Blue Sea Systems 7139 187 Series DC Circuit Breaker - Surface Mount, 50 Amps
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Blue Sea Systems 7139 187 Series DC Circuit Breaker is a surface-mount breaker built for medium-duty DC circuit protection where both switching and circuit protection are required. It features a clearly visible single-lever operation, weather resistance, and ignition protection for safer installation aboard gas-powered boats.
Key Features
- Single lever operation is clearly visible.
- Ignition protected (conforming to SAE J1171), designed for installation aboard gas-powered boats.
- Weather resistant for harsh marine environments.
- Surface mount design for accessible, straightforward installation.
- 5/16-18 terminal studs.
- Maximum voltage: 42 volts DC.
Intended Use
- Marine DC electrical systems (switching + circuit protection)
- Boat accessory circuits and onboard DC loads
- DC distribution where surface-mount thermal breaker-style protection is needed
- Off-grid, RV, and similar 42V DC systems requiring ignition-protected operation (when installed in accordance with local requirements)
Product Details
- Blue Sea Systems 7139 187 Series DC Circuit Breaker - Surface Mount, 50 Amps
- Type/series: 187 Series DC circuit breaker (surface mount).
- Current rating: 50 Amps.
- Maximum voltage: 42 volts DC.
- Ignition protection: SAE J1171 (ignition protected).
- Mounting: Surface mount.
- Terminal studs: 5/16-18 terminal studs.
- Operation: Single lever operation (visually apparent).
- Environmental feature: Weather resistant.
Parts Desk Insights
Best Use Case: Use for DC circuits on marine vessels where you need both a convenient disconnect/switching function and circuit protection in one device, with ignition protection and weather resistance.
Common Issues: If the breaker trips repeatedly, confirm the load isn’t exceeding the breaker’s DC rating and check for wiring issues (loose terminations, undersized cable, or shorts). Also verify terminal hardware and mating surfaces so the 5/16-18 studs clamp properly and consistently.
Related Products & Accessories
- Circuit Breakers - Browse the circuit breaker category to find matching amps and other protection devices for your DC panel.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.