{"product_id":"blue-sea-120a-187-series-surface-mount-thermal-circuit-breaker","title":"Blue Sea 120A 187-Series Surface Mount Thermal Circuit Breaker","description":"\u003ch2\u003eIntegrated 120A Overcurrent Protection and Manual Battery Switching\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003eBlue Sea 187-Series 120A Surface Mount Thermal Circuit Breaker\u003c\/strong\u003e delivers dependable electrical protection and manual switching in a single, consolidated unit. Designed for demanding marine, 4WD, caravan, and off-grid power architectures, this heavy-duty breaker eliminates the need to wire separate fuse holders and battery isolation switches. By combining both functions into one compact surface-mount footprint, it simplifies installation, reduces potential failure points in your wiring loom, and saves valuable bulkhead or panel space.\u003c\/p\u003e\u003cp\u003eUnlike standard inline fuses that require spare components when a fault occurs, this resettable thermal circuit breaker features a prominent, high-visibility yellow reset lever. The lever provides an immediate visual indication of the trip status and allows for straightforward manual resets or deliberate circuit isolation during routine system maintenance. Furthermore, the housing is designed so the lever can be oriented for either vertical or horizontal mounting layouts, offering clear readability regardless of your installation constraints.\u003c\/p\u003e\u003ch3\u003eKey Features and Technical Benefits\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDual-Function Design:\u003c\/strong\u003e Combines 120A thermal overcurrent protection and manual ON\/OFF circuit switching in one robust device.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrip-Free Operation:\u003c\/strong\u003e Internal safety mechanism ensures the breaker cannot be manually held in the ON position while a dangerous fault current persists.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIgnition Protected:\u003c\/strong\u003e Engineered within a sealed, weatherproof housing that is safe for installation aboard petrol-powered marine vessels and near vented battery compartments.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeavy-Duty Terminal Studs:\u003c\/strong\u003e Equipped with robust 5\/16\" (Approx. M8) stainless steel terminal studs that provide ample clearance for heavy-gauge cable lugs and support high-torque connections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-Visibility Lever:\u003c\/strong\u003e Large yellow actuator clearly displays whether the circuit is active, tripped, or manually isolated, and suits both vertical and horizontal orientations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSurface Mount Form Factor:\u003c\/strong\u003e Pre-drilled mounting holes allow for straightforward, secure attachment directly to flat panels, battery boxes, or bulkheads.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eEngineered for Safety and High-Torque Reliability\u003c\/h3\u003e\u003cp\u003eWhen working with high-amperage DC systems, poor electrical connections and substandard protection hardware can lead to severe voltage drop, melted housings, and thermal hazards. The Blue Sea 187-Series mitigates these risks through precision engineering. Its \u003cstrong\u003etrip-free mechanism\u003c\/strong\u003e is a critical safety asset; if a short circuit or overload occurs down the line, the internal thermal element will trip and physically prevent the user from forcing the circuit closed until the fault is resolved and the unit has cooled.\u003c\/p\u003e\u003cp\u003eIn harsh marine and mobile environments, moisture ingress and vibration often degrade standard electrical connections. This breaker features a weatherproof housing that shields internal components from dust and water spray. The 5\/16\" (Approx. M8) stainless steel studs resist corrosion and allow installers to apply proper torque specifications without stripping threads, ensuring a low-resistance connection that handles continuous heavy loads cleanly.\u003c\/p\u003e\u003ch3\u003eApplication Guidelines and Exclusions\u003c\/h3\u003e\u003cp\u003eThis 120A thermal breaker is well suited for protecting main DC feed wires, high-output alternator charge lines, auxiliary battery banks, and windlass or bow thruster circuits. Its ignition-protected rating makes it particularly valuable for boat builders and marine electricians working around inboard petrol engine bays.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eImportant Application Note:\u003c\/strong\u003e Do not use this circuit breaker as a frequent manual switch in applications where high inrush currents are expected, such as directly switching large power inverters without pre-charge circuitry, as repeated high-inrush switching can prematurely wear the internal contacts.\u003c\/p\u003e\u003ch3\u003eUpgrade Your Electrical Protection\u003c\/h3\u003e\u003cp\u003eEquip your marine vessel, caravan, or off-grid power system with professional-grade overcurrent protection. Add the Blue Sea 187-Series 120A Surface Mount Thermal Circuit Breaker to your setup today for safe, resettable circuit management.\u003c\/p\u003e","brand":"Blue Sea","offers":[{"title":"Default Title","offer_id":43631590080573,"sku":"BS-7146B","price":167.82,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0602\/3918\/3933\/files\/blue-sea-120a-surface-mount-circuit-breaker-bs-7146b.png?v=1792904256","url":"https:\/\/www.solar4rvs.com.au\/products\/blue-sea-120a-187-series-surface-mount-thermal-circuit-breaker","provider":"Solar 4 RVs","version":"1.0","type":"link"}