{"product_id":"square-d-ljp36400u31x-circuit-breaker","title":"Square D | LJP36400U31X | Circuit Breaker | 400A | 3-Pole","description":"\u003cdiv\u003e\n\u003cp\u003e\u003cstrong\u003eSquare D LJP36400U31X\u003c\/strong\u003e is a 400A, 3-pole circuit breaker engineered for maintenance, retrofit, and replacement projects where exact specifications matter. As a genuine Square D part, it brings the reliability and compatibility you expect from premium electrical distribution equipment.\u003c\/p\u003e \u003cp\u003eKey reasons to choose this model:\u003c\/p\u003e \u003cul\u003e \u003cli\u003e\n\u003cstrong\u003ePrecise compatibility by part number\u003c\/strong\u003e — LJP36400U31X is the best reference for ensuring your new breaker matches the ratings and mounting geometry of your existing system. Always verify that the fit and ratings align with your panel’s documentation before ordering.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eHigh-current capacity\u003c\/strong\u003e — 400A continuous rating supports heavy feeders and high-load applications in commercial and industrial environments.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThree-pole protection\u003c\/strong\u003e — provides balanced protection across all phases in a 3-phase electrical system, helping maintain system stability and protecting equipment.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eDesigned for maintenance, retrofit, and replacement\u003c\/strong\u003e — ideal for refreshing aging panels, upgrading capacity, or replacing a worn-out breaker in compatible Square D installations.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eTrustworthy Square D engineering\u003c\/strong\u003e — backed by Schneider Electric’s legacy of durable, safe, and standards-compliant electrical products.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003ePractical notes for installers\u003c\/strong\u003e — Confirm fit and ratings against the equipment label or service data; keep the part number handy for future reference and part replacements.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eWhat problems does it solve?\u003c\/h3\u003e \u003cp\u003eThis breaker helps maintain uninterrupted power distribution by providing reliable, compatible protection for high-demand circuits. By matching the exact 400A, 3-pole specifications and using the correct part number, you minimize the risk of incompatibility, mounting issues, or protection gaps that can occur with off-brand or mismatched components.\u003c\/p\u003e \u003ch3\u003eIdeal use cases\u003c\/h3\u003e \u003cul\u003e \u003cli\u003eRetrofits in existing Square D panels that require a 400A, 3-pole breaker to support higher loads\u003c\/li\u003e \u003cli\u003eMaintenance and replacement of aging distribution equipment in commercial or light-industrial settings\u003c\/li\u003e \u003cli\u003eUpgrades where system design calls for a precise 400A, 3-pole configuration with proven Square D compatibility\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eHow it compares to alternatives\u003c\/h3\u003e \u003cp\u003eChoosing the exact part number (LJP36400U31X) matters for compatibility of mounting, electrical characteristics, and warranty alignment. Unlike generic or third-party replacements, this Square D unit is engineered to fit your panel and maintain consistent protection across all phases, reducing the likelihood of fitment issues and post-install adjustments.\u003c\/p\u003e \u003ch3\u003ePractical tips\u003c\/h3\u003e \u003cul\u003e \u003cli\u003eKeep the \u003cstrong\u003epart number LJP36400U31X\u003c\/strong\u003e on hand as the primary reference when sourcing replacements or performing panel documentation updates.\u003c\/li\u003e \u003cli\u003eDouble-check your panel’s labeling and service manual to confirm that a 3-pole 400A device is listed as an approved replacement.\u003c\/li\u003e \u003cli\u003eStore replacement breakers in a clean, dry environment to prevent corrosion or wear before installation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Square D","offers":[{"title":"Default Title","offer_id":46424800985250,"sku":"LJP36400U31X","price":310.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/8094\/6850\/files\/square-d-ljp36400u31x-circuit-breaker-400a-3-pole-578.webp?v=1789415410","url":"https:\/\/www.ampstate.com\/products\/square-d-ljp36400u31x-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}