{"id":2889,"date":"2026-07-30T15:00:00","date_gmt":"2026-07-30T15:00:00","guid":{"rendered":"https:\/\/chac-electric.com\/?p=2889"},"modified":"2026-07-21T09:22:50","modified_gmt":"2026-07-21T09:22:50","slug":"ev-high-voltage-dc-contactor-precharge-rfq","status":"publish","type":"post","link":"https:\/\/chac-electric.com\/es\/blog\/ev-high-voltage-dc-contactor-precharge-rfq\/","title":{"rendered":"Which Pre-Charge Inputs Should an OEM EV System RFQ Include?"},"content":{"rendered":"<div class=\"b2b-article\">\n<p style=\"margin:0 0 16px;line-height:1.7\"><strong>A pre-charge RFQ should identify the DC-link capacitance, voltage range, target sequence, peak-current limit, duty cycle and the exact contactor-control interface; a generic voltage or current label is not enough.<\/strong><\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/chac-electric.com\/wp-content\/uploads\/2026\/06\/cqc6-ac-contactor-wholesale-supplier.webp\" alt=\"ev contactor RFQ review for OEM teams\"><\/figure>\n<nav class=\"b2b-toc\" style=\"background:#f5f8fa;padding:16px 20px;border-radius:8px;margin:0 0 24px\">\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\">\u00cdndice<\/h2>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a href=\"#part-1-map-the-pre-charge-function-before-naming-a-contactor\">Part 1. Map the pre-charge function before naming a contactor<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-2-provide-the-electrical-inputs-that-define-the-event\">Part 2. Provide the electrical inputs that define the event<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-3-separate-pre-charge-duty-from-the-main-path-duty\">Part 3. Separate pre-charge duty from the main-path duty<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-4-define-the-control-and-diagnostic-interface\">Part 4. Define the control and diagnostic interface<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-5-record-environmental-and-assembly-constraints\">Part 5. Record environmental and assembly constraints<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-6-use-a-structured-rfq-and-evidence-request\">Part 6. Use a structured RFQ and evidence request<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-7-choose-the-chac-product-review-route\">Part 7. Choose the CHAC product-review route<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#faqs\">Preguntas frecuentes<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#references\">Referencias<\/a><\/li>\n<\/ul>\n<\/nav>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-1-map-the-pre-charge-function-before-naming-a-contactor\">Part 1. Map the pre-charge function before naming a contactor<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">The pre-charge branch limits inrush while a downstream DC-link capacitance charges before the main path closes. Texas Instruments describes a series current-limiting resistor and a pre-charge contactor arranged in parallel with the main positive contactor. State the intended sequence and the device role; do not treat this article as a protection-coordination approval.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-2-provide-the-electrical-inputs-that-define-the-event\">Part 2. Provide the electrical inputs that define the event<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Provide the system voltage range, downstream capacitance, acceptable pre-charge time, intended peak-current limit, expected repetition rate and the circuit diagram. Miba explains that peak current and stored-energy calculations depend on voltage, resistance and capacitance. The supplier must assess a selected model against the submitted conditions.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/chac-electric.com\/wp-content\/uploads\/2026\/06\/02-cqc6.webp\" alt=\"ev contactor technical review\"><\/figure>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-3-separate-pre-charge-duty-from-the-main-path-duty\">Part 3. Separate pre-charge duty from the main-path duty<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">A pre-charge contactor and a main-path contactor can see different switching events. Identify whether the requested component is in the resistor branch or the main path, then include the normal operating sequence and abnormal-state requirements. Do not infer interruption performance from another position in the circuit.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-4-define-the-control-and-diagnostic-interface\">Part 4. Define the control and diagnostic interface<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Include the available coil-drive supply, command logic, feedback requirement, controller interlocks and fault-handling expectations. TI notes that coil drive must be considered across a changing battery voltage. Ask for the supplier documentation that applies to the proposed control arrangement.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-5-record-environmental-and-assembly-constraints\">Part 5. Record environmental and assembly constraints<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Describe enclosure conditions, mounting space, harness and terminal constraints, vibration exposure where relevant, service access and the required project documentation. These conditions belong in the RFQ because they cannot be recovered from a generic product-family description.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-6-use-a-structured-rfq-and-evidence-request\">Part 6. Use a structured RFQ and evidence request<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Attach the single-line diagram, timing expectation, electrical inputs, environmental conditions, requested documents and the target market requirements. Request model-specific evidence for every required rating, standard or certification instead of accepting a family-level assumption.<\/p>\n<h3 style=\"margin:28px 0 12px\">Recomendaci\u00f3n de producto<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\"><a href=\"https:\/\/chac-electric.com\/es\/high-voltage-dc-contactor\/\">CHAC Electric high voltage dc contactor category<\/a> is the relevant product-family starting point after the RFQ is complete. <a href=\"https:\/\/chac-electric.com\/es\/industrial-control-customization\/\">Send the confirmed requirements through the customization route<\/a> or <a href=\"https:\/\/chac-electric.com\/es\/contact-us\/\">Contactar a CHAC Electric<\/a> for the next review.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/chac-electric.com\/wp-content\/uploads\/2026\/06\/03-cqc6.webp\" alt=\"CHAC Electric high voltage dc contactor product review\"><\/figure>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-7-choose-the-chac-product-review-route\">Part 7. Choose the CHAC product-review route<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Use CHAC Electric&#8217;s published high-voltage DC contactor category as the starting point for a product-family discussion after the RFQ is complete. It is not a statement that any listed item fits the submitted system.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"faqs\">Preguntas frecuentes<\/h2>\n<h3 style=\"margin:28px 0 12px\">What does a pre-charge contactor do in an EV DC link?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">It helps charge downstream capacitance through a current-limiting branch before the main path closes, subject to the documented circuit sequence.<\/p>\n<h3 style=\"margin:28px 0 12px\">Which electrical values belong in the RFQ?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">State the voltage range, capacitance, target time, peak-current limit, duty cycle and the circuit diagram.<\/p>\n<h3 style=\"margin:28px 0 12px\">Why is capacitance important?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Stored energy and the charging event depend on capacitance and voltage, so it affects the resistor and switching review.<\/p>\n<h3 style=\"margin:28px 0 12px\">Can a category page confirm model suitability?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">No. It is a product-family entry point; final suitability requires project inputs and selected-model documentation.<\/p>\n<h3 style=\"margin:28px 0 12px\">Should the control interface be specified?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Yes. Include the available drive supply, command logic, feedback and interlock expectations.<\/p>\n<h3 style=\"margin:28px 0 12px\">What is outside this article&#8217;s scope?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">It does not replace model-specific validation, functional-safety review, fault protection design or live-work instructions.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"references\">Referencias<\/h2>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/www.ti.com\/lit\/wp\/slvaf35a\/slvaf35a.pdf\" rel=\"nofollow noopener\" target=\"_blank\">Texas Instruments pre-charge contactor guide<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/www.ti.com\/lit\/an\/sdaa145a\/sdaa145a.pdf\" rel=\"nofollow noopener\" target=\"_blank\">Texas Instruments DC-link pre-charge designs<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/www.miba.com\/en\/product-areas\/power-electronics\/precharge-resistor-calculation\" rel=\"nofollow noopener\" target=\"_blank\">Miba pre-charge resistor calculation guide<\/a><\/li>\n<\/ul>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>A pre-charge RFQ should identify the DC-link capacitance, voltage range, target sequence, peak-current limit, duty cycle and the exact contactor-control interface; a generic voltage or current label is not enough. Contents Part 1. Map the pre-charge function before naming a contactor Part 2. Provide the electrical inputs that define the event Part 3. Separate pre-charge [&hellip;]<\/p>\n","protected":false},"author":10,"featured_media":1212,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2889","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/posts\/2889","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/comments?post=2889"}],"version-history":[{"count":1,"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/posts\/2889\/revisions"}],"predecessor-version":[{"id":2909,"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/posts\/2889\/revisions\/2909"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/media\/1212"}],"wp:attachment":[{"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/media?parent=2889"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/categories?post=2889"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/chac-electric.com\/es\/wp-json\/wp\/v2\/tags?post=2889"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}