{"product_id":"siemens-jd63b300-300a-600v-3-pole-bolt-on-circuit-breaker","title":"Siemens JD63B300 - 300 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState","description":"\u003cdiv\u003e\n\u003cp\u003eMeet the Siemens JD63B300, a rugged 3-pole molded case circuit breaker engineered for dependable overcurrent protection in panelboards and load centers. With a 300 A rating and 600 V capacity, this bolt-on unit is built to handle demanding residential, commercial, and light industrial environments.\u003c\/p\u003e \u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eSecure bolt-on mounting:\u003c\/strong\u003e Provides a rigid, vibration-resistant bus connection that stays put in busy electrical panels.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThermal-magnetic trip unit:\u003c\/strong\u003e Delivers stable, repeatable protection against both overload and short circuits, with fast response when it matters most.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThree-pole design:\u003c\/strong\u003e Provides balanced protection across all phases in three-phase systems.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eMolded case construction:\u003c\/strong\u003e Ensures robust insulation and durability in challenging installations.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eOEM compatibility:\u003c\/strong\u003e Designed to work with matching Siemens OEM load centers and panelboards for a seamless retrofit or upgrade.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVersatile applications:\u003c\/strong\u003e Ideal for branch circuit protection in residential service panels, commercial subpanels, and light industrial equipment.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eTechnical snapshot\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003ePart Number: JD63B300\u003c\/li\u003e \u003cli\u003eType: Thermal-magnetic molded case circuit breaker\u003c\/li\u003e \u003cli\u003eAmperage: 300 A\u003c\/li\u003e \u003cli\u003eVoltage: 600 V\u003c\/li\u003e \u003cli\u003ePoles: 3\u003c\/li\u003e \u003cli\u003eMounting: Bolt-on\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eWhy this breaker stands out\u003c\/h3\u003e\n\u003cp\u003eUnlike lighter, plug-on designs, the bolt-on JD63B300 delivers a stiffer connection that helps prevent bus-bar movement under vibration, which translates to more consistent protection performance over time. The thermal-magnetic trip mechanism combines the best of thermal (overcurrent) and magnetic (short-circuit) protections, offering precise trip thresholds you can rely on in real-world duty cycles.\u003c\/p\u003e \u003ch3\u003eUse cases and installation scenarios\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003eUpgrading a Siemens panelboard to support higher load with a dedicated 300 A feeder circuit.\u003c\/li\u003e \u003cli\u003eReplacing a failed 3-pole breaker in residential, commercial, or light-industrial panel centers that require 600 V and 3-phase protection.\u003c\/li\u003e \u003cli\u003eRetrofits and service upgrades in existing OEM load centers where a bolt-on design ensures secure, vibration-resilient mounting.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003ePractical considerations\u003c\/h3\u003e\n\u003cp\u003eTo ensure optimal performance, verify compatibility with your OEM load center family and confirm the panel’s rating supports a 300 A, 3-pole 600 V breaker. This unit is intended for branch circuit overcurrent and short-circuit protection, providing decisive response to fault conditions while maintaining normal operation in healthy circuits.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Amp State","offers":[{"title":"Default Title","offer_id":46349814464674,"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_3d4d343c-2af9-4b93-b382-18991330d724.png?v=1764157609","url":"https:\/\/www.ampstate.com\/products\/siemens-jd63b300-300a-600v-3-pole-bolt-on-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}