{"product_id":"square-d-lja36400u43x-400a-600v-3-pole-plug-in-circuit-breaker","title":"Square D LJA36400U43X - 400 A, 600 V, 3-Pole Plug-In Circuit Breaker | AmpState","description":"\u003cdiv\u003e\n\u003cp\u003eSquare D LJA36400U43X is a 400 A, 600 V, 3-pole plug-in molded case circuit breaker designed to deliver reliable branch circuit protection in panelboards and load centers. Built for demanding electrical environments, it provides sturdy, fast-acting protection you can count on in everyday commercial and light industrial settings.\u003c\/p\u003e \u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eFast plug-in connection\u003c\/strong\u003e for quick installation and effortless replacement, minimizing panel downtime during upgrades or service calls.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThermal-magnetic trip unit\u003c\/strong\u003e combines precise thermal protection with immediate short-circuit interruption, delivering stable, repeatable protection performance across varying loads.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eOEM-ready compatibility\u003c\/strong\u003e designed to fit matching Square D load centers and panelboards, helping ensure a seamless, dependable fit with your existing equipment.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVersatile application\u003c\/strong\u003e suitable for residential, commercial, and light industrial environments where robust branch-circuit overcurrent and short-circuit protection is essential.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eWhat this means in real-world scenarios\u003c\/h3\u003e\n\u003cp\u003eIf you’re upgrading a panel or replacing an aging breaker, the LJA36400U43X provides a straightforward plug-in installation that keeps systems online with minimal fuss. Its 400 A rating supports larger branch circuits, while the 3-pole design is ideal for three-phase panel configurations common in commercial facilities. The 600 V rating covers a wide range of standard electrical systems, giving you flexibility for future expansion without swapping components.\u003c\/p\u003e \u003ch3\u003eKey specifications at a glance\u003c\/h3\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 LJA36400U43X\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 400 A\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVoltage rating:\u003c\/strong\u003e 600 V\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 \u003ch3\u003eWho it's for and how it stacks up\u003c\/h3\u003e\n\u003cp\u003eIdeal for facilities managers, electrical contractors, and maintenance teams tackling panelboard upgrades or new installations in commercial and light industrial spaces. This breaker emphasizes quick, field-friendly replacement with reliability backed by Square D’s thermal-magnetic protection framework, reducing nuisance trips and ensuring dependable operation under diverse load conditions. Its plug-in design and OEM compatibility mean fewer compatibility concerns and a smoother installation process compared to non-plug or cross-compatible alternatives.\u003c\/p\u003e \u003cp\u003eTips for installation and use: ensure the target panelboard is designed for plug-in molded case breakers of this type, verify three-phase configuration aligns with your system, and follow standard safety practices during replacement or maintenance. For longer-term reliability, pair with matching Square D load centers to preserve protection coordination and system performance.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Amp State","offers":[{"title":"Default Title","offer_id":46355324993698,"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_cb4ee737-4d7f-476b-96a0-9599f6393efe.png?v=1764691346","url":"https:\/\/www.ampstate.com\/products\/square-d-lja36400u43x-400a-600v-3-pole-plug-in-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}