Blue Sea Systems ST Glass 6 Circuit Fuse Block, 32V DC, 100A, AGC/MDL Fuses
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Overview
The Blue Sea Systems ST Glass 6 Circuit Fuse Block is a compact DC fuse block for organizing up to six protected branch circuits on a boat. It is rated for 32V DC systems, with a maximum of 100A per block and 30A per circuit, making it a practical fit for many low-voltage marine loads such as electronics, cabin accessories, pumps, lighting circuits, and other fused DC equipment.
This ST Glass fuse block accepts AGC fast-acting, MDL time-delay, and other 3AG glass fuses. The clear polycarbonate cover protects the conductive parts, helps meet ABYC and USCG insulation requirements, and includes space for circuit labeling and spare fuse storage, which makes inspection and service easier in a helm, console, cabin locker, or other protected electrical area.
Key features
- Six fused circuits for consolidating DC branch protection in one organized location.
- Rated for 32V DC, with 100A maximum per block and 30A maximum per circuit.
- Accepts AGC, MDL, and other 3AG glass fuses for common marine DC circuit protection.
- Tin-plated copper buses and phosphor bronze fuse clips support the full 30A circuit rating.
- Clear polycarbonate cover insulates conductive parts and stores spare fuses inside the block area.
- Label recesses on the cover help keep circuits identified for troubleshooting and future service.
- Reinforced polycarbonate base and #8-32 screw terminals with captive star lockwashers support secure wiring connections.
- Mounts with #10 screws for installation on a flat electrical panel, bulkhead, or equipment board.
Variants
This product is offered in two configurations, both based on the same ST Glass 6 circuit format with a protective cover.
The main difference is the negative bus. Both versions support the same 32V DC system rating, 100A block rating, 30A per circuit rating, AGC and MDL fuse compatibility, and #8-32 screw terminal style.
- 5015: Bus Type Negative Bus and Cover. This version combines the six fused positive circuits with an integrated negative bus, giving accessory negative returns a common landing point near the fuse block.
- 5018: Bus Type Cover. This version provides the six fused circuits with the protective cover, without an integrated negative bus, for installations where negative returns are handled on a separate bus bar.
Installation and setup
Install the block in a dry, accessible location where the cover can be removed and each fuse can be inspected without disturbing nearby wiring. Common locations include a helm electrical panel, electronics locker, cabin distribution area, or a protected equipment board near the loads being served.
Use wire size and fuse values that match the connected equipment and the circuit length. The fuse protects the wire, so each circuit should be sized for the load, conductor gauge, and installation conditions. The #8-32 screw terminals with captive star lockwashers help maintain firm connections in a marine environment where vibration is a normal part of service.
Compatibility and fit
This fuse block is for DC circuits up to 32V and is compatible with AGC, MDL, and other 3AG glass fuses. It works well where a boat already uses glass fuses or where the installer wants an organized block with labeling and spare fuse storage under the cover.
The version with a negative bus is better suited to compact wiring layouts where accessory negative wires need to return close to the protected circuits. The version without a negative bus fits systems that already use a separate negative bus bar or a larger DC distribution layout.
Shipping
We ship worldwide from the United States. Rates are calculated at checkout based on destination and package weight. Some items include free shipping, which will show automatically. Not every product is eligible for international shipping; checkout will confirm eligibility. We do not ship to PO Boxes except through USPS, and not all packages qualify.
Processing and dispatch
Most orders are verified, packed, and handed to the carrier within 1 to 2 business days. Some products may need extra handling time or ship directly from the manufacturer. For certain international orders, inventory transfers between warehouses may add time. If any delay is expected, we will let you know the dispatch date.
Delivery and tracking
Deliveries are handled by trusted carriers such as USPS, UPS, FedEx, and DHL. Estimated arrival times appear at checkout and depend on your location and the service you choose. These are estimates and can be affected by customs or carrier disruptions. A shipping confirmation with a tracking link is emailed when your order ships, and tracking may take up to 24 hours to update. You can also view tracking in your account.
Duties, taxes, and support
International customers are responsible for any customs duties, taxes, and fees charged by the destination country. If these charges are refused and a shipment returns to us, the carrier’s return cost and any re-entry customs fees will be deducted from the refund. If your order is late or you need help, contact cs@qualityboatparts.com and we will assist you.
Quality Boat Parts is a reseller. Many items include a manufacturer’s warranty, and all warranty service is handled directly by the manufacturer. We do not manage or administer warranty claims on behalf of customers.
Warranty terms, coverage, and duration are set by each manufacturer. Issues involving defects, repairs, or replacements must be addressed with the manufacturer’s support team. When available, the warranty period is listed on the product page. If it is not shown, contact us or the manufacturer for details before purchasing.
To start a claim, the customer must contact the manufacturer and follow their process. Keep your proof of purchase and original packaging, and register the product if the manufacturer requires it, as these are often needed for warranty service.
We are happy to help you find the right contact or documentation, but we cannot decide outcomes or intervene in claim resolutions. For guidance, email cs@qualityboatparts.com.