{"product_id":"square-d-mja36300-300a-600v-3-pole-plug-in-circuit-breaker","title":"Square D MJA36300 - 300 A, 600 V, 3-Pole Plug-In Circuit Breaker | AmpState","description":"\u003cdiv\u003e\n\u003cp\u003eEngineered for dependable branch circuit protection, the Square D MJA36300 is a 300A, 600V, three-pole plug-in molded case circuit breaker designed to drop into compatible panelboards and load centers with ease. Built to perform in demanding commercial and light industrial environments, it delivers fast installation, reliable protection, and long service life where it truly matters—the safety of your electrical distribution.\u003c\/p\u003e \u003ch2\u003eKey advantages\u003c\/h2\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003ePlug-in convenience:\u003c\/strong\u003e Fast plug-in connection enables quick installation and rapid replacement when maintenance or upgrades are needed, minimizing downtime.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThermal-magnetic protection:\u003c\/strong\u003e A thermal-magnetic trip unit provides stable, repeatable overcurrent and short-circuit protection, helping to prevent nuisance trips while safeguarding wiring and equipment.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eOEM-compatible:\u003c\/strong\u003e Carefully designed to be fully compatible with matching Square D OEM load centers and panelboards for a seamless fit and coordinated protection strategy.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVersatile power handling:\u003c\/strong\u003e With a 600V rating and a 3-pole configuration, it supports three-phase circuits commonly found in commercial and light industrial applications.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eApplications and use cases\u003c\/h2\u003e\n\u003cp\u003eIdeal for panelboard upgrades, new installations, or field replacements in facilities where reliability is key. Suitable for protecting feeders and branch circuits serving HVAC equipment, lighting and power distribution, pumps, conveyors, and other 3‑phase loads in small to mid-size commercial and light industrial settings. The plug-in design simplifies serviceability in crowded panels, reducing project timelines and downtime.\u003c\/p\u003e \u003ch2\u003eWhy choose the MJA36300\u003c\/h2\u003e\n\u003cul\u003e \u003cli\u003eReliable protection for critical circuits with a focus on stable trip performance and quick restoration after a fault.\u003c\/li\u003e \u003cli\u003eEliminates compatibility guesswork by aligning with matching OEM panelboards and load centers.\u003c\/li\u003e \u003cli\u003eDesigned to withstand the rigors of everyday electrical distribution in commercial and light industrial environments.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eTechnical snapshot\u003c\/h2\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Square D\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e MJA36300\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Thermal-magnetic molded case circuit breaker\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eAmperage Rating:\u003c\/strong\u003e 300A\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVoltage Rating:\u003c\/strong\u003e 600V\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eNumber of Poles:\u003c\/strong\u003e 3\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eMounting Style:\u003c\/strong\u003e Plug-in\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Branch circuit overcurrent and short-circuit protection\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003eWhen you’re upgrading a panel or provisioning a new commercial or light industrial installation, the Square D MJA36300 delivers a plug‑in, three‑pole solution that combines rapid serviceability with dependable protection. It’s the practical, compatible choice for safeguarding your electrical distribution while keeping downtime to a minimum.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Amp State","offers":[{"title":"Default Title","offer_id":46355347767458,"sku":null,"price":710.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/8094\/6850\/files\/schnieder_and_square_d_breaker_and_panel_d8d96073-6ab2-439e-859d-705ea99e9c12.png?v=1764691456","url":"https:\/\/www.ampstate.com\/products\/square-d-mja36300-300a-600v-3-pole-plug-in-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}