Blue Sea 7038 40A 187-Series Panel Mount Breaker

The Blue Sea Systems 7038 is a 40 amp panel mount breaker in the 187 Series, the smallest of the panel mount group, rated to 48 volts DC.

Forty amps sits between branch protection and main protection, covering circuits too heavy for a panel breaker but well short of a main feed. An electronics sub-panel, a small windlass or a refrigeration compressor all land in that gap, and a 15A branch breaker will not hold them.

A thermally responsive bi-metal blade does the work, which tolerates the brief surge a motor draws on starting rather than tripping on it. That matters most at the smaller ratings, where a startup surge is a larger multiple of the running current.

Interrupt capacity is 5,000 amperes at 12 volts DC, 3,000 at 24 and 1,500 at 42, and it is Type III class, switchable with manual reset and trip free. The round self-trimming case installs with a standard hole saw and needs no separate mounting panel or bezel. Waterproof and ignition protected to SAE J1171. Explore more marine circuit breakers.

• 40A, the smallest panel mount in the series
• For circuits between branch and main protection
• Bi-metal tolerates motor starting surge
• That inrush is a bigger multiple at small ratings