Blue Sea Terminal Fuse, 300 Amp, Gray
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You have 30 days to request a return. All sale items are final sale.
Blue Sea MRBF Terminal Fuse 300A (Gray) provides space-saving, ignition-protected DC main circuit protection with a clear window for quick visual inspection of a blown condition.
Key Features
- 300 amp MRBF terminal fuse for DC main circuit protection on large battery banks
- Interrupt rating satisfies ABYC requirements for DC main circuit protection
- Ignition protected for safe installation aboard gasoline powered boats
- Clear window for visual indication of blown condition
- Color coded for each amperage
- Requires a terminal fuse block—does not mount directly to the battery terminal
Intended Use
- Inverter battery feed protection
- Windlass circuit protection
- Bow thruster circuit protection
- DC main circuit protection for large battery banks
Product Details
- Product: Blue Sea Terminal Fuse, 300 Amp, Gray
- SKU: 661-5190
- Fuse type: MRBF terminal fuse (terminal mount fuse)
- Color: Gray
- Amperage: 300 Amp
- Visual indication: Clear window for blown-fuse condition
- Installation note: Requires a terminal fuse block (do not mount directly to the battery terminal).
Parts Desk Insights
Best Use Case: Use as the primary fuse for DC systems where ABYC DC main circuit protection guidance applies—especially on large battery banks feeding inverters, windlasses, or bow thrusters.
Common Issues: Most installation problems come from skipping the required terminal fuse block (the fuse must be mounted using the correct fuse block). If a fuse repeatedly opens, inspect load inrush/operation (inductive loads like motors may draw higher inrush) and verify wire sizing and connections before replacing the fuse.
Related Products & Accessories
- Terminal Fuse Block (for 30 to 300A MRBF fuses) - Pair this fuse with the appropriate MRBF terminal fuse block required for installation.
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.