{"product_id":"square-d-ljf36400u31x-400a-600v-3-pole-bolt-on-circuit-breaker","title":"Square D LJF36400U31X - 400 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState","description":"\u003cdiv\u003e\n\u003cp\u003eThe Square D LJF36400U31X is a rugged, three-pole bolt-on molded case circuit breaker designed for dependable branch circuit overcurrent and short-circuit protection in panelboards and loadcenters. With a 400 A rating and a 600 V capability, this device is built to handle demanding power distribution in commercial and light industrial settings, while still suitable for select residential applications that require higher load handling.\u003c\/p\u003e \u003ch3\u003eKey advantages that matter in the field\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eSecure bolt-on mounting\u003c\/strong\u003e provides a rigid, vibration-resistant bus connection, helping maintain consistent electrical contact in environments with movement or vibration.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThermal-magnetic trip unit\u003c\/strong\u003e delivers stable, repeatable protection by responding to both overload and short-circuit conditions, helping prevent nuisance tripping while preserving equipment uptime.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eOEM-compatible design\u003c\/strong\u003e ensures reliable fit and performance with matching load centers and panelboards, reducing installation fit issues and ensuring coordinated protection.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eHigh-capacity protection\u003c\/strong\u003e 400 A at 600 V, three poles, ideal for main or feeder protection in larger distribution schemes and multi-branch circuits.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVersatile applications\u003c\/strong\u003e suited for residential, commercial, and light industrial environments where robust, code-compliant overcurrent protection is required.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eTechnical snapshot\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003eManufacturer: Square D\u003c\/li\u003e \u003cli\u003ePart Number: LJF36400U31X\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: Bolt-on\u003c\/li\u003e \u003cli\u003eApplication: Branch circuit overcurrent and short-circuit protection\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eWho benefits from this breaker\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003eFacilities with large panelboards and loadcenters that require strong main or feeder protection\u003c\/li\u003e \u003cli\u003eElectrical installations in commercial spaces, light industrial facilities, and multi-family residences needing reliable three-phase protection\u003c\/li\u003e \u003cli\u003eTechnicians seeking a durable, OEM-compatible solution to replace aging or failed breakers in Square D systems\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003ePractical considerations and use scenarios\u003c\/h3\u003e\n\u003cp\u003eInstall the LJF36400U31X in panelboards and loadcenters designed for bolt-on molded case breakers to ensure optimal contact and performance. Its thermal-magnetic trip mechanism provides predictable protection behavior under varying load conditions, reducing unexpected outages. When planning installation, verify compatibility with the existing OEM enclosure and ensure the mounting hardware and bus connections remain secure to maintain long-term reliability.\u003c\/p\u003e \u003ch3\u003eWhy this matters in your power distribution system\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003eReliable protection for critical equipment and circuits helps minimize downtime and potential damage from overcurrent events.\u003c\/li\u003e \u003cli\u003eThe combination of bolt-on mounting and a robust thermal-magnetic trip unit supports consistent protection performance even in environments with vibration or mechanical stress.\u003c\/li\u003e \u003cli\u003eOEM compatibility simplifies replacements and maintenance, preserving system coordination and reducing retrofit challenges.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Amp State","offers":[{"title":"Default Title","offer_id":46355326369954,"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_060e5b4e-a6a8-4de0-9cf0-a954540e2b31.png?v=1764691353","url":"https:\/\/www.ampstate.com\/products\/square-d-ljf36400u31x-400a-600v-3-pole-bolt-on-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}