{"product_id":"square-d-lda36400u43x-400a-3-pole-plug-in-circuit-breaker","title":"Square D LDA36400U43X - 400 A, 3-Pole Plug-In Circuit Breaker | AmpState","description":"\u003cdiv\u003e\n\u003cp\u003eThe Square D LDA36400U43X is a 400 A, 3-pole plug-in molded case circuit breaker designed to protect your panelboards and loadcenters from overcurrent and short-circuit events. Engineered for dependable performance in residential, commercial, and light industrial environments, this breaker delivers quick installation and robust, consistent protection when it matters most.\u003c\/p\u003e \u003ch2\u003eWhy this breaker stands out\u003c\/h2\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eFast plug-in connection\u003c\/strong\u003e for streamlined installation and effortless replacements, minimizing downtime during upgrades or service calls.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThermal-magnetic trip unit\u003c\/strong\u003e provides stable, repeatable protection by combining thermal overload sensing with magnetic short-circuit tripping—balancing sensitivity and reliability.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eOEM panelboard compatibility\u003c\/strong\u003e engineered to fit and function with matching Square D loadcenters and panelboards, ensuring seamless integration and labeling consistency.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eHigh-current, three-phase protection\u003c\/strong\u003e suited for large residential feeders, commercial equipment, and light industrial circuits requiring 400 A capacity.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003ePlug-in molded case design\u003c\/strong\u003e offers durable enclosure protection and easy field service, ideal for panelboard upgrades and maintenance.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eTechnical snapshot\u003c\/h2\u003e\n\u003cul\u003e \u003cli\u003eManufacturer: Square D\u003c\/li\u003e \u003cli\u003ePart Number: LDA36400U43X\u003c\/li\u003e \u003cli\u003eType: Thermal-magnetic molded case circuit breaker\u003c\/li\u003e \u003cli\u003eAmperage Rating: 400 A\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 in panelboards and loadcenters\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eIdeal applications and use cases\u003c\/h2\u003e\n\u003cp\u003eUse this 3-pole, 400 A plug-in breaker to safeguard three-phase equipment and large feeders in residential complexes, commercial offices, retail centers, or light industrial facilities. It’s well-suited for main distribution panels where high-current protection is required, as well as subpanels feeding motor loads, HVAC equipment, or heavy electrical circuits. When you need reliable protection with quick replacement in OEM-aligned panels, this Square D breaker is a precise fit.\u003c\/p\u003e \u003ch2\u003eInstallation and maintenance tips\u003c\/h2\u003e\n\u003cp\u003eTo get the most from the LDA36400U43X, ensure you’re installing it in a panelboard or loadcenter that accepts Square D plug-in molded case breakers and that the panel’s rating supports a 400 A, 3-pole device. Rely on the fast plug-in connection to minimize outage time during upgrades or service work, and rely on the thermal-magnetic trip to maintain consistent protection against both overloads and short circuits. Regularly inspect panel labeling to confirm compatibility and ensure proper alignment with the bus stabs for reliable operation.\u003c\/p\u003e \u003ch2\u003eWhy AmpState supports this choice\u003c\/h2\u003e\n\u003cp\u003eAs a trusted source for genuine Square D components, AmpState provides access to authentic LDA36400U43X breakers along with trusted support for selecting the right protection devices for your panelboard or loadcenter. With compatibility, performance, and installation efficiency in mind, this 400 A, 3-pole plug-in breaker is a practical, reliable solution for demanding electrical protection needs.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Amp State","offers":[{"title":"Default Title","offer_id":46355320832162,"sku":null,"price":710.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/8094\/6850\/files\/square-d-lda36400u43x-400-a-3-pole-plug-in-circuit-breaker-ampstate-420.webp?v=1788750131","url":"https:\/\/www.ampstate.com\/products\/square-d-lda36400u43x-400a-3-pole-plug-in-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}