Blue Sea 7143 187 - Series Thermal Circuit Breaker - 90Amp

The Blue Sea 7143 187-Series Thermal Circuit Breaker—90Amp is the reliable electrical backbone marine electricians and boat owners trust to protect high-draw systems on the water. This surface-mount device combines switching and overload protection into a single, compact unit, eliminating the need for separate breakers and switches in tight engine compartments or electrical panels. Whether you're running a powerful trolling motor, auxiliary charging system, or heavy-duty thruster, this 90-amp breaker delivers the safety margin serious boaters demand when lives and equipment depend on stable electrical performance.

Built to SAE J1171 marine electrical standards, the Blue Sea 7143 uses thermal-trip technology to automatically disconnect power when current exceeds safe operating limits—protecting wiring, batteries, and electronics from fire risk and catastrophic failure. The 90-amp rating is calibrated for vessels with substantial power demands, and the integrated switch function lets operators manually isolate circuits without hunting for a separate panel switch. Its compact 5 × 3 × 7-inch footprint and lightweight 0.6-pound design make installation straightforward in battery banks, engine rooms, and distribution panels, while the surface-mount configuration suits both new builds and retrofit upgrades.

Experienced boaters and marine electricians select the Blue Sea 7143 when reliability cannot be compromised—particularly on commercial vessels, charter boats, and offshore cruisers where electrical faults can strand crews far from help. The thermal-trip mechanism responds faster than traditional fuses and resets without replacement, reducing downtime and cost over the life of the vessel. Installation requires only 12V or 24V DC-rated wiring and standard marine-grade terminals; consult your vessel's wiring diagram to verify compatibility with your specific amperage and voltage configuration before mounting.