{"product_id":"square-d-q1l390-90a-3p-circuit-breaker","title":"Square D Q1L390 90A 3P Circuit Breaker, Plug-On | AmpState","description":"\u003cdiv\u003e\n\u003cp\u003eIntroducing the Square D Q1L390 90A 3P Circuit Breaker, Plug-On from AmpState—a genuine Square D device engineered to guard panelboards, load centers, and electrical distribution networks with precise, reliable protection. Designed for replacement projects and as a ready-to-swap spare, the Q1L390 helps you keep your BOM aligned with the original part number for smooth maintenance and upgrades.\u003c\/p\u003e \u003cp\u003e\u003cstrong\u003eWhy this breaker stands out\u003c\/strong\u003e\u003c\/p\u003e \u003cul\u003e \u003cli\u003e\n\u003cstrong\u003ePlug-On design\u003c\/strong\u003e delivers fast, secure installation with minimal tools and no complex wiring fuss, reducing commissioning time and potential for loose connections.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eGenuine Square D performance\u003c\/strong\u003e—part number Q1L390 ensures exact fit and factory-tested operation within compatible panel systems and distribution setups.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThree-pole protection\u003c\/strong\u003e for balanced, synchronized shutdown across all phases in 3-phase systems, enhancing safety and reliability in commercial and industrial environments.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003e90 A capacity\u003c\/strong\u003e provides robust overcurrent protection for circuits that demand higher current handling while maintaining dependable protection standards.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eOEM BOM alignment\u003c\/strong\u003e makes it ideal for replacement scenarios where preserving the original equipment configuration matters for documentation and future servicing.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eStock-ready spare\u003c\/strong\u003e to minimize downtime during maintenance windows or unexpected outages, keeping critical equipment up and running.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eIdeal use cases\u003c\/h2\u003e \u003cp\u003eThe Q1L390 is best suited for:\u003c\/p\u003e \u003cul\u003e \u003cli\u003eReplacement projects in panelboards and electrical distribution setups where the original part number must be preserved.\u003c\/li\u003e \u003cli\u003eSpare inventory for maintenance fleets serving commercial facilities, manufacturing floors, and data centers where quick fault isolation is essential.\u003c\/li\u003e \u003cli\u003eThree-phase installations that require synchronized tripping across all poles to safeguard equipment and personnel.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eCompatibility and support\u003c\/h2\u003e \u003cp\u003eIf you’re unsure about fit, AmpState offers guidance to confirm compatibility with your panel model. \u003cstrong\u003eNeed help matching a part number or confirming fit? Message us and we’ll help you verify the correct breaker for your application.\u003c\/strong\u003e\u003c\/p\u003e \u003ch2\u003eInstallation and practical tips\u003c\/h2\u003e \u003col\u003e \u003cli\u003ePower down and lock out the system before beginning any work.\u003c\/li\u003e \u003cli\u003eIdentify the correct slot in the panelboard for a 3-pole breaker.\u003c\/li\u003e \u003cli\u003eAlign the Q1L390 with the bus stabs and firmly snap it into place until it seats securely.\u003c\/li\u003e \u003cli\u003eReconnect conductors per the panel’s wiring diagram, then restore power and test the circuit to verify proper operation.\u003c\/li\u003e\n\u003c\/ol\u003e \u003cp\u003eBuilt for dependable performance in everyday electrical distribution tasks, the Square D Q1L390 90A 3P Circuit Breaker—Plug-On from AmpState—helps you maintain safety, reliability, and efficiency across your electrical infrastructure.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"AmpState","offers":[{"title":"Default Title","offer_id":46413668974754,"sku":"Q1L390","price":810.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/8094\/6850\/files\/master_generic_83963f7f-600e-419f-90c6-e7677089642b.png?v=1765492973","url":"https:\/\/www.ampstate.com\/products\/square-d-q1l390-90a-3p-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}