{"id":1806,"date":"2026-11-06T00:18:31","date_gmt":"2026-11-06T00:18:31","guid":{"rendered":"https:\/\/subiapower.com\/?p=1806"},"modified":"2026-11-14T07:46:48","modified_gmt":"2026-11-14T07:46:48","slug":"what-is-a-ring-main-unit-rmu-how-it-works-in-secondary-distribution","status":"publish","type":"post","link":"https:\/\/subiapower.com\/es\/what-is-a-ring-main-unit-rmu-how-it-works-in-secondary-distribution\/","title":{"rendered":"\u00bfQu\u00e9 es una unidad de red en anillo (RMU)? C\u00f3mo funciona en la distribuci\u00f3n secundaria"},"content":{"rendered":"<style>.subia-article-article{max-width:900px;margin:0 auto;line-height:1.7}.subia-article-article h2{margin-top:2.2em}.subia-article-article h3{margin-top:1.7em}.subia-article-article figure{margin:2em 0}.subia-article-article img{display:block;max-width:100%;height:auto;margin:auto}.subia-article-article figcaption{font-size:.9em;line-height:1.5;color:#555;margin-top:.7em}.subia-article-article .subia-table-scroll{max-width:100%;overflow-x:auto;margin:1.5em 0}.subia-article-article table{display:table;width:100%;border-collapse:collapse;margin:0}.subia-article-article th,.subia-article-article td{padding:.7em;border:1px solid #ddd;vertical-align:top;min-width:130px;overflow-wrap:normal;word-break:normal;hyphens:none}.subia-article-article th{background:#f4f4f4}.subia-article-article a{text-decoration:underline;overflow-wrap:anywhere}@media(max-width:600px){.subia-article-article{font-size:16px}.subia-article-article .subia-table-scroll table{min-width:660px}.subia-article-article .subia-table-scroll[data-columns=\"2\"] table{min-width:600px;table-layout:fixed}.subia-article-article .subia-table-scroll::before{content:\"Swipe to read all columns\";display:block;position:sticky;left:0;font-size:13px;color:#555;margin-bottom:8px}.subia-article-article th,.subia-article-article td{padding:.65em;min-width:180px}}<\/style>\n<div class=\"subia-article-article\" data-subia-article=\"SUBIA-P25\" lang=\"en\">\n<h2>Quick Takeaway<\/h2>\n<ul>\n<li>A common RMU arrangement has two ring ways for MV cables and a separate protected way for a transformer.<\/li>\n<li>A normally open point separates the feeding sections of a cable loop during normal operation.<\/li>\n<li>After a cable fault is isolated, a suitable alternate path may restore supply to healthy sections if capacity and protection permit it.<\/li>\n<\/ul>\n<p>A ring main unit (RMU) is a compact medium-voltage switchgear assembly used in secondary distribution. In the ring-fed example followed here, it connects a substation into a looped MV cable network and provides a branch to a separate transformer. RMU configurations can also serve other feeder arrangements. It does not change voltage. The separately connected transformer at the substation does that work. The RMU&#8217;s job is to switch MV circuits, allow the cable ring to pass through the substation, and provide a protected connection point for the transformer branch.<\/p>\n<p>Understanding an RMU starts with its physical structure and what each internal way does, before moving to how those ways behave in a network, and what happens when a cable section fails.<\/p>\n<h2>What the Two Ring Ways and Transformer Way Do<\/h2>\n<p>A common ring-fed secondary substation uses a compact assembly built around two ring load-break ways and a separate transformer protection way. The illustration labels the ring ways Ring way A and Ring way B; actual panel identifiers follow the equipment and network drawings. The transformer connection is a distinct third branch.<\/p>\n<p>Ring way A and Ring way B provide the two cable directions through the unit. Which one is supplying the bus depends on the network state, so the labels are not permanent input and output assignments. Each connects to an MV cable running to the next point in the network \u2014 an adjacent substation or a feeder origin. Together, they form the through-route that makes this substation a node in the ring. When both ring ways are closed, MV current can enter from one cable direction, travel through the internal bus, and exit toward the next point. This is the structural feature that distinguishes a ring substation from a simple radial tap: the cable ring has a physical continuation through the switchgear.<\/p>\n<p>The transformer way is a separate branch off that internal bus. In this configuration it serves a separately installed transformer rather than continuing the ring cable route. Its switching and protective arrangement is selected for that transformer circuit. A plain load-break switch performs its specified load-switching duty; fault interruption requires a device rated for that duty. A coordinated switch-fuse combination is one common arrangement; a circuit breaker with a relay is another. The choice depends on the protection coordination requirements of the specific network. The RMU provides the switching and protection function at the MV side; the transformer then steps the voltage down to the low-voltage level for the LV distribution board inside the substation.<\/p>\n<figure class=\"wp-block-image size-full\" data-media-role=\"inline\"><img class=\"wp-image-1802\" src=\"https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig01-final-11.webp\" alt=\"Two ring ways form a path through the RMU and a third way branches to a separate transformer.\" width=\"1536\" height=\"1024\" loading=\"lazy\" decoding=\"async\" srcset=\"https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig01-final-11.webp 1536w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig01-final-11-300x200.webp 300w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig01-final-11-1024x683.webp 1024w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig01-final-11-768x512.webp 768w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig01-final-11-18x12.webp 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><figcaption>In this three-way example, the transformer feeder branches from the route through the RMU.<\/figcaption><\/figure>\n<p>This three-way layout \u2014 two ring load-break ways plus one protected transformer way \u2014 is a recognizable and widely used configuration in secondary distribution. It is one example, not a universal rule: RMUs exist with different numbers of ways, different insulation technologies, and different combinations of protection equipment, depending on the network requirements. In the illustrated configuration, keep the functional distinction clear: the ring path carries MV current through the unit, and the transformer branch taps off to supply the local transformer. A different way arrangement must be read from its own single-line diagram.<\/p>\n<p><a href=\"https:\/\/www.electrical-installation.org\/enwiki\/Choice_of_MV_equipment\" target=\"_blank\" rel=\"noopener\">Schneider Electric\u2019s MV equipment guide<\/a> shows a typical ring-fed arrangement.<\/p>\n<p>One point worth making explicit: the RMU is switchgear, not a transformer. Its main power circuits operate at MV; control and indication circuits may use auxiliary voltages. The transformer is a separate piece of equipment connected to the transformer way. Confusing the two leads to misreading the single-line diagram and misstating the equipment scope during procurement.<\/p>\n<h2>How a Normally Open Ring Feeds Substations<\/h2>\n<p>A cable network can be physically looped while operated with a normally open point. In the arrangement used here, that deliberate opening divides the route into two feeding sections during normal operation. A closed-ring operating scheme is a different network design; the physical loop alone does not determine the normal operating state.<\/p>\n<p>A simple illustrative arrangement clarifies this. Consider three RMU substations in sequence along a cable route: Feeder A \u2014 RMU 1 \u2014 RMU 2 \u2014 [normally open point] \u2014 RMU 3 \u2014 Feeder B. This traces the full ring route from one feeder connection point to another.<\/p>\n<p>Under normal operating conditions, Feeder A energizes the cable to RMU 1 and continues to RMU 2. Feeder B energizes the cable to RMU 3. The normally open point between RMU 2 and RMU 3 breaks the through-path at that point on the cable route. RMU 2 and RMU 3 are both energized from their respective sides, but that cable tie is open. This does not establish that their upstream sources are electrically independent. The two feeder labels \u2014 A and B \u2014 do not by themselves imply that the two sources are independent in the sense of coming from separate generation facilities or separate grid entry points. The labels identify the two cable segments. Source diversity is a network-level design question beyond the RMU itself.<\/p>\n<figure class=\"wp-block-image size-full\" data-media-role=\"inline\"><img class=\"wp-image-1803\" src=\"https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig02-final-11.webp\" alt=\"Feeder A connects to RMUs 1 and 2. Feeder B connects to RMU 3. An open gap separates RMUs 2 and 3.\" width=\"1536\" height=\"1024\" loading=\"lazy\" decoding=\"async\" srcset=\"https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig02-final-11.webp 1536w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig02-final-11-300x200.webp 300w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig02-final-11-1024x683.webp 1024w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig02-final-11-768x512.webp 768w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig02-final-11-18x12.webp 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><figcaption>In the normal state, the open point separates the two feeder paths.<\/figcaption><\/figure>\n<p>The normally open point is provided by a designated device at a position chosen in the network design, considering loading and operating requirements. A particular RMU need not house it. The gap drawn between RMU 2 and RMU 3 is a schematic representation of the open connection; the actual drawing must identify the switch or other rated device that creates it.<\/p>\n<p>The contrast with a plain radial network is worth stating directly. A simple radial feeder without an alternate tie has one supply route to its downstream substations. If that route is interrupted by a cable fault, it has no planned cable path around the fault in this comparison. The ring topology, with its physical loop and designed open point, creates the geometric precondition for an alternative path \u2014 but whether that path can actually be used depends on the network being engineered to use it, with appropriate capacity and protection.<\/p>\n<p><a href=\"https:\/\/www.electrical-installation.org\/enwiki\/Internal_MV_circuits\" target=\"_blank\" rel=\"noopener\">Schneider Electric\u2019s internal MV circuit examples<\/a> compare radial and ring layouts.<\/p>\n<p><!-- SUBIA:SUPPLEMENTARY-VIDEO-START --><\/p>\n<style>.subia-article-article .subia-supplementary-video{margin:2em 0;max-width:100%;min-width:0}.subia-supplementary-video__frame{position:relative;width:100%;aspect-ratio:16\/9;min-height:200px;background:#111;overflow:hidden}.subia-supplementary-video__frame iframe{position:absolute;inset:0;display:block;width:100%;height:100%;max-width:100%;border:0}.subia-article-article .subia-supplementary-video figcaption{font-size:.9em;line-height:1.6;color:#555;margin-top:.7em;overflow-wrap:anywhere}\n.subia-supplementary-video__cover{position:absolute;inset:0;width:100%;height:100%;display:grid;place-items:center;cursor:pointer;border:0;padding:0;border-radius:0;background:#111;color:white}\n.subia-supplementary-video__cover img{position:absolute;inset:0;display:block;width:100%;height:100%;max-width:none;object-fit:cover;margin:0}\n.subia-supplementary-video__cover:focus-visible{outline:3px solid white;outline-offset:-5px}\n.subia-supplementary-video__icon{position:relative;z-index:1;display:grid;place-items:center;width:64px;height:44px;border-radius:10px;background:#c9172c;box-shadow:0 2px 12px #0008}\n.subia-supplementary-video__cover:hover .subia-supplementary-video__icon{background:#a71122}\n.subia-supplementary-video__icon::after{content:\"\";border-block:9px solid transparent;border-left:15px solid white;margin-left:3px}<\/style>\n<figure class=\"subia-supplementary-video\" id=\"supplementary-video\">\n<div class=\"subia-supplementary-video__frame\"><button type=\"button\" class=\"subia-supplementary-video__cover\" aria-label=\"Play video: What is Ring Main Unit (RMU) | Explained | TheElectricalGuy\" data-video-title=\"What is Ring Main Unit (RMU) | Explained | TheElectricalGuy\" data-video-embed=\"https:\/\/www.youtube-nocookie.com\/embed\/cEqkngScig0?rel=0&amp;start=228&amp;end=480&amp;autoplay=1&amp;playsinline=1\"><img src=\"https:\/\/i.ytimg.com\/vi\/cEqkngScig0\/hqdefault.jpg\" width=\"480\" height=\"360\" alt=\"\" loading=\"lazy\" decoding=\"async\" fetchpriority=\"low\"><span class=\"subia-supplementary-video__icon\" aria-hidden=\"true\"><\/span><\/button><\/div><figcaption>Follow a ring-main network and see where the RMU fits in the distribution arrangement.<\/figcaption><\/figure>\n<p><script class=\"subia-video-activation\">(() => {\n  const figure = document.getElementById('supplementary-video');\n  const cover = figure?.querySelector('.subia-supplementary-video__cover');\n  if (!cover) return;\n  cover.addEventListener('click', () => {\n    const player = document.createElement('iframe');\n    player.title = cover.dataset.videoTitle;\n    player.width = '960';\n    player.height = '540';\n    player.referrerPolicy = 'strict-origin-when-cross-origin';\n    player.allow = 'autoplay; encrypted-media; picture-in-picture; fullscreen';\n    player.allowFullscreen = true;\n    player.src = cover.dataset.videoEmbed;\n    const hadFocus = document.activeElement === cover;\n    cover.replaceWith(player);\n    if (hadFocus) player.focus({ preventScroll: true });\n  }, { once: true });\n})();<\/script><br \/>\n<script type=\"application\/ld+json\" class=\"subia-video-schema\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"VideoObject\",\"@id\":\"https:\/\/subiapower.com\/what-is-a-ring-main-unit-rmu-how-it-works-in-secondary-distribution\/#supplementary-video\",\"name\":\"What is Ring Main Unit (RMU) | Explained | TheElectricalGuy\",\"description\":\"Follow a ring-main network and see where the RMU fits in the distribution arrangement.\",\"thumbnailUrl\":\"https:\/\/i.ytimg.com\/vi\/cEqkngScig0\/hqdefault.jpg\",\"embedUrl\":\"https:\/\/www.youtube-nocookie.com\/embed\/cEqkngScig0?rel=0&start=228&end=480\",\"isPartOf\":{\"@id\":\"https:\/\/subiapower.com\/what-is-a-ring-main-unit-rmu-how-it-works-in-secondary-distribution\/#webpage\"},\"uploadDate\":\"2023-11-02\",\"duration\":\"PT1185S\"}<\/script><br \/>\n<!-- SUBIA:SUPPLEMENTARY-VIDEO-END --><\/p>\n<h2>What Changes After a Cable Fault<\/h2>\n<p>Using the same three-substation arrangement, consider a cable fault occurring in the section between RMU 1 and RMU 2. Before the fault, this section carries supply from Feeder A toward RMU 2. The resulting fault can trip the feeder and interrupt both substations supplied from that side until the network is reconfigured.<\/p>\n<p>In this example, fault current is interrupted by the upstream feeder breaker, not by the load-break ring ways alone. This is a key distinction. An RMU&#8217;s load-break ring way can open and close under load, but interrupting actual fault current requires a suitable protective device, typically located at the feeder circuit breaker upstream. The ring ways provide the sectionalizing points. In the isolated network state shown, the way at RMU 1 facing RMU 2 and the way at RMU 2 facing RMU 1 are both open, leaving the faulted cable outside the restored supply paths at both ends. The faulted section remains out of service. This describes the diagram\u2019s state, rather than the operator\u2019s switching or fault-location procedure.<\/p>\n<h2>How Supply Can Be Restored After Cable Fault Isolation<\/h2>\n<p>In the possible restored state, Feeder A again supplies RMU 1 from its original direction. The cable between RMU 1 and RMU 2 remains isolated and out of service. The former normally open point between RMU 2 and RMU 3 is closed in this state, so Feeder B supplies both RMU 3 and RMU 2 through the alternate route. RMU 2\u2019s transformer regains supply through its transformer way, now fed from the Feeder B direction via RMU 3. The drawing does not imply uninterrupted service during the fault and restoration.<\/p>\n<figure class=\"wp-block-image size-full\" data-media-role=\"inline\"><img class=\"wp-image-1804\" src=\"https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig03-final-11.webp\" alt=\"Feeder A connects to RMU 1, and Feeder B connects to RMUs 3 and 2. The cable between RMUs 1 and 2 is disconnected at both ends.\" width=\"1536\" height=\"1024\" loading=\"lazy\" decoding=\"async\" srcset=\"https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig03-final-11.webp 1536w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig03-final-11-300x200.webp 300w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig03-final-11-1024x683.webp 1024w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig03-final-11-768x512.webp 768w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig03-final-11-18x12.webp 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><figcaption>In this restored state, Feeder B supplies RMU 2 through the former open point while the damaged cable remains isolated.<\/figcaption><\/figure>\n<p><a href=\"https:\/\/pilbara.prod-cms12.horizonpower.com.au\/globalassets\/media\/documents\/manuals-standards\/switching-operators-manual-process-and-rules\/switching-operators-manual---distribution.pdf#page=148\" target=\"_blank\" rel=\"noopener\">Horizon Power\u2019s distribution manual<\/a> documents utility sectionalizing and alternate-feed concepts.<\/p>\n<p>This outcome has conditions that must be satisfied before it can happen. The feeder from which the alternate supply comes needs sufficient capacity to carry the transferred load in addition to its existing load. Protection coordination must be acceptable for the new supply arrangement. And the network must be engineered and authorized for this type of reconfiguration. Alternate-feed planning, as illustrated in <a href=\"https:\/\/www.xcelenergy.com\/staticfiles\/xe-responsive\/Company\/Rates%20%26%20Regulations\/21-0694%20Integrated%20Distribution%20Plan%20110121%20NSP%20PUBLIC_COMPLETE.pdf#page=66\" target=\"_blank\" rel=\"noopener\">Xcel Energy\u2019s distribution plan<\/a>, explicitly accounts for feeder loading when determining whether a normally open tie can carry the transferred load.<\/p>\n<p>No switching procedure is implied here, and no guarantee of continuity follows from the topology. The illustration shows what the network allows when the conditions are right \u2014 healthy cables, available capacity, acceptable protection coordination, and an approved operating arrangement. Automation of the switching sequence is a separate system option that requires additional equipment and is not inherent to the RMU itself.<\/p>\n<h2>What to Confirm on the Single-Line Diagram<\/h2>\n<p>Before specifying or procuring an RMU, the project single-line diagram needs to resolve four distinct areas.<\/p>\n<figure class=\"wp-block-image size-full\" data-media-role=\"inline\"><img class=\"wp-image-1805\" src=\"https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig04-final-11.webp\" alt=\"Four cards show the network drawing, equipment ratings, feeder protection and cable interfaces.\" width=\"1536\" height=\"1024\" loading=\"lazy\" decoding=\"async\" srcset=\"https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig04-final-11.webp 1536w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig04-final-11-300x200.webp 300w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig04-final-11-1024x683.webp 1024w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig04-final-11-768x512.webp 768w, https:\/\/subiapower.com\/wp-content\/uploads\/2026\/11\/fig04-final-11-18x12.webp 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><figcaption>Use the project drawing and equipment schedule together to define the duty of each way.<\/figcaption><\/figure>\n<p><strong>Network drawing.<\/strong> Mark each way and its normal state on the project drawing. Identify which ring way faces which cable direction, which way connects to the transformer, and where the normally open point sits in the ring. An ambiguous drawing leads to incorrect specification \u2014 for example, treating a ring-way position as a transformer-way position, or specifying a plain load-break where protection is needed.<\/p>\n<p><strong>Equipment ratings.<\/strong> Each way in the RMU carries a duty defined by the project: voltage level, continuous current rating, and short-circuit duties. Making, short-time withstand and breaking ratings describe different functions; a load-break ring way does not need to be described as a fault interrupter merely because it has a short-circuit making or withstand rating. The project network study determines these figures; they are not interchangeable between different positions on the ring or between different voltage levels. The specific ratings for a given way must be verified against what the project network study requires, not assumed from a product family designation.<\/p>\n<h2>Transformer Feeder Protection and Cable Interfaces<\/h2>\n<p><strong>Feeder protection.<\/strong> Identify the transformer way protection arrangement that the network protection coordination requires. A coordinated switch-fuse combination provides its specified protective and switching functions. A circuit breaker with a suitable relay can provide selected protective characteristics and tripping functions; remote control requires the specified mechanisms, auxiliary supply and interfaces. Neither protection label alone proves which automation features are included. The choice is a protection engineering question, not simply a preference, and the selected arrangement must be coordinated with the upstream feeder protection.<\/p>\n<p><a href=\"https:\/\/library.e.abb.com\/public\/9fd3ed5c1b184898b9c06c470a1c769f\/SafeRing_SafePlus%2012_24kV_Catalogue_EN_1YVA000022_REV%20C-VI%2003-2023_web_link_26.03.16.pdf#page=21\" target=\"_blank\" rel=\"noopener\">ABB\u2019s SafeRing catalogue<\/a> gives transformer-feeder examples using a switch-fuse combination or a breaker and relay.<\/p>\n<p><strong>Cable interfaces.<\/strong> The cable termination arrangement at each way \u2014 conductor size, insulation level, cable entry direction, termination type \u2014 must match the project cable specification and the switchgear&#8217;s cable box design. Site interfaces, including space for cable bending radius, earthing arrangements, and access for termination and testing, need to be confirmed before equipment is ordered.<\/p>\n<p>Remote indication and control \u2014 position feedback, remote alarm, or remote switching \u2014 are options that add to the electrical and communication interface requirements. If the project requires them, they belong in the specification. If they are not part of the present operating plan, consider their cost, interface work and any planned future use explicitly rather than treating them as automatic requirements. Remote monitoring capability does not equate to automatic fault restoration; that is a system-level function requiring additional equipment and engineering beyond the RMU itself.<\/p>\n<p>For further reference on MV switchgear types and ring-network configurations relevant to secondary distribution, SUBIA&#8217;s <a href=\"https:\/\/subiapower.com\/high-low-voltage-distribution-equipment\/medium-voltage-switchgear\/\">Medium Voltage Switchgear<\/a> page covers available assembly options including ring network switchgear. For the broader equipment package at a secondary substation, <a href=\"https:\/\/subiapower.com\/what-is-a-prefabricated-substation-components-and-power-flow\/\">What Is a Prefabricated Substation?<\/a> covers the relationship between the switchgear, transformer, and enclosure. For general switchgear terminology, <a href=\"https:\/\/subiapower.com\/what-is-electrical-switchgear-functions-components-and-types\/\">What Is Electrical Switchgear?<\/a> provides a foundation for the assembly-level distinctions used throughout this article.<\/p>\n<p>When comparing proposals, keep the protection arrangement and the individual making, withstand and breaking duties as separate review items. One nominal voltage or product-family label does not answer all of them.<\/p>\n<h2>Frequently Asked Questions<\/h2>\n<h3>What is the difference between an RMU and a transformer?<\/h3>\n<p>An RMU switches MV circuits and can include protection for a transformer feeder. The transformer changes voltage between its connected circuits.<\/p>\n<h3>Do both feeders run in parallel in a normally open ring?<\/h3>\n<p>The normal open point breaks the electrical connection between the two feeder sections at that location. Each section has its own normal feed path in the illustrated arrangement.<\/p>\n<h3>Can an RMU keep every substation supplied during a cable fault?<\/h3>\n<p>An open ring can give healthy sections an alternate feed path after the faulted section is isolated. An outage can still occur. Restoration depends on available capacity, protection and the approved network arrangement.<\/p>\n<h3>Do all RMUs use the same transformer feeder protection?<\/h3>\n<p>Transformer feeder protection depends on the project. Examples include a coordinated switch-fuse combination and a circuit breaker with a protection relay. Verify the selected arrangement against the project protection requirements.<\/p>\n<p><!-- SUBIA:FAQ-END --><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Gu\u00eda ilustrada sobre las v\u00edas de circuito de la RMU, un anillo normalmente abierto y la ruta de alimentaci\u00f3n alternativa tras el aislamiento del cable.<\/p>","protected":false},"author":1,"featured_media":1801,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-1806","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technical-resources"],"blocksy_meta":{"has_hero_section":"enabled","hero_section":"type-2","disable_featured_image":"yes","page_title_bg_type":"featured_image","page_title_image_size":"full","hero_structure":"narrow","hero_elements":[{"id":"custom_title","enabled":true,"heading_tag":"h1"},{"id":"custom_description","enabled":false},{"id":"custom_meta","enabled":false},{"id":"breadcrumbs","enabled":false}],"styles_descriptor":{"styles":{"desktop":"[data-prefix=\"single_blog_post\"] .entry-header .page-title {--theme-font-size:30px;} [data-prefix=\"single_blog_post\"] .entry-header .entry-meta {--theme-font-weight:600;--theme-text-transform:uppercase;--theme-font-size:12px;--theme-line-height:1.3;} [data-prefix=\"single_blog_post\"] .hero-section[data-type=\"type-2\"] {background-color:var(--theme-palette-color-6);background-image:none;--container-padding:50px 0px;}","tablet":"","mobile":""},"google_fonts":{"Lexend":["n4","n6"]},"version":7}},"_links":{"self":[{"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/posts\/1806","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/comments?post=1806"}],"version-history":[{"count":5,"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/posts\/1806\/revisions"}],"predecessor-version":[{"id":2439,"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/posts\/1806\/revisions\/2439"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/media\/1801"}],"wp:attachment":[{"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/media?parent=1806"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/categories?post=1806"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/subiapower.com\/es\/wp-json\/wp\/v2\/tags?post=1806"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}