{"product_id":"square-d-lja36400u44x-400a-600v-3-pole-plug-in-circuit-breaker","title":"Square D LJA36400U44X - 400 A, 600 V, 3-Pole Plug-In Circuit Breaker | AmpState","description":"\u003cdiv\u003e\n\u003cp\u003eThe Square D LJA36400U44X stands out as a robust, plug-in molded case circuit breaker designed to protect your distribution panels with precision. Rated at 400 A and 600 V, this 3-pole unit delivers dependable branch-circuit overcurrent and short-circuit protection for panelboards and loadcenters in demanding environments.\u003c\/p\u003e \u003cp\u003e\u003cstrong\u003eKey advantages that matter in the real world\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eFast plug-in connection\u003c\/strong\u003e for quick installation and hassle-free replacement, minimizing downtime during panel servicing or upgrades.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThermal-magnetic trip unit\u003c\/strong\u003e delivers stable, repeatable protection—responding to overloads and short circuits with predictable performance to keep equipment safe.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eOEM-compatible design\u003c\/strong\u003e ensures seamless compatibility with matching Square D load centers and panelboards, reducing installation guesswork and ensuring reliable busbar connections.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eHigh-current, three-phase protection\u003c\/strong\u003e with 3-pole construction suits three-phase systems and heavy-duty loads common in commercial and light industrial applications.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVersatile applications\u003c\/strong\u003e suitable for residential, commercial, and light industrial environments, offering flexibility across project types and building sizes.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eWhy this model might be the right choice for your panel\u003c\/h3\u003e\n\u003cp\u003eIf you’re upgrading or replacing a protection device in a Square D panelboard, the LJA36400U44X provides a precise fit and reliable performance. Its 400 A rating makes it appropriate for main or feeder protection in medium-duty electrical distributions, while the 600 V rating covers standard commercial and light industrial circuits. The plug-in mounting simplifies service routines and reduces the risk of loose connections that can lead to arcing or nuisance tripping.\u003c\/p\u003e \u003cp\u003e\u003cstrong\u003eWho benefits most\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e \u003cli\u003eElectrical contractors responsible for maintaining commercial or industrial panels.\u003c\/li\u003e \u003cli\u003eFacility maintenance teams replacing aging protection devices in panelboards and load centers.\u003c\/li\u003e \u003cli\u003eDistributors stocking OEM-compatible breakers for quick customer turnarounds.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003e\u003cstrong\u003ePractical use cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e \u003cli\u003eReplacing a failed or obsolete trip unit in a 3-phase panelboard serving heavy machinery or HVAC systems.\u003c\/li\u003e \u003cli\u003eUpgrading an older protection scheme to a modern 400 A, 3-pole plug-in breaker in a commercial distribution center.\u003c\/li\u003e \u003cli\u003eInstalling in new or renovated facilities where a reliable 3-pole, 400 A main feeder is required within a 600 V electrical system.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003e\u003cstrong\u003eTechnical specifications at a glance\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e \u003cli\u003eManufacturer: Square D\u003c\/li\u003e \u003cli\u003ePart Number: LJA36400U44X\u003c\/li\u003e \u003cli\u003eType: Thermal-magnetic molded case circuit breaker\u003c\/li\u003e \u003cli\u003eAmperage Rating: 400 A\u003c\/li\u003e \u003cli\u003eVoltage Rating: 600 V\u003c\/li\u003e \u003cli\u003eNumber of Poles: 3\u003c\/li\u003e \u003cli\u003eMounting Style: Plug-in\u003c\/li\u003e \u003cli\u003eApplication: Branch circuit overcurrent and short-circuit protection\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003eFor reliable protection that aligns with your distribution equipment, the Square D LJA36400U44X delivers precise performance with a straightforward installation path. It’s a practical, industry-standard choice for protecting essential circuits in panelboards and loadcenters, helping you maintain system uptime and electrical safety with confidence.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Amp State","offers":[{"title":"Default Title","offer_id":46355325026466,"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_8f244e8b-8110-4300-903e-3b3e415931b4.png?v=1764691347","url":"https:\/\/www.ampstate.com\/products\/square-d-lja36400u44x-400a-600v-3-pole-plug-in-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}