{"product_id":"square-d-cj400na-circuit-breaker","title":"Square D | CJ400NA | Circuit Breaker | 400A | 3-Pole | 600V | Bolt-On","description":"\u003cdiv\u003e\n\u003cp\u003e\u003cstrong\u003eSquare D CJ400NA Circuit Breaker\u003c\/strong\u003e is a robust protective device designed for demanding 600-volt, three‑phase power networks. With a 400-amp rating and bolt-on mounting, this 3‑pole breaker is built for reliability in maintenance, retrofit, and replacement projects where exact specifications matter.\u003c\/p\u003e \u003cul\u003e \u003cli\u003eAmperage: 400A\u003c\/li\u003e \u003cli\u003ePoles: 3-Pole\u003c\/li\u003e \u003cli\u003eVoltage: 600V\u003c\/li\u003e \u003cli\u003eMounting: Bolt-On\u003c\/li\u003e \u003cli\u003ePart Number: CJ400NA\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eWhy the CJ400NA stands out\u003c\/h3\u003e\n\u003cp\u003eDesigned for secure, quick installation, the bolt-on construction provides a solid electrical and mechanical connection that resists vibration in demanding environments. The 3-pole design protects all three phases, delivering balanced protection for motors, feeders, and distribution circuits. A 600V maximum rating makes it suitable for many industrial and commercial installations, while the 400A capacity handles substantial loads without frequent tripping. Since this is a Square D part, it integrates with standard panels and bus configurations from the same family, simplifying replacements and upgrades.\u003c\/p\u003e \u003ch3\u003eUse cases: maintenance, retrofit, and replacement\u003c\/h3\u003e\n\u003cp\u003eThis CJ400NA is ideal when you need a drop-in compatible protective device for aging equipment, panel upgrades, or service upgrades. Common scenarios include upgrading a 3‑phase feeder in a manufacturing line, replacing a failed breaker in a service panel, or retrofitting an older installation to meet newer electrical demands while preserving existing gear. It’s particularly well-suited for environments where reliable protection and fast, secure mounting are critical.\u003c\/p\u003e \u003ch3\u003eFit, compatibility, and best practices\u003c\/h3\u003e\n\u003cp\u003eNotes: Confirm fit and ratings before ordering. The CJ400NA part number is the best reference for compatibility with your panel. To ensure a smooth replacement, verify that your enclosure supports bolt-on breakers of this style, and that the bus and mounting dimensions align with the CJ400NA specification. If in doubt, have your panel model and existing breaker reference handy during ordering.\u003c\/p\u003e \u003ch3\u003ePractical tips for installation and operation\u003c\/h3\u003e\n\u003cp\u003eBefore installation, de-energize the equipment and follow your site safety procedures. Use the correct tools for bolt-on assemblies and torque to manufacturer guidelines. This breaker is designed to slot into compatible Square D panels, preserving coordinated protection across your distribution network. With proper installation, the CJ400NA delivers dependable overcurrent protection for critical loads while enabling straightforward service in the future.\u003c\/p\u003e \u003ch3\u003eWho benefits most\u003c\/h3\u003e\n\u003cp\u003eMaintenance teams, electrical contractors, and facilities engineers responsible for mid-to-large commercial or light-industrial power systems will appreciate the CJ400NA for its combination of robust protection, secure mounting, and clear compatibility references. If you’re upgrading distribution reliability in a 3‑phase 600V environment, this 400A, 3‑pole, bolt-on breaker is designed to pay off through reduced downtime and consistent performance.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Square D","offers":[{"title":"Default Title","offer_id":46426883260578,"sku":"CJ400NA","price":510.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/8094\/6850\/files\/square-d-cj400na-circuit-breaker-400a-3-pole-600v-bolt-210.webp?v=1789636274","url":"https:\/\/www.ampstate.com\/products\/square-d-cj400na-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}