Blue Sea Systems 7138 187 Series 40A Surface Mount DC Circuit Breaker

The Blue Sea Systems 7138 is a 40-amp thermal circuit breaker from the 187 Series, designed for surface mounting in marine DC electrical systems up to 48 volts. This rugged device combines switching and circuit protection in a single unit, eliminating the need for separate components while providing reliable overcurrent protection.

Key Features:

• Trip-free design prevents override during fault conditions—cannot be held "ON" when overcurrent is detected
• Waterproof construction suitable for harsh marine environments
• Ignition protected per SAE J1171 standards—safe for gasoline-powered vessels
• Large single-lever operation with clear ON/OFF/TRIP indication in vertical or horizontal orientation
• Robust 5/16" terminal studs provide high-torque connections for heavy gauge wire lugs
• Recessed mounting holes create a clean, professional appearance
• Thermoset polyester case provides durability and chemical resistance

Technical Specifications:

• Circuit Breaker Class: Type III - Switchable/Manual Reset, Trip Free
• Type: Thermally responsive bi-metal blade
• Voltage Rating: 48 Volts DC Maximum
• Current Rating: 40 Amperes
• Interrupt Rating: 5,000A @ 12V DC, 3,000A @ 24V DC, 1,500A @ 42V DC
• Operating Temperature Range: -25°C to +82°C (-13°F to +180°F)
• Case Material: Thermoset polyester

Ideal for protecting high-current DC circuits in marine applications including windlasses, thrusters, inverters, and other heavy electrical loads. The surface mount design allows for easy installation in electrical panels or bulkhead mounting.