{"id":2223,"date":"2026-07-29T15:00:00","date_gmt":"2026-07-29T07:00:00","guid":{"rendered":"https:\/\/cnbygele.com\/?p=2223"},"modified":"2026-07-29T00:12:29","modified_gmt":"2026-07-28T16:12:29","slug":"harmonic-resonance-troubleshooting-capacitor-switching","status":"publish","type":"post","link":"https:\/\/cnbygele.com\/fr\/blog\/harmonic-resonance-troubleshooting-capacitor-switching\/","title":{"rendered":"D\u00e9pannage de r\u00e9sonance harmonique apr\u00e8s commutation de condensateur"},"content":{"rendered":"<div class=\"b2b-article\">\n<p style=\"margin:0 0 16px;line-height:1.7\"><strong>Diagnosing a thd increase observed after capacitor bank stages switch should begin with a documented electrical boundary, representative operating record, and a defined decision.<\/strong> A meter reading, a component nameplate, or a single switching event does not by itself establish the cause, the required equipment, or the acceptance criteria.<\/p>\n<nav class=\"b2b-toc\" style=\"background:#f5f8fa;padding:16px 20px;border-radius:8px;margin:0 0 24px\">\n<h2 id=\"contents\" style=\"margin:42px 0 14px;scroll-margin-top:96px\">Contenu<\/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-define-the-decision-boundary\">Part 1. Define the decision boundary<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-2-capture-representative-operating-states\">Part 2. Capture representative operating states<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-3-keep-standards-and-installation-responsibilities-explicit\">Part 3. Keep standards and installation responsibilities explicit<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-4-compare-paths-without-defaulting-to-one-device\">Part 4. Compare paths without defaulting to one device<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-5-plan-interfaces-and-commissioning-early\">Part 5. Plan interfaces and commissioning early<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-6-rfq-checklist-and-fit-boundary\">Part 6. RFQ checklist and fit boundary<\/a><\/li>\n<\/ul>\n<\/nav>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"direct-answer\">R\u00e9ponse directe<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Diagnosing a thd increase observed after capacitor bank stages switch should begin with a documented electrical boundary, representative operating record, and a defined decision. A meter reading, a component nameplate, or a single switching event does not by itself establish the cause, the required equipment, or the acceptance criteria.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">CNBYG can discuss Three-Phase Series Filter Reactor product-line context when the recorded evidence supports a defined objective. It cannot establish a remote diagnosis of a specific site, a default tuning prescription, or a promised corrective outcome from an article. For broader navigation, see <a href=\"https:\/\/cnbygele.com\/fr\/power-quality-system-guides\/\">Guides sur la qualit\u00e9 de l'alimentation \u00e9lectrique<\/a>.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-1-define-the-decision-boundary\">Part 1. Define the decision boundary<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Start by naming the point where the result will be used. A feeder measurement characterizes a local source; a service entrance, transformer secondary, or PCC measurement supports a system-boundary question. Record meter location, voltage reference, CT ratio and polarity, sample interval, aggregation period, and other major loads connected at the time.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">For industrial capacitor banks interacting with nonlinear load and system impedance, the operating log should identify each capacitor-stage state, changing nonlinear-load levels, transformer configuration, and the event immediately before and after switching. Time stamps matter because a change in load, source configuration, or capacitor state can alter the observed waveform without proving an equipment fault.<\/p>\n<table style=\"width:100%;border-collapse:collapse\">\n<thead>\n<tr>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Question de mesure<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Evidence to retain<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">D\u00e9cision soutenue<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">What occurs at the capacitor-bank bus and the upstream system boundary?<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Current\/voltage trends, spectra, CT position, operating state<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Source characterization<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">What changes at the system boundary?<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Demand, source and transformer data, switching record<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Project target definition<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">La condition est-elle reproductible ?<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Multiple representative operating windows<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Planification de la capacit\u00e9 et de la mise en service<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">What is already installed?<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">D\u00e9tails de ligne unique, condensateur\/r\u00e9acteur\/filtre et protection<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Integration review<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-2-capture-representative-operating-states\">Part 2. Capture representative operating states<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">An effective record uses more than a snapshot. Log normal and abnormal windows, note the sequence of switching or control events, and preserve the settings used by the analyzer. Where individual feeders are available, correlate them with the bus result rather than assuming that one load explains every change.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Keep a baseline before any physical change. The baseline should include RMS voltage and current, harmonic spectrum, demand, reactive-power trend, equipment state, and the operating schedule. If a later comparison uses another meter position or another production condition, label that limitation rather than treating unlike data as proof of improvement.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-3-keep-standards-and-installation-responsibilities-explicit\">Part 3. Keep standards and installation responsibilities explicit<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">La <a href=\"https:\/\/standards.ieee.org\/ieee\/519\/5892\/\" rel=\"nofollow noopener\" target=\"_blank\">Aper\u00e7u de la norme IEEE 519<\/a> provides context for harmonic-control discussions, but it is not a universal sizing instruction. The applicable assessment point, source characteristics, operating data, and contractual criteria must be established for the project.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">For U.S. work, <a href=\"https:\/\/www.nfpa.org\/codes-and-standards\/nfpa-70-standard-development\/70\" rel=\"nofollow noopener\" target=\"_blank\">NFPA 70 \/ NEC<\/a> is relevant code context, subject to the adopted edition, local amendments, equipment instructions, and AHJ review. Disconnects, overcurrent protection, conductors, grounding and bonding, labeling, working space, and access should be resolved by the responsible design and installation team.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-4-compare-paths-without-defaulting-to-one-device\">Part 4. Compare paths without defaulting to one device<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">The selected path should follow the measured objective. Harmonic current, reactive demand, voltage events, installation defects, and upstream conditions can occur together, yet they need different evidence and acceptance methods. Existing compensation, reactors, filters, source impedance, protection, and expected load variation all influence a project review.<\/p>\n<table style=\"width:100%;border-collapse:collapse\">\n<thead>\n<tr>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Cat\u00e9gorie d'option<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Peut \u00eatre envisag\u00e9 lorsque<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Doit \u00eatre confirm\u00e9<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">AHF \/ APF<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Measured harmonic-current mitigation is the objective<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Current profile, CT plan, location, capacity, protection, heat<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">SVG<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Dynamic reactive-power behavior is the objective<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Reactive profile, voltage context, controls, existing equipment<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Series reactor \/ passive components<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">A system study defines a fixed or tuned function<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Resonance, switching, network data, physical installation<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Changement op\u00e9rationnel ou en amont<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Source, schedule, or topology is material<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Owner duties, utility coordination, implementation path<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"margin:0 0 16px;line-height:1.7\">Pour une discussion sur la ligne de produits, voir <a href=\"https:\/\/cnbygele.com\/fr\/produit\/three-phase-series-filter-reactor\/\">CNBYG R\u00e9acteur de filtre s\u00e9rie triphas\u00e9<\/a>. This is a product recommendation boundary, not a conclusion that the product is suitable for every observed condition. The related guide on <a href=\"https:\/\/cnbygele.com\/fr\/blog\/preventing-capacitor-harmonic-resonance-in-industrial-systems\/\">Pr\u00e9venir la r\u00e9sonance harmonique des condensateurs<\/a> provides a neighboring measurement-led perspective.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-5-plan-interfaces-and-commissioning-early\">Part 5. Plan interfaces and commissioning early<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Before an RFQ, document the proposed connection location, CT arrangement, feeder and bus topology, available fault-current information, cable routes, ventilation, environmental conditions, access, communications, alarms, and maintenance expectations. Those inputs keep a quotation discussion tied to the actual integration scope.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Commissioning should compare like operating states against a pre-agreed baseline and acceptance method. Retain the meter position, analyzer setup, and major load state for both records. A changed meter location or changed operating condition can produce a different result without proving a change in equipment performance. See <a href=\"https:\/\/cnbygele.com\/fr\/blog\/anti-harmonic-intelligent-capacitors-vs-active-filtering\/\">Intelligent capacitors versus active filtering<\/a> for related planning context.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"part-6-rfq-checklist-and-fit-boundary\">Part 6. RFQ checklist and fit boundary<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">An inquiry is more useful with a single-line diagram, nominal voltage and frequency, transformer data, representative voltage\/current records, load schedule, existing capacitor\/reactor\/filter inventory, protection data, proposed installation point, space and cooling details, and communication requirements. State whether the decision concerns local troubleshooting, a system boundary, harmonic current, reactive response, or an integration review.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">CNBYG can review these inputs and discuss product-line fit. It should not be asked to promise a remote diagnosis of a specific site, a default tuning prescription, or a promised corrective outcome. For regulated, critical, or unusual conditions, involve the owner, qualified engineer, installer, utility where relevant, and AHJ. Submit the available project information through the <a href=\"https:\/\/cnbygele.com\/fr\/contact-us\/\">Page de contact CNBYG<\/a>.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"frequently-asked-questions\">Foire aux questions<\/h2>\n<h3 style=\"margin:28px 0 12px\">Why can THD increase after a capacitor stage closes?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">A capacitor changes network impedance. With nonlinear current present, the changed impedance can amplify a frequency range; measurements and network data are needed to test that explanation.<\/p>\n<h3 style=\"margin:28px 0 12px\">Should the capacitor bank be changed immediately after a THD event?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Do not treat a single event as a sizing instruction. Preserve the event record, establish safe operating controls, and have qualified personnel evaluate the network and switching evidence.<\/p>\n<h3 style=\"margin:28px 0 12px\">Can a reactor setting be selected from the THD reading alone?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">No. Selection requires the system voltage, capacitor details, transformer and source information, measured spectrum, switching behavior, protection, and a project-specific study.<\/p>\n<h3 style=\"margin:28px 0 12px\">Une seule mesure est-elle suffisante pour s\u00e9lectionner le mat\u00e9riel d'att\u00e9nuation ?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Usually not. Meter location, operating condition, duration, electrical topology, and the project objective determine whether the data is representative.<\/p>\n<h3 style=\"margin:28px 0 12px\">Peut-on s\u00e9lectionner un \u00e9quipement uniquement \u00e0 partir de la charge connect\u00e9e ?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">No. A capacity discussion needs measured behavior, an operating profile, installation topology, and a defined acceptance objective.<\/p>\n<h3 style=\"margin:28px 0 12px\">Cet article garantit-il un r\u00e9sultat de conformit\u00e9 ou op\u00e9rationnel ?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">No. Site conditions, standards application, acceptance criteria, and commissioning must be confirmed for the specific project.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"references\">R\u00e9f\u00e9rences<\/h2>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/standards.ieee.org\/ieee\/519\/5892\/\" rel=\"nofollow noopener\" target=\"_blank\">IEEE 519 \u2014 Contr\u00f4le harmonique dans les syst\u00e8mes d'\u00e9nergie \u00e9lectrique<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/www.nfpa.org\/codes-and-standards\/nfpa-70-standard-development\/70\" rel=\"nofollow noopener\" target=\"_blank\">NFPA 70 \u2014 National Electrical Code information<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/www.nema.org\/standards\/view\/motors-and-generators\" rel=\"nofollow noopener\" target=\"_blank\">NEMA MG 1 \u2014 Moteurs et G\u00e9n\u00e9rateurs<\/a><\/li>\n<\/ul>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Diagnosing a thd increase observed after capacitor bank stages switch should begin with a documented electrical boundary, representative operating record, and a defined decision. A meter reading, a component nameplate, or a single switching event does not by itself establish the cause, the required equipment, or the acceptance criteria. Contents Part 1. Define the decision [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":1913,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_gspb_post_css":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-2223","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"blocksy_meta":[],"acf":[],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/posts\/2223","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/comments?post=2223"}],"version-history":[{"count":3,"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/posts\/2223\/revisions"}],"predecessor-version":[{"id":2297,"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/posts\/2223\/revisions\/2297"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/media\/1913"}],"wp:attachment":[{"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/media?parent=2223"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/categories?post=2223"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnbygele.com\/fr\/wp-json\/wp\/v2\/tags?post=2223"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}