{"product_id":"siemens-km3b400-circuit-breaker","title":"Siemens | KM3B400 | Circuit Breaker | 400A | 3-Pole | 600V | 50kA | Bolt-On","description":"\u003cdiv\u003e\n\u003cp\u003eMeet the Siemens KM3B400 Circuit Breaker — a rugged 3-pole, 400A protection device built for bolt-on installation in compatible panels. Engineered for reliability in demanding environments, it handles up to 600V with a formidable 50kA interrupting rating, delivering decisive fault current protection that helps keep equipment and production lines up and running.\u003c\/p\u003e \u003ch3\u003eKey specifications at a glance\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eAmperage:\u003c\/strong\u003e 400 A\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003ePoles:\u003c\/strong\u003e 3-Pole\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVoltage rating:\u003c\/strong\u003e 600 V\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eInterrupting capacity:\u003c\/strong\u003e 50 kA\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eMounting:\u003c\/strong\u003e Bolt-On\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003ePart reference:\u003c\/strong\u003e KM3B400 (best compatibility reference)\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eWhy choose the KM3B400 bolt-on breaker\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eSecure, vibration-resistant mounting:\u003c\/strong\u003e The bolt-on design provides solid mechanical retention in environments with equipment movement or vibration, reducing the risk of loose connections over time.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eThree-phase protection with synchronized trip:\u003c\/strong\u003e A true 3-pole configuration ensures all phases trip together, safeguarding motors and three-phase loads from imbalance or single-phase faults.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eHigh fault-current resilience:\u003c\/strong\u003e With a 50kA interrupting rating, this breaker is ready to interrupt substantial fault currents, helping minimize equipment damage and downtime.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eIndustrial-grade voltage handling:\u003c\/strong\u003e Rated for up to 600V, it fits a wide range of commercial and light industrial distribution systems and motor feeders.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eClear compatibility guidance:\u003c\/strong\u003e The KM3B400 part number is the most reliable reference for matching panels and bus configurations — always verify fit and ratings before ordering.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003eIdeal applications and use cases\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003eRetrofits and replacements in Siemens-compatible panels where a 400 A, 3-pole, 600 V bolt-on breaker is required.\u003c\/li\u003e \u003cli\u003eMotor feeders and main disconnect sections in industrial facilities, manufacturing lines, and commercial buildings with three-phase loads.\u003c\/li\u003e \u003cli\u003eMaintenance upgrades that demand solid mechanical retention and reliable fault protection in panels exposed to vibration or continuous cycling.\u003c\/li\u003e\n\u003c\/ul\u003e \u003ch3\u003ePractical guidance for installation and safety\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003eAlways confirm fit and ratings against your panel model before ordering; the KM3B400 reference is your best compatibility indicator.\u003c\/li\u003e \u003cli\u003ePower down the panel and follow lockout\/tagout procedures before mounting or replacing the breaker.\u003c\/li\u003e \u003cli\u003eEnsure the mounting surface and bus connections align with the bolt pattern and torque specifications recommended for bolt-on installations.\u003c\/li\u003e \u003cli\u003eInspect conductors and terminations for clean contact surfaces to maintain optimal electrical performance and reliability.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003eThe Siemens KM3B400 is more than a protective device—it’s a strategic investment in uptime, safety, and controllable power for demanding electrical systems. If your panel or project requires a 400A, 3-pole, bolt-on breaker with a 600V rating and 50kA interrupting capacity, this KM3B400 unit is designed to meet those exacting specifications with precision.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Siemens","offers":[{"title":"Default Title","offer_id":46424395940002,"sku":"KM3B400","price":310.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/8094\/6850\/files\/siemens-km3b400-circuit-breaker-400a-3-pole-600v-50ka-bolt-834.webp?v=1789351503","url":"https:\/\/www.ampstate.com\/products\/siemens-km3b400-circuit-breaker","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}