{"id":33599,"date":"2026-09-16T07:18:06","date_gmt":"2026-09-16T07:18:06","guid":{"rendered":"https:\/\/fenchenergy.com\/?post_type=product&p=33599"},"modified":"2026-10-26T01:21:02","modified_gmt":"2026-10-26T01:21:02","slug":"300a-dc-circuit-breaker-mccb-diy-battery-box","status":"publish","type":"product","link":"https:\/\/fenchenergy.com\/sl\/product\/300a-dc-circuit-breaker-mccb-diy-battery-box\/","title":{"rendered":"300A DC odklopnik MCCB za DIY baterijske \u0161katle | 2-polni baterijski izolator, zaloga EU"},"content":{"rendered":"
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A 300A DC circuit breaker does one job your BMS cannot do on its own: it gives you a physical break in the circuit.<\/strong> Va\u0161 BMS \u0161\u010diti celice pred prekomernim tokom in kratkimi stiki, vendar ko morate delati na paketu, izolirati inverter ali izklopiti napajanje v sili, potrebujete nekaj, kar lahko dejansko izklopite. Ta 2-polni DC odklopnik sedi med va\u0161o baterijo in inverterjem, doda za\u0161\u010dito pred kratkim stikom poleg BMS in vam daje vidno to\u010dko za odklop.<\/p>

Why a 300A DC Circuit Breaker Beats Relying on the BMS Alone<\/h3>

BMS je za\u0161\u010ditna naprava, ne stikalo. Prekine tok, ko nekaj ni v redu, vendar vam ne omogo\u010da, da po potrebi izolirate paket \u2014 in ne bo odpravil trdega kratkega stika na glavni DC napajalni liniji tako kot odklopnik. Dodajanje odklopnika vam prinese tri stvari, ki jih BMS sam ne more:<\/p>

  • Ro\u010dni odklop<\/strong> za vzdr\u017eevanje, nadgradnje in nujne primere<\/li>
  • Odpravljanje kratkega stika<\/strong> ocenjeno na 7,5kA<\/li>
  • Napaka, ki jo lahko vidite<\/strong> \u2014 spro\u017een odklopnik vam poka\u017ee, da se je nekaj zgodilo, namesto da bi vas pustil ugibati<\/li><\/ul>

    AC odklopniki ne sodijo v baterijsko vezje<\/h4>

    To je najve\u010dja napaka. Izmeni\u010dni tok prehaja skozi ni\u010dlo 50-60 krat na sekundo, in ta ni\u010delni prehod omogo\u010da AC odklopniku, da ugasne oblok, ko se spro\u017ei. Enosmerni tok nima ni\u010delnega prehoda, zato oblok \u0161e naprej gori. AC odklopnik lahko ne uspe odpraviti napake v baterijskem sistemu, kar je prav situacija, ki jo mora odklopnik re\u0161iti.<\/p>

    Choosing a 300A DC Circuit Breaker for High-Output Systems<\/h3>

    300A is the top of this series. Choose it when your system genuinely runs at that level:<\/p>

    • You run a 300A BMS<\/strong><\/li>
    • You have an inverter drawing close to the BMS limit<\/strong> on a continuous basis<\/li>
    • You are running more than one inverter<\/strong>, or plan to add one<\/li>
    • Your load profile is high and sustained<\/strong> rather than short bursts<\/li>
    • You want no margin compromise<\/strong> \u2014 the breaker stays above everything downstream<\/li><\/ul>
      Your BMS \/ system<\/th>Model to choose<\/th><\/tr><\/thead>
      200A BMS \u2014 the standard DIY build<\/td>BCPS2DM220, 220A<\/td><\/tr>
      250A BMS, or 200A BMS with surge-heavy loads<\/td>BCPS2DM250, 250A<\/td><\/tr>
      300A BMS in sistemi z visoko mo\u010djo<\/strong><\/td>BCPS2DM300 \u2014 this model, 300A<\/strong><\/td><\/tr><\/tbody><\/table><\/div><\/div>

      One warning that matters more than the table: at 300A the cable becomes the bottleneck.<\/strong> A 300A breaker does not make an undersized cable safe \u2014 size the cable for the current first, and make sure your terminals and busbars are rated for it too.<\/p>

      Branje etikete: DC ocena in zmogljivost prekinjanja<\/h3>
      Marking<\/th>What it means<\/th><\/tr><\/thead>
      125\/250V DC<\/strong><\/td>DC voltage rating \u2014 125V per pole, 250V with both poles<\/td><\/tr>
      2P<\/strong><\/td>Two poles, breaking together<\/td><\/tr>
      300A<\/strong><\/td>Rated continuous current<\/td><\/tr>
      Icu\/Ics 7.5kA<\/strong><\/td>Short-circuit breaking capacity<\/td><\/tr>
      IEC 60947-2<\/strong><\/td>The switchgear standard the device is marked to<\/td><\/tr><\/tbody><\/table><\/div><\/div>

      Fitting a DC Circuit Breaker Into a DIY Battery Box<\/h3>

      At 78 \u00d7 38 \u00d7 63mm and 225g, this breaker fits inside a battery enclosure or a tight cabinet instead of needing its own panel.<\/p>

      1. Mount it where you can reach it.<\/strong> A breaker you cannot access is decoration.<\/li>
      2. Follow the LINE and LOAD markings<\/strong>, and confirm the wiring diagram in the manual before connecting.<\/li>
      3. Torque the terminals to spec<\/strong> and re-check after the first thermal cycle.<\/li>
      4. Keep AC and DC separate.<\/strong> This device goes on the DC side between battery and inverter; the AC output side needs its own AC breakers.<\/li>
      5. Check heat at full load.<\/strong> High-current builds warm up; leave airflow around the breaker and check terminal temperature after the first hour at full load.<\/li><\/ol>

        Specifikacije<\/h3>
        Parameter<\/th>Specifikacija<\/th><\/tr><\/thead>
        Model<\/td>BCPS2DM300<\/td><\/tr>
        Tip<\/td>2-pole DC circuit breaker (MCCB)<\/td><\/tr>
        Rated current<\/td>300A<\/td><\/tr>
        Voltage rating<\/td>125\/250V DC<\/td><\/tr>
        Breaking capacity<\/td>Icu\/Ics 7.5kA<\/td><\/tr>
        Poles<\/td>2<\/td><\/tr>
        Dimenzije<\/td>78 \u00d7 38 \u00d7 63mm<\/td><\/tr>
        Te\u017ea<\/td>225g<\/td><\/tr>
        Application<\/td>Short-circuit protection and manual isolation for battery boxes<\/td><\/tr>
        Standard marking<\/td>IEC 60947-2<\/td><\/tr>
        OEM \/ ODM<\/td>Supported<\/td><\/tr>
        Po\u0161iljanje<\/td>Zaloga v EU, dostava DDP iz Poljske<\/td><\/tr><\/tbody><\/table><\/div><\/div>

        Ni vklju\u010deno:<\/strong> the battery box, the BMS and the battery cells. This listing is the circuit breaker only.<\/p>

        Pogosta vpra\u0161anja<\/h3>

        Which systems need a 300A DC circuit breaker?<\/strong>
        300A BMS builds, systems with inverter loads running close to the BMS limit, and installations with more than one inverter.<\/p>

        Can I use a smaller breaker to save money?<\/strong>
        No. A breaker rated below your system’s continuous current will nuisance-trip. Size at or just above your continuous current.<\/p>

        Can I use an AC breaker on a battery circuit instead?<\/strong>
        No. DC arcs do not self-extinguish, so an AC breaker may fail to clear a fault. This device is DC-rated at 125\/250V DC.<\/p>

        How much short-circuit current can it clear?<\/strong>
        7.5kA (Icu\/Ics).<\/p>

        Will it fit inside my battery box?<\/strong>
        At 78 \u00d7 38 \u00d7 63mm and 225g it fits most DIY enclosures. Send us the mounting space if you are unsure.<\/p>

        Do you make other ratings?<\/strong>
        Yes \u2014 220A (BCPS2DM220) and 250A (BCPS2DM250) in the same series.<\/p>

        Does it come with the box, BMS or cells?<\/strong>
        No. This listing is the breaker only.<\/p>

        Related: Battery Box Parts and Accessories<\/h3>

        Building a complete pack? Pair the breaker with a DIY battery box kit, a battery box base, a set of battery box wheels, and a JK BMS heating pad if you charge in cold weather. Cells in 280Ah, 314Ah and 320Ah are available from the same warehouse.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"

        \ud83d\udd0c 300A DC Circuit Breaker MCCB \u2014 2-Pole Battery Isolator<\/strong>
        \n\u2705 DC ocenjeno 2-polno stikalo za DIY baterijske \u0161katle | 125\/250V DC
        \n\u26a1 300A rated | Icu\/Ics 7.5kA short-circuit breaking capacity
        \n\ud83d\udd17 For 300A BMS builds and high-output systems
        \n\ud83d\udcd0 Kompaktno 78 \u00d7 38 \u00d7 63mm | 225g | namesti se znotraj ohi\u0161ja
        \n\u26a0\ufe0f Samo odklopnik \u2014 \u0161katla, BMS in celice NISO vklju\u010dene
        \n\ud83d\ude9a Zaloga EU | Skladi\u0161\u010de na Poljskem<\/p>","protected":false},"featured_media":33607,"comment_status":"open","ping_status":"closed","template":"","meta":[],"product_brand":[],"product_cat":[305],"product_tag":[],"class_list":["post-33599","product","type-product","status-publish","has-post-thumbnail","product_cat-accessories-parts","first","instock","shipping-taxable","purchasable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/product\/33599","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/comments?post=33599"}],"version-history":[{"count":1,"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/product\/33599\/revisions"}],"predecessor-version":[{"id":34238,"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/product\/33599\/revisions\/34238"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/media\/33607"}],"wp:attachment":[{"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/media?parent=33599"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/product_brand?post=33599"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/product_cat?post=33599"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/fenchenergy.com\/sl\/wp-json\/wp\/v2\/product_tag?post=33599"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}