Separate_supply_output_relay_coil_and_relay_contacts\"><\/span>Separate supply output, relay coil and relay contacts<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0631\u0627 <a href=\"https:\/\/www.wehopower.com\/fa\/product\/high-quality-dr-15-15w-smps-switching-power-supply\/\">WEHO DR-15 product information<\/a> and <a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2023\/02\/High-Quality-DR-15-15w-Smps-Switching-Power-Supply.pdf\">DR-15 specification sheet<\/a> include a 24 V output option. That makes the family a relevant small DC-source example. It does not certify a relay, solenoid or complete load assembly.<\/p>\n<p>There are three different questions: can the supply support the required load; can the control circuit operate the relay coil correctly; and can the contacts make, carry and break the load circuit under its actual conditions? A 24 V coil marking answers only part of the second question. It is not a 24 V DC contact-load approval.<\/p>\n<p>Likewise, a prominently printed contact-current value may refer to a particular voltage and load category. Ask for the exact data table and switching-capacity curve instead of treating the number on the relay case as a complete specification.<\/p>\n<figure class=\"figure\" id=\"figure-diagram\"><picture><source media=\"(max-width: 600px)\" srcset=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/decision-map-mobile-1.svg\" width=\"480\" height=\"1390\" type=\"image\/svg+xml\"><img loading=\"lazy\" src=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/decision-map-1.svg\" alt=\"Switching a DC Load: Check the Relay Breaking Rating Before the Supply Current  title=\" width=\"1200\" height=\"740\" decoding=\"async\" switching dc load: check the relay breaking rating before supply current title =\"\"><\/picture><figcaption>The supply rating is not the relay breaking rating. Four independent checks qualify a DC switching combination: contact voltage\/current, load characteristics, required endurance, and suppression with release behavior. <a class=\"original-link\" href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2026\/11\/decision-map-1.svg\">View original image<\/a><\/figcaption><\/figure>\n<\/section>\n<section id=\"load-evidence\">\n<h2><span class=\"ez-toc-section\" id=\"Describe_the_load_that_the_contacts_must_interrupt\"><\/span>Describe the load that the contacts must interrupt<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/www.ia.omron.com\/support\/faq\/answer\/36\/faq02771\/\" target=\"_blank\" rel=\"noopener\">OMRON\u2019s relay guidance<\/a> explains that inductive-load switching capacity is generally lower than resistive-load capacity because of stored electromagnetic energy. Its published examples distinguish AC and DC load conditions. Those example ratings belong to the named OMRON products, not to an arbitrary relay connected to a DR-15.<\/p>\n<p>Give the relay supplier the actual DC voltage range and current conditions at opening and closing. Identify whether the switched load is resistive, a coil, another inductive device or equipment with its own electronics. For an inductive load, obtain the load data needed to compare the relay\u2019s stated time-constant or other specified conditions.<\/p>\n<div class=\"table-wrap\">\n<table>\n<thead>\n<tr>\n<th scope=\"col\">Record field<\/th>\n<th scope=\"col\">Evidence to obtain<\/th>\n<th scope=\"col\">Decision it supports<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<th scope=\"row\">Exact contact arrangement<\/th>\n<td>Relay suffix, contact form, contact material where specified and manufacturer connection restrictions.<\/td>\n<td>Ensures the curve applies to the offered device.<\/td>\n<\/tr>\n<tr>\n<th scope=\"row\">DC voltage and current<\/th>\n<td>Applicable contact-load range and opening\/closing conditions.<\/td>\n<td>Places the real duty on the correct manufacturer curve.<\/td>\n<\/tr>\n<tr>\n<th scope=\"row\">Load characteristics<\/th>\n<td>Resistive or inductive classification and required load data.<\/td>\n<td>Avoids substituting a resistive rating for an inductive task.<\/td>\n<\/tr>\n<tr>\n<th scope=\"row\">Switching duty and life<\/th>\n<td>Operating frequency, required cycles and endurance conditions.<\/td>\n<td>Separates a maximum switching boundary from the required service life.<\/td>\n<\/tr>\n<tr>\n<th scope=\"row\">Suppression and release<\/th>\n<td>Exact approved protection arrangement and required release behavior.<\/td>\n<td>Checks both contact protection and the equipment\u2019s response.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>If the load description is missing, record \u201cselection evidence incomplete.\u201d Do not reclassify an unknown load as resistive because its normal current is small.<\/p>\n<\/section>\n<section id=\"curve\">\n<h2><span class=\"ez-toc-section\" id=\"Read_the_manufacturer_curve_as_a_combined_condition\"><\/span>Read the manufacturer curve as a combined condition<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/www.ia.omron.com\/support\/faq\/answer\/36\/faq02763\/\" target=\"_blank\" rel=\"noopener\">OMRON\u2019s maximum-switching-capacity explanation<\/a> evaluates contact voltage together with current on the appropriate AC\/DC and load curve. This is why separate maximum-voltage and maximum-current fields cannot simply be combined into one assumed operating point.<\/p>\n<p>For procurement, ask the relay supplier to identify the applicable curve and the proposed duty on it. Retain the curve revision and its conditions in the project file. If the published curve does not cover the load or endurance requirement, seek written application guidance or another relay rather than extrapolating an approval.<\/p>\n<p>Check the meanings of any carry-current, maximum-switching-current and endurance entries separately. A contact that can conduct a stated current when closed is not thereby shown to break every load at that current. The acceptable operating point and expected life must come from the applicable documentation and validation.<\/p>\n<\/section>\n<section id=\"suppression\">\n<h2><span class=\"ez-toc-section\" id=\"Treat_suppression_as_part_of_the_qualified_configuration\"><\/span>Treat suppression as part of the qualified configuration<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"https:\/\/www.ia.omron.com\/support\/faq\/answer\/36\/faq02804\/index.html\" target=\"_blank\" rel=\"noopener\">OMRON\u2019s contact-protection guidance<\/a> describes different suppression approaches and notes that protection can alter release time. For a DC inductive load, that means contact-protection performance and load-release behavior need to be considered together.<\/p>\n<p>Do not add an unspecified diode or other suppressor and assume the whole decision is resolved. Use the design approved for the exact load and switching device. Record the component identity, manufacturer instructions and the required timing behavior in the assembly\u2019s qualification package.<\/p>\n<p>The relay coil and the switched load can also be separate inductive elements. Identify which one a protection claim concerns. A feature built into the relay\u2019s coil circuit does not automatically protect the separate load switched by its contacts.<\/p>\n<\/section>\n<section id=\"example\">\n<h2><span class=\"ez-toc-section\" id=\"A_hypothetical_valve_review_shows_why_spare_watts_are_insufficient\"><\/span>A hypothetical valve review shows why spare watts are insufficient<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Consider a small panel whose DR-15 output option has already been checked against its steady load. A supplier proposes a relay because its headline contact-current rating is larger than that load. The controlled device is a DC solenoid, but the quotation includes only an AC resistive rating.<\/p>\n<p>The review remains open. Request the proposed relay\u2019s DC inductive switching data, applicable load conditions, required life and approved suppression configuration. More unused supply capacity would not supply that missing evidence. A larger source may change available fault energy, but it does not grant a relay a new breaking rating.<\/p>\n<p>This example describes a document decision, not a tested DR-15\/valve combination. Once a candidate is supported by the data, the responsible engineering team should verify actual load operation, release behavior and the required endurance basis using an approved test plan.<\/p>\n<\/section>\n<section id=\"release\">\n<h2><span class=\"ez-toc-section\" id=\"Release_the_exact_relay-and-load_combination\"><\/span>Release the exact relay-and-load combination<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Close the record with the selected relay suffix, contact-load evidence, suppression version, required duty and validation disposition. Preserve open items that affect interruption or release behavior; do not hide them under a general \u201cpower supply checked\u201d approval.<\/p>\n<p>Keep substitutions under the same review. A replacement relay with the same coil voltage, footprint and headline current may have different DC load curves or endurance conditions. Purchasing can prevent an unsupported substitution by including those conditions in the approved-part record.<\/p>\n<\/section>\n<section id=\"project-record\">\n<h2><span class=\"ez-toc-section\" id=\"Use_the_project_record\"><\/span>Use the project record<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><a href=\"\/fa\/acceptance-record.html\/\">Open the blank DC Load Relay \u2014 Switching Qualification Record<\/a> to record your conditions, evidence and decisions. The worksheet contains no pre-approved result.<\/p>\n<\/section>\n<section class=\"cta\" id=\"project-review\">\n<h2><span class=\"ez-toc-section\" id=\"Review_the_DR-15_source_requirements_alongside_the_load_record\"><\/span>Review the DR-15 source requirements alongside the load record<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Send WEHO the requested DR-15 output version, complete load list, operating duty and any startup or transient conditions. Use the relay manufacturer\u2019s exact contact data to qualify switching; request WEHO\u2019s applicable supply documents for the source side of that review.<\/p>\n<p><a href=\"https:\/\/www.wehopower.com\/fa\/contact\/\">Contact WEHO about DR-15 supply documentation<\/a><\/p>\n<\/section>\n<section class=\"sources\" id=\"sources\">\n<h2><span class=\"ez-toc-section\" id=\"Sources_and_further_reading\"><\/span>Sources and further reading<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<ol>\n<li><a href=\"https:\/\/www.wehopower.com\/fa\/product\/high-quality-dr-15-15w-smps-switching-power-supply\/\">WEHO DR-15 DIN-rail supply product information<\/a><\/li>\n<li><a href=\"https:\/\/www.wehopower.com\/wp-content\/uploads\/2023\/02\/High-Quality-DR-15-15w-Smps-Switching-Power-Supply.pdf\">WEHO DR-15 specification sheet<\/a><\/li>\n<li><a href=\"https:\/\/www.ia.omron.com\/support\/faq\/answer\/36\/faq02771\/\" target=\"_blank\" rel=\"noopener\">OMRON FAQ02771 \u2014 Load type and relay switching capacity<\/a><\/li>\n<li><a href=\"https:\/\/www.ia.omron.com\/support\/faq\/answer\/36\/faq02763\/\" target=\"_blank\" rel=\"noopener\">OMRON FAQ02763 \u2014 Maximum switching-capacity curves<\/a><\/li>\n<li><a href=\"https:\/\/www.ia.omron.com\/support\/faq\/answer\/36\/faq02804\/index.html\" target=\"_blank\" rel=\"noopener\">OMRON FAQ02804 \u2014 Contact protection and release behavior<\/a><\/li>\n<\/ol>\n<\/section>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>A small supply does not automatically make any relay suitable. Check what the contacts must interrupt at the actual DC voltage, load and duty.<\/p>","protected":false},"author":2,"featured_media":20543,"parent":0,"menu_order":51,"comment_status":"closed","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[284],"class_list":["post-20532","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\/fa\/wp-json\/wp\/v2\/news\/20532","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/comments?post=20532"}],"version-history":[{"count":1,"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/news\/20532\/revisions"}],"predecessor-version":[{"id":20542,"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/news\/20532\/revisions\/20542"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/media\/20543"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/media?parent=20532"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/fa\/wp-json\/wp\/v2\/news_category?post=20532"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}