{"product_id":"siemens-jd63b400-300a-400v-3-pole-bolt-on-circuit-breaker","title":"Siemens JD63B400 - 300 A, 400 V, 3-Pole Bolt-On Circuit Breaker | AmpState","description":"\u003cdiv\u003e\n\u003cp\u003eSiemens JD63B400 is a rugged 300A, 400V, 3-pole bolt-on molded case circuit breaker designed to protect your branch circuits with precision in panelboards and loadcenters. Built for dependable overcurrent and short-circuit protection, this breaker keeps critical systems safe in residential, commercial, and light industrial settings.\u003c\/p\u003e \u003ch2\u003eWhy this bolt-on Siemens breaker stands out\u003c\/h2\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eSecure bolt-on mounting\u003c\/strong\u003e delivers a rigid, vibration-resistant bus connection, maintaining consistent electrical contact even in environments with machinery or movement.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThermal-magnetic trip unit\u003c\/strong\u003e provides stable, repeatable protection across a range of temperatures and loading conditions, combining long-term reliability with fast fault response.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003e3-pole design\u003c\/strong\u003e ensures simultaneous disconnection of all three phases, enhancing safety and protection for balanced 3-phase loads.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eOEM compatibility\u003c\/strong\u003e compatible with matching Siemens OEM loadcenters and panelboards, simplifying replacement and upgrade projects.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eIdeal use cases\u003c\/h2\u003e\n\u003cp\u003eDesigned for main feeder protection and branch circuit safety, the JD63B400 excels in:\u003c\/p\u003e\n\u003cul\u003e \u003cli\u003eNew panelboard installations where a robust 3-pole, bolt-on breaker is required\u003c\/li\u003e \u003cli\u003eRetrofits and service upgrades in residential, commercial, and light industrial environments\u003c\/li\u003e \u003cli\u003eControl and distribution panels needing reliable overcurrent and short-circuit protection\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003eWhat it protects and how it benefits you\u003c\/h2\u003e\n\u003cp\u003eThe JD63B400 safeguards your electrical system by detecting overloads and short circuits across all three phases, then tripping predictably to prevent damage, nuisance outages, and dangerous hot spots. A thermal element handles gradual overloads, while the magnetic element responds to high fault currents for rapid isolation of the circuit. With this combination, you get dependable protection that remains consistent despite varying loads and ambient temperatures.\u003c\/p\u003e \u003ch3\u003eKey specifications\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eManufacturer:\u003c\/strong\u003e Siemens\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003ePart number:\u003c\/strong\u003e JD63B400\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eAmperage rating:\u003c\/strong\u003e 300 A\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVoltage rating:\u003c\/strong\u003e 400 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 Bolt-on\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Thermal-magnetic molded case circuit breaker\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eApplications:\u003c\/strong\u003e Branch circuit overcurrent and short-circuit protection\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch2\u003ePractical tips for installation and operation\u003c\/h2\u003e\n\u003cul\u003e \u003cli\u003eEnsure your panelboard or loadcenter supports bolt-on breakers to maximize compatibility and performance.\u003c\/li\u003e \u003cli\u003eVerify alignment and clean connections during bolt-on mounting to maintain the vibration resistance and secure bus contact.\u003c\/li\u003e \u003cli\u003eUse in applications where stable, predictable trip characteristics are important, such as systems with variable loads or in environments with temperature fluctuations.\u003c\/li\u003e \u003cli\u003eKeep spare JD63B400 units on hand for quick replacements in service upgrades or panel refurbishments.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003eWhether upgrading an existing panel or installing a new, reliable protection solution, the Siemens JD63B400 3-pole bolt-on molded case circuit breaker delivers robust, dependable performance for residential, commercial, and light industrial electrical designs.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Amp State","offers":[{"title":"Default Title","offer_id":46349814530210,"sku":null,"price":710.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/8094\/6850\/files\/siemens_breaker_and_panel_ad7370ec-4167-4dcf-a440-a41875966b7e.png?v=1764157612","url":"https:\/\/www.ampstate.com\/products\/siemens-jd63b400-300a-400v-3-pole-bolt-on-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}