{"id":6787,"date":"2026-10-19T13:17:34","date_gmt":"2026-10-19T13:17:34","guid":{"rendered":"https:\/\/www.pvlinktech.com\/?p=6787"},"modified":"2026-10-20T09:49:43","modified_gmt":"2026-10-20T09:49:43","slug":"conector-de-derivacao-mc4-y","status":"publish","type":"post","link":"https:\/\/www.pvlinktech.com\/pt\/mc4-y-branch-connector\/","title":{"rendered":"Conector em Y MC4 ou caixa combinadora: qual \u00e9 a op\u00e7\u00e3o ideal para o painel?"},"content":{"rendered":"\n<div class=\"wp-block-greenshift-blocks-image gspb_image gspb_image-id-gsbp-0e6dc77\" id=\"gspb_image-id-gsbp-0e6dc77\"><img decoding=\"async\" src=\"https:\/\/www.pvlinktech.com\/wp-content\/uploads\/2026\/10\/Solar-Cable-Connections-on-Gravel.webp\" data-src=\"\" alt=\"MC4 Y branch connector installed at the array where two strings are paralleled\" loading=\"lazy\" width=\"1536\" height=\"1024\"\/><\/div>\n\n\n\n\n\n<h1 id=\"gspb_heading-id-gsbp-28dc719\" class=\"gspb_heading gspb_heading-id-gsbp-28dc719 \">MC4 Y Branch Connector or Combiner Box: Which Fits the Array?<\/h1>\n\n\n\n<!-- =========================================\nPVLinkTech | Technical Blog Info Bar\nWordPress + Blocksy Compatible\nResponsive | Scoped CSS\n========================================= -->\n\n<style>\n  .pv-tech-note,\n  .pv-tech-note *,\n  .pv-tech-note *::before,\n  .pv-tech-note *::after {\n    box-sizing: border-box;\n  }\n\n  .pv-tech-note {\n    --pv-blue: #0057B8;\n    --pv-green: #5ACB2E;\n    --pv-text: #334155;\n    --pv-border: #E3EAF1;\n\n    width: 100%;\n    margin: 0;\n    padding: 0 20px;\n\n    font-family:\n      Inter,\n      -apple-system,\n      BlinkMacSystemFont,\n      \"Segoe UI\",\n      Roboto,\n      Helvetica,\n      Arial,\n      sans-serif;\n  }\n\n  .pv-tech-note .pv-tech-note-inner {\n    position: relative;\n    display: flex;\n    flex-wrap: wrap;\n    align-items: center;\n    gap: 4px 10px;\n\n    width: 100%;\n    max-width: 1400px;\n    margin: 0 auto;\n    padding: 8px 18px;\n\n 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}\n\n  .pv-tech-note .pv-tech-note-label:hover {\n    color: #FFFFFF;\n    background: #00458F;\n    border-color: #00458F;\n    text-decoration: none;\n    box-shadow: 0 5px 12px rgba(0, 69, 143, 0.24);\n    transform: translateY(-1px);\n  }\n\n  .pv-tech-note .pv-tech-note-label:active {\n    transform: translateY(0);\n    box-shadow: 0 1px 3px rgba(0, 69, 143, 0.18);\n  }\n\n  .pv-tech-note .pv-tech-note-label:focus-visible {\n    outline: 2px solid var(--pv-blue);\n    outline-offset: 3px;\n  }\n\n  \/* Visual separators *\/\n  .pv-tech-note .pv-tech-note-separator {\n    color: #94A3B8;\n    font-weight: 400;\n    flex: 0 0 auto;\n  }\n\n  \/* Supporting description *\/\n  .pv-tech-note .pv-tech-note-text {\n    color: #475569;\n    font-weight: 400;\n  }\n\n  \/* Editorial review statement *\/\n  .pv-tech-note .pv-tech-note-review {\n    color: var(--pv-blue);\n    font-weight: 500;\n  }\n\n  \/* Clearly visible Peter Wang profile link *\/\n  .pv-tech-note .pv-tech-note-review a,\n  .pv-tech-note .pv-tech-note-review a:visited {\n    display: inline;\n    color: var(--pv-blue) !important;\n    font-weight: 700;\n    text-decoration: underline;\n    text-decoration-color: var(--pv-green);\n    text-decoration-thickness: 2px;\n    text-underline-offset: 3px;\n    transition:\n      color 0.2s ease,\n      text-decoration-color 0.2s ease;\n  }\n\n  \/* Hover effect *\/\n  .pv-tech-note .pv-tech-note-review a:hover,\n  .pv-tech-note .pv-tech-note-review a:focus-visible {\n    color: var(--pv-green) !important;\n    text-decoration-color: var(--pv-green);\n  }\n\n  .pv-tech-note .pv-tech-note-review a:focus-visible {\n    outline: 2px solid var(--pv-blue);\n    outline-offset: 3px;\n  }\n\n  \/* Tablet and mobile *\/\n  @media (max-width: 768px) {\n    .pv-tech-note {\n      padding-right: 14px;\n      padding-left: 14px;\n    }\n\n    .pv-tech-note .pv-tech-note-inner {\n      gap: 3px 7px;\n      padding: 7px 14px;\n      border-radius: 7px;\n      font-size: 13px;\n      line-height: 1.65;\n    }\n\n    .pv-tech-note .pv-tech-note-label,\n    .pv-tech-note .pv-tech-note-text,\n    .pv-tech-note .pv-tech-note-review {\n      white-space: normal;\n    }\n\n    .pv-tech-note .pv-tech-note-label {\n      padding: 5px 11px;\n      font-size: 12.5px;\n    }\n  }\n\n  \/* Small mobile screens *\/\n  @media (max-width: 480px) {\n    .pv-tech-note {\n      padding-right: 12px;\n      padding-left: 12px;\n    }\n\n    .pv-tech-note .pv-tech-note-inner {\n      gap: 3px 6px;\n      padding: 6px 12px;\n      font-size: 12.5px;\n      line-height: 1.7;\n    }\n  }\n<\/style>\n\n<aside class=\"pv-tech-note\" aria-label=\"PVLinkTech technical blog information\">\n  <div class=\"pv-tech-note-inner\">\n\n    <!-- Technical Blog link -->\n    <a class=\"pv-tech-note-label\" href=\"https:\/\/www.pvlinktech.com\/blog\/\">\n      PVLinkTech Technical Blog <span aria-hidden=\"true\">\u2192<\/span>\n    <\/a>\n\n    <span class=\"pv-tech-note-separator\" aria-hidden=\"true\">\u00b7<\/span>\n\n    <!-- Content description -->\n    <span class=\"pv-tech-note-text\">\n      Guides for Buyers, Mechanical Designers and Procurement Teams\n    <\/span>\n\n    <span class=\"pv-tech-note-separator\" aria-hidden=\"true\">\u00b7<\/span>\n\n    <!-- Technical reviewer with clickable profile -->\n    <span class=\"pv-tech-note-review\">\n      Reviewed by\n      <a href=\"https:\/\/www.pvlinktech.com\/peter-wang\/\" aria-label=\"View Peter Wang's profile\">Peter Wang<\/a>, Technical Director, PVLinkTech\n    <\/span>\n\n    <span class=\"pv-tech-note-separator\" aria-hidden=\"true\">\u00b7<\/span>\n\n    <!-- Last updated date -->\n    <span class=\"pv-tech-note-text\">\n      Updated <time datetime=\"2026-10\">2026-10<\/time>\n    <\/span>\n\n  <\/div>\n<\/aside>\n\n\n\n<p class=\"wp-block-paragraph\">An MC4 Y branch connector parallels two strings at the array instead of routing them to a combiner box. Whether that is allowed is a fault-current question before it is a cost question, because a Y branch carries no fusing and cannot be opened under load. It is only appropriate where the paralleled conductors can survive the current the neighbouring strings can feed into a fault. Work that out first, and the choice between a branch connector and a combiner box usually makes itself.<\/p>\n\n\n\n<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><h2>Table of Contents<\/h2><nav><ul><li><a href=\"#gspb_heading-id-gsbp-28dc719\">MC4 Y Branch Connector or Combiner Box: Which Fits the Array?<\/a><ul><li><a href=\"#short-answer\">Short answer<\/a><\/li><li><a href=\"#undefined-1\">What an MC4 Y branch connector actually does<\/a><\/li><li><a href=\"#undefined-2\">The fault current reason combiners exist<\/a><\/li><li><a href=\"#undefined-3\">When a Y branch is the right choice<\/a><\/li><li><a href=\"#undefined-4\">When you need a combiner box<\/a><\/li><li><a href=\"#undefined-5\">Choosing between them<\/a><\/li><li><a href=\"#undefined-6\">What the two options cost you in the field<\/a><\/li><li><a href=\"#undefined-7\">The sizing check that catches people out<\/a><\/li><li><a href=\"#undefined-8\">What to specify<\/a><\/li><li><a href=\"#undefined-9\">Mistakes worth avoiding<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n\n\n\n<h2 id=\"short-answer\" class=\"wp-block-heading\">Short answer<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A Y branch suits two strings, where the design current stays inside the connector rating and the code you are inspected to permits paralleling without per-string protection. A combiner box takes over as soon as three or more strings are paralleled, where each string needs overcurrent protection, or where the array needs a disconnect point or monitoring. The crossover sits around the second to third string, and it is set by fault current rather than by array size.<\/p>\n\n\n\n<h2 id=\"undefined-1\" class=\"wp-block-heading\">What an MC4 Y branch connector actually does<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">Term<\/th><th class=\"has-text-align-left\" data-align=\"left\">What it means here<\/th><\/tr><\/thead><tbody><tr><td>Branch connector<\/td><td>Paralleled connectors at the array, one input splitting into two outputs or the reverse<\/td><\/tr><tr><td>String<\/td><td>A series run of modules whose voltage adds and whose current does not<\/td><\/tr><tr><td>Isc<\/td><td>Short-circuit current of one string, from the module datasheet<\/td><\/tr><tr><td>Back-feed<\/td><td>Current a faulted string receives from the parallel strings<\/td><\/tr><tr><td>Continuous-duty factor<\/td><td>The multiplier a code applies to Isc when sizing conductors and protection, commonly 1.25<\/td><\/tr><tr><td>Combiner box<\/td><td>An enclosure with per-string protection, and usually a disconnect<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The electrical difference between the two is simple to state. A branch connector is a mechanical joint that happens to parallel two circuits. A combiner box is a protective device that also happens to parallel them, and the rest of the comparison follows from that difference.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Configurations vary with the array. A common form of MC4 Y branch connector splits one input into two outputs, used where a single home-run cable serves two paralleled strings. The reverse, two inputs combining into one output, appears where two strings land on one cable running to the inverter. Which one you need is decided by where the paralleling happens, not by the connector itself, and the pole and keying arrangement has to match the rest of the string.<\/p>\n\n\n\n<h2 id=\"undefined-2\" class=\"wp-block-heading\">The fault current reason combiners exist<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In a single string, a short circuit is fed by the string&#8217;s own Isc. On a modern module that is around 13.5 A, and the module leads and connector are built to carry that current without difficulty.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Parallel two strings and the arithmetic changes. If one string faults, the healthy string feeds current into the fault as well as contributing its own. With three strings, the other two feed the fault. The faulted conductors now have to carry that combined current, and they were sized for one string.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">Strings in parallel<\/th><th class=\"has-text-align-left\" data-align=\"left\">Combined Isc<\/th><th class=\"has-text-align-left\" data-align=\"left\">Back-feed into one faulted string<\/th><\/tr><\/thead><tbody><tr><td>1<\/td><td>13.5 A<\/td><td>none<\/td><\/tr><tr><td>2<\/td><td>27.0 A<\/td><td>13.5 A<\/td><\/tr><tr><td>3<\/td><td>40.5 A<\/td><td>27.0 A<\/td><\/tr><tr><td>4<\/td><td>54.0 A<\/td><td>40.5 A<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">This is why most PV installation codes require overcurrent protection on each string once three or more are paralleled. A&nbsp;<a href=\"https:\/\/en.wikipedia.org\/wiki\/Electrical_fuse\" target=\"_blank\" rel=\"noopener\">fuse<\/a>&nbsp;interrupts the back-feed before the faulted conductor is damaged. Fuses need a place to live, and that place is a combiner box. A Y branch has nowhere to put them, which is the whole reason the two products exist side by side rather than one replacing the other.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For two strings, protection is often not required, provided the conductors can carry the total available fault current. That condition has to be verified against the module datasheet and the code that applies, not assumed, and it is the single check that decides whether a Y branch is permitted at all.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Where protection is required, its rating comes from the module rather than from the connector. Each module datasheet publishes a maximum series fuse rating, typically in the 15 to 25 A range on modern modules, and that figure sets what the string protection has to be. A connector rated above the module&#8217;s fuse rating does not remove the requirement. It only means the connector is not the limiting component.<\/p>\n\n\n\n<h2 id=\"undefined-3\" class=\"wp-block-heading\">When a Y branch is the right choice<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Two strings only<\/strong>, and the conductors verified against the combined fault current.<\/li>\n\n\n\n<li><strong>No need for a disconnect<\/strong>&nbsp;at that point in the array.<\/li>\n\n\n\n<li><strong>Weight and space matter.<\/strong>&nbsp;On a rooftop or a floating array, removing an enclosure from the bill of materials is a real saving in mounting hardware and labor.<\/li>\n\n\n\n<li><strong>The junction is permanent.<\/strong>&nbsp;Nothing about the design expects someone to isolate one string at that point later.<\/li>\n\n\n\n<li><strong>Cost sensitivity at the string level.<\/strong>&nbsp;Two branch connectors cost a fraction of an enclosure with fuses and a disconnect.<\/li>\n<\/ul>\n\n\n\n<h2 id=\"undefined-4\" class=\"wp-block-heading\">When you need a combiner box<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Three or more strings<\/strong>, where per-string protection is required and a branch connector has nowhere to mount a fuse.<\/li>\n\n\n\n<li><strong>A disconnect is needed<\/strong>&nbsp;for service or for the inverter&#8217;s isolation procedure.<\/li>\n\n\n\n<li><strong>Monitoring or string-level metering<\/strong>&nbsp;is part of the specification.<\/li>\n\n\n\n<li><strong>The joint must be serviceable.<\/strong>&nbsp;A combiner box gives each string its own entry and can be opened without cutting cable.<\/li>\n\n\n\n<li><strong>Cable management is a factor.<\/strong>&nbsp;Six strings landing on three branch connectors is a harder installation to keep tidy and to inspect than one enclosure with glands.<\/li>\n<\/ul>\n\n\n\n<h2 id=\"undefined-5\" class=\"wp-block-heading\">Choosing between them<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">If the situation is<\/th><th class=\"has-text-align-left\" data-align=\"left\">Use<\/th><th class=\"has-text-align-left\" data-align=\"left\">Why<\/th><\/tr><\/thead><tbody><tr><td>Two strings, conductors verified for fault current<\/td><td>Y branch<\/td><td>No protection required, no enclosure to mount<\/td><\/tr><tr><td>Three or more strings<\/td><td>Combiner box<\/td><td>Per-string fusing required, nowhere else to put it<\/td><\/tr><tr><td>Two strings but a disconnect is specified<\/td><td>Combiner box<\/td><td>The enclosure carries the disconnect<\/td><\/tr><tr><td>Rooftop or floating, weight is critical<\/td><td>Y branch, if permitted<\/td><td>Removes an enclosure and its mounting hardware<\/td><\/tr><tr><td>Local code requires per-string protection<\/td><td>Combiner box<\/td><td>Code requirement, not a preference<\/td><\/tr><tr><td>Combined current above the connector rating<\/td><td>Re-design<\/td><td>See the sizing calculation below<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 id=\"undefined-6\" class=\"wp-block-heading\">What the two options cost you in the field<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A branch connector adds two mated pairs where there was one joint. Both are contact interfaces with their own resistance, and both are points where a partially engaged half can go unnoticed. That is not a reason to avoid the part, but it does raise the installation discipline around it: each pair has to be fully latched, and the assembly needs support so the weight of the cables does not pull on the joints.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A combiner box moves the joints inside an enclosure, where they are protected and can be inspected. It also needs a mounting point, a gland per cable, and clearance for the door to open. On a rail-mounted rooftop array, that mounting point is sometimes the thing that decides the layout.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The saving from a branch connector is real at the home run. Paralleling at the array halves the number of cables returning to the inverter, and on a long DC run that reduces both copper and voltage drop. Where the array already sits close to the inverter, the saving is small and the enclosure is the simpler build.<\/p>\n\n\n\n<h2 id=\"undefined-7\" class=\"wp-block-heading\">The sizing check that catches people out<\/h2>\n\n\n\n<div class=\"wp-block-greenshift-blocks-image gspb_image gspb_image-id-gsbp-8ffc75a\" id=\"gspb_image-id-gsbp-8ffc75a\"><img decoding=\"async\" src=\"https:\/\/www.pvlinktech.com\/wp-content\/uploads\/2026\/10\/bf5be39c8e5ea9d058cf611d81a7322a.webp\" data-src=\"\" alt=\"Chart comparing combined string current against a 30 A connector rating for one to four paralleled strings\" loading=\"lazy\" width=\"1200\" height=\"700\"\/><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">Adding up Isc is not enough. Conductors and protection are sized on Isc multiplied by a continuous-duty factor, commonly 1.25 in PV circuits, because a module can sit at or above its rated output for hours.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th class=\"has-text-align-left\" data-align=\"left\">Strings in parallel<\/th><th class=\"has-text-align-left\" data-align=\"left\">Combined Isc<\/th><th class=\"has-text-align-left\" data-align=\"left\">After a 1.25 factor<\/th><th class=\"has-text-align-left\" data-align=\"left\">Fits a 30 A connector?<\/th><\/tr><\/thead><tbody><tr><td>1<\/td><td>13.5 A<\/td><td>16.9 A<\/td><td>Yes<\/td><\/tr><tr><td>2<\/td><td>27.0 A<\/td><td>33.8 A<\/td><td>**No**<\/td><\/tr><tr><td>3<\/td><td>40.5 A<\/td><td>50.6 A<\/td><td>No<\/td><\/tr><tr><td>4<\/td><td>54.0 A<\/td><td>67.5 A<\/td><td>No<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The second row is the one worth reading twice. Two strings of a modern 13.5 A module come to 33.8 A once the factor is applied, which is already above a 30 A connector rating. That does not automatically prohibit an MC4 Y branch connector in every jurisdiction, because the factor applied to a connector is not identical everywhere, but it does mean the assumption that the part comfortably handles two modern strings is wrong often enough to be worth checking every time. Older modules with lower Isc left more headroom, and a lot of field practice was learned on those.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For background on how protection is applied to DC circuits generally, see the&nbsp;<a href=\"https:\/\/en.wikipedia.org\/wiki\/Overcurrent\" target=\"_blank\" rel=\"noopener\">overcurrent<\/a>&nbsp;reference. If your two-string case lands close to or above the rating, the honest options are a lower-current module configuration, a larger branch assembly, or a combiner box. Adding a bigger connector to a branch that the rest of the string cannot match does not help.<\/p>\n\n\n\n<h2 id=\"undefined-8\" class=\"wp-block-heading\">What to specify<\/h2>\n\n\n\n<div class=\"wp-block-greenshift-blocks-image gspb_image gspb_image-id-gsbp-bc8a8ac\" id=\"gspb_image-id-gsbp-bc8a8ac\"><img decoding=\"async\" src=\"https:\/\/www.pvlinktech.com\/wp-content\/uploads\/2026\/10\/Industrial-Solar-Cable-Connectors-with-Orange-O-Ring.webp\" data-src=\"\" alt=\"MC4 connector pair used to build Y branch assemblies for parallel PV strings\" loading=\"lazy\" width=\"1536\" height=\"1024\"\/><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">Whether you are buying a branch connector or specifying a combiner box, the same information drives the quote:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Number of strings to be paralleled, and the configuration needed<\/li>\n\n\n\n<li>Module Isc and the maximum series fuse rating from the datasheet<\/li>\n\n\n\n<li>System maximum voltage, 1000 V or 1500 V<\/li>\n\n\n\n<li>Conductor cross-section and cable jacket outer diameter<\/li>\n\n\n\n<li>Whether the joint has to be disconnectable under load<\/li>\n\n\n\n<li>The code or standard the installation is inspected to<\/li>\n\n\n\n<li>Any certification or interoperability requirement between connector brands<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Branch assemblies are produced as a project item rather than held as a catalogue part, because the configuration depends on the array. That suits the way arrays are actually specified, but it does mean the string data has to be supplied before the part can be confirmed. Our&nbsp;<a href=\"https:\/\/www.pvlinktech.com\/custom-waterproof-connector-manufacturer\/\">custom connector<\/a>&nbsp;process covers how a project like this runs, from DFM review through sample validation, and the&nbsp;<a href=\"https:\/\/www.pvlinktech.com\/mc4-pv4-solar-connectors\/\">MC4 solar connector<\/a>&nbsp;page gives the ratings of the connector family these assemblies are built from.<\/p>\n\n\n\n<h2 id=\"undefined-9\" class=\"wp-block-heading\">Mistakes worth avoiding<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Counting strings and stopping there.<\/strong>&nbsp;The factor on top of Isc is what decides whether the connector is adequate.<\/li>\n\n\n\n<li><strong>Assuming two strings never need protection.<\/strong>&nbsp;Verify against the datasheet and the applicable code rather than against habit.<\/li>\n\n\n\n<li><strong>Putting a Y branch where a disconnect is required.<\/strong>&nbsp;A branch connector cannot be opened under load.<\/li>\n\n\n\n<li><strong>Mixing connector brands in a branch assembly.<\/strong>&nbsp;Uncertified pairs can end up with mismatched contact resistance under the combined current.<\/li>\n\n\n\n<li><strong>Sizing the branch on the inverter input rating.<\/strong>&nbsp;The relevant current is at the branch, not at the inverter.<\/li>\n\n\n\n<li><strong>Forgetting the fuse rating.<\/strong>&nbsp;Where protection is required, it is set by the module&#8217;s maximum series fuse rating, not by the connector.<\/li>\n<\/ul>\n\n\n\n<style>\n\/* ================================\n   PVLinkTech FAQ - Blocksy Compatible\n   Colors:\n   Blue  #0057B8\n   Green #5ACB2E\n================================ *\/\n\n.pvlt-faq-section {\n    width: 100%;\n    max-width: 1200px;\n    margin: 0 auto;\n    padding: 10px 20px 50px;\n    box-sizing: border-box;\n    font-family: inherit;\n    color: #1f2933;\n}\n\n.pvlt-faq-heading {\n    margin: 0 0 26px;\n    padding: 0;\n}\n\n.pvlt-faq-heading h2 {\n    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ease;\n}\n\n.pvlt-faq-button:hover {\n    background: #00478f;\n    color: #ffffff !important;\n    transform: translateY(-1px);\n    box-shadow: 0 5px 14px rgba(0, 87, 184, 0.18);\n}\n\n.pvlt-faq-button:focus-visible {\n    outline: 3px solid rgba(90, 203, 46, 0.45);\n    outline-offset: 3px;\n}\n\n\/* ================================\n   Mobile\n================================ *\/\n\n@media (max-width: 767px) {\n\n    .pvlt-faq-section {\n        padding: 5px 15px 35px;\n    }\n\n    .pvlt-faq-heading {\n        margin-bottom: 20px;\n    }\n\n    .pvlt-faq-heading h2 {\n        font-size: 28px;\n    }\n\n    .pvlt-faq-list {\n        gap: 9px;\n    }\n\n    .pvlt-faq-question {\n        padding: 17px 17px;\n        gap: 14px;\n        font-size: 16px;\n        line-height: 1.45;\n    }\n\n    .pvlt-faq-question::after {\n        width: 28px;\n        height: 28px;\n        font-size: 20px;\n    }\n\n    .pvlt-faq-answer {\n        padding: 0 17px 19px;\n        font-size: 15px;\n        line-height: 1.7;\n    }\n\n    .pvlt-faq-cta {\n        margin-top: 28px;\n        padding: 25px 21px;\n    }\n\n    .pvlt-faq-cta-title {\n        font-size: 19px;\n    }\n\n    .pvlt-faq-cta-text {\n        font-size: 15px;\n        line-height: 1.65;\n    }\n\n    .pvlt-faq-button {\n        width: 100%;\n        min-height: 48px;\n    }\n}\n\n\/* ================================\n   Accessibility\n================================ *\/\n\n.pvlt-faq-question:focus-visible {\n    outline: 3px solid rgba(90, 203, 46, 0.45);\n    outline-offset: -3px;\n}\n<\/style>\n\n\n<section class=\"pvlt-faq-section\" aria-labelledby=\"pvlt-faq-title\">\n\n    <div class=\"pvlt-faq-heading\">\n        <h2 id=\"pvlt-faq-title\">FAQ<\/h2>\n    <\/div>\n\n    <div class=\"pvlt-faq-list\">\n\n        <!-- FAQ 1 -->\n        <details class=\"pvlt-faq-item\" open>\n            <summary class=\"pvlt-faq-question\">\n                What is an MC4 Y branch connector used for?\n            <\/summary>\n\n            <div class=\"pvlt-faq-answer\">\n                <p>\n                    It parallels two PV strings at the array, replacing one combiner box\n                    and its fuses where the paralleling is permitted without per-string\n                    protection and no disconnect is required at that point.\n                <\/p>\n            <\/div>\n        <\/details>\n\n\n        <!-- FAQ 2 -->\n        <details class=\"pvlt-faq-item\">\n            <summary class=\"pvlt-faq-question\">\n                Can I parallel more than two strings with branch connectors?\n            <\/summary>\n\n            <div class=\"pvlt-faq-answer\">\n                <p>\n                    Generally no. Once three or more strings are paralleled, most codes\n                    require overcurrent protection on each string, and a branch connector\n                    has no place to mount a fuse. That points to a combiner box.\n                <\/p>\n            <\/div>\n        <\/details>\n\n\n        <!-- FAQ 3 -->\n        <details class=\"pvlt-faq-item\">\n            <summary class=\"pvlt-faq-question\">\n                How do I know whether two strings can be paralleled without fuses?\n            <\/summary>\n\n            <div class=\"pvlt-faq-answer\">\n                <p>\n                    Check whether the conductors can carry the total available fault\n                    current, applying the continuous-duty factor your code requires,\n                    and confirm against the module datasheet and local requirements.\n                    It is a verification, not a rule of thumb.\n                <\/p>\n            <\/div>\n        <\/details>\n\n\n        <!-- FAQ 4 -->\n        <details class=\"pvlt-faq-item\">\n            <summary class=\"pvlt-faq-question\">\n                Why does the continuous-duty factor matter for a connector?\n            <\/summary>\n\n            <div class=\"pvlt-faq-answer\">\n                <p>\n                    Because PV circuits can sit at or near rated output for hours,\n                    code sizing applies a multiplier, commonly 1.25, to Isc.\n                    Two modern 13.5 A strings come to 33.8 A after that factor,\n                    which is above a 30 A connector rating.\n                <\/p>\n            <\/div>\n        <\/details>\n\n\n        <!-- FAQ 5 -->\n        <details class=\"pvlt-faq-item\">\n            <summary class=\"pvlt-faq-question\">\n                Can I use branch connectors to reduce cable runs to the inverter?\n            <\/summary>\n\n            <div class=\"pvlt-faq-answer\">\n                <p>\n                    They reduce the number of home-run cables by paralleling at the\n                    array, but they do not remove the need for protection where it is\n                    required, so the saving applies only to the permitted two-string case.\n                <\/p>\n            <\/div>\n        <\/details>\n\n\n        <!-- FAQ 6 -->\n        <details class=\"pvlt-faq-item\">\n            <summary class=\"pvlt-faq-question\">\n                Are branch assemblies available with different connector configurations?\n            <\/summary>\n\n            <div class=\"pvlt-faq-answer\">\n                <p>\n                    Yes, and they are produced to the array rather than as a stocked\n                    catalogue item, so the configuration is confirmed against the\n                    string count, module data and conductor size before the part is quoted.\n                    Certification documents for the connector family are in our\n                    <a href=\"https:\/\/www.pvlinktech.com\/certificates\/\">\n                        certificates\n                    <\/a>\n                    section.\n                <\/p>\n            <\/div>\n        <\/details>\n\n    <\/div>\n\n\n    <!-- CTA -->\n    <div class=\"pvlt-faq-cta\">\n\n        <h3 class=\"pvlt-faq-cta-title\">\n            Get the right branch configuration for the array.\n        <\/h3>\n\n        <p class=\"pvlt-faq-cta-text\">\n            Send us the string count, module Isc, maximum series fuse rating,\n            system voltage and conductor size, and we will confirm the configuration,\n            tell you whether the paralleling is suitable for a branch assembly or\n            needs a combiner, and arrange samples for validation.\n        <\/p>\n\n        <a class=\"pvlt-faq-button\" href=\"https:\/\/www.pvlinktech.com\/waterproof-connector-quote\/\">\n            Request a Quote\n        <\/a>\n\n    <\/div>\n\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>PVLinkTech Technical Blog \u2192 \u00b7 Guides for Buyers, Mechanical Designers and Procurement Teams \u00b7 Reviewed by Peter Wang, Technical Director, PVLinkTech \u00b7 Updated 2026-10 An MC4 Y branch connector parallels two strings at the array instead of routing them to a combiner box. Whether that is allowed is a fault-current question before it is a [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":6792,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_gspb_post_css":"#gspb_image-id-gsbp-0e6dc77 img,#gspb_image-id-gsbp-8ffc75a img,#gspb_image-id-gsbp-bc8a8ac img{vertical-align:top;display:inline-block;box-sizing:border-box;max-width:100%;height:auto}","footnotes":""},"categories":[1],"tags":[],"class_list":["post-6787","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-solar-connector-guides"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/posts\/6787","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/comments?post=6787"}],"version-history":[{"count":0,"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/posts\/6787\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/media\/6792"}],"wp:attachment":[{"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/media?parent=6787"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/categories?post=6787"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pvlinktech.com\/pt\/wp-json\/wp\/v2\/tags?post=6787"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}