Blue Sea 7042 80A 187-Series Panel Mount Breaker

The Blue Sea Systems 7042 is an 80 amp panel mount breaker in the 187 Series, rated to 48 volts DC.

Eighty amps is the usual size for a small bow thruster or a windlass on a mid-size boat, both of which draw heavily for short periods. That duty cycle is exactly what the thermal bi-metal element handles. It responds to sustained overload rather than to the brief peak of a motor starting under load.

Getting that wrong in the other direction matters too. An oversized breaker on a windlass circuit will let the cable heat well past its rating before it ever notices. The rating follows the conductor, and the windlass itself relies on its own thermal protection.

Interrupt capacity is 5,000 amperes at 12 volts DC, 3,000 at 24 and 1,500 at 42, in Type III class with manual reset and trip free construction. The round self-trimming case installs with a hole saw and needs no bezel. Waterproof, ignition protected to SAE J1171, with 5/16 studs and a lever showing trip status. Explore more marine circuit breakers.

• 80A, sized for a small thruster or windlass
• Bi-metal responds to sustained load, not startup peaks
• An oversized breaker lets the cable overheat first
• The windlass has its own thermal protection