Blue Sea Systems ST-Blade Water-Resistant Fuse Block, 4 Circuit, 80A, 32V DC, IP66, ATO/ATC

Overview

The Blue Sea Systems ST-Blade Water-Resistant Fuse Block is a compact 4-circuit fuse block for protected DC branch circuits on boats, built for ATO and ATC blade fuses as well as ATO/ATC-style low-profile circuit breakers.

It is rated for 32V DC systems, with 80A maximum per block and 25A maximum per circuit. The tin-plated copper C11000 bus and fuse clips help keep electrical connections organized in damp marine spaces where corrosion control and clean wiring matter.

The block uses #8-32 screw terminals with captive star lock washers, accepts one 8 AWG to 4 AWG input wire and four 16 AWG to 10 AWG load wires, and has mounting holes with clearance for 1/4 in. or 6 mm screws. It works well for small DC distribution runs feeding electronics, pumps, lighting, accessories, and other fused loads where a covered, water-resistant installation is needed.

Key features

• Four fused branch circuits in a compact block for organized DC distribution on boats.
• 32V DC maximum rating with 80A total block capacity and 25A maximum per circuit.
• Accepts ATO and ATC fast-acting blade fuses, plus ATO/ATC-style low-profile circuit breakers.
• Water-resistant layout with three wire plugs included to help maintain the rating when fewer than four loads are installed.
• Tin-plated copper C11000 bus and fuse clips for electrical contact surfaces suited to marine wiring environments.
• #8-32 screw terminals with captive star lock washers for ring or spade terminals using standard tools.
• Single-side nesting layout lets wiring enter from one side, which helps reduce clutter in tight helm, console, locker, and service-panel spaces.
• Cover includes spare fuse and fastener storage, with four write-on circuit labels for quick circuit identification.

Variants

This fuse block is offered in two cover configurations. The electrical layout, circuit count, voltage rating, amperage rating, terminal type, bus material, and accepted fuse and breaker styles remain consistent across the variants.

The main difference is the cover style. Both versions keep the circuits covered, while the manual-cover version adds wing screws for tool-free cover access and is listed as meeting ABYC/USCG insulation requirements.

• 5056: Cover type standard. This version uses the standard cover configuration for installations where cover removal with normal service access is acceptable.
• 5056100: Cover type manual cover. This version uses a manual cover with wing screws, so the cover can be secured and removed without tools during inspection or fuse service.

Installation and setup

Mount the fuse block where the cover can be opened and the circuit labels can be read during service. The compact footprint and one-side wire entry are useful behind dashboards, inside consoles, under protected lockers, or near small accessory distribution points where wiring space is limited.

Use properly sized marine wire, crimped terminals, and circuit protection matched to each load. The block accepts one main input conductor from 8 AWG to 4 AWG and four load conductors from 16 AWG to 10 AWG, so it is best suited to grouped low-voltage branch circuits rather than large main distribution loads.

Compatibility and fit

This fuse block is for DC systems up to 32V and is suitable for both 12V and 24V boat electrical systems when the connected loads, wiring, and fuses are sized correctly. It accepts common ATO and ATC blade fuses, which makes replacement straightforward during routine maintenance or troubleshooting.

Fuses and circuit breakers are sold separately, so each circuit can be matched to the actual load on the boat. The included write-on labels help keep bilge pumps, electronics, lighting, washdown pumps, and accessory feeds easy to identify later.

Use cases on board

This fuse block is a good match for boat owners and installers adding a small group of protected circuits in an area exposed to spray, humidity, or routine washdown. It is especially useful where a standard uncovered fuse holder would leave wiring less organized or harder to service.

For refits, electronics additions, fishing accessories, cabin upgrades, or helm wiring cleanup, it gives each branch circuit a clear location, visible label, and covered fuse position without taking up much panel space.

Orders are processed within 2 business days, which includes verification, packing, and dispatch. Orders of $100 or more qualify for free shipping when eligible. For orders under $100, shipping costs are calculated at checkout based on destination, package weight, and selected service. International shipping is available for eligible products, and certain items may require additional handling, warehouse transfers, or may ship directly from the manufacturer, which can affect processing time.

Deliveries are handled by preferred carriers such as USPS, UPS, FedEx, DHL, and others depending on your location and selected service. Estimated delivery times are displayed at checkout and may vary due to customs processing, carrier delays, weather, postal disruptions, or other circumstances beyond our control. Once your order ships, you'll receive a confirmation email with tracking information. Tracking may take up to 24 hours to update on the carrier's website and is also available through your account when applicable.

We ship throughout the United States and to most international destinations for products eligible for international shipping. International orders may be subject to customs duties, taxes, brokerage charges, or other import fees, which are the customer's responsibility and are not included in the product or shipping price. PO Boxes are accepted only when shipping through USPS, and not all packages qualify for this option. If your order does not arrive within the estimated delivery window, please contact us at info@apollolighting.com or +1 (954) 375-0100 so we can assist with locating your package.

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Returns may be requested within 30 days of receiving your order. Items must be unused, uninstalled, unaltered, and returned in their original packaging with all tags, packing materials, blank warranty cards, manuals, instructions, accessories, and included items. Certain products, including installed or used electronics, electrical components, lighting, consumables, custom or special-order items, cut-to-length products, safety equipment, and merchandise exposed to water or marine conditions, may not be eligible for return.

To request a return, sign in to your account and select the applicable order and items, and submit your request for review. Eligible unfulfilled items may also be submitted for cancellation within 1 hour of placing the order. Returns or cancellations are not considered approved until you receive confirmation from Apollo Lighting. Please do not ship or drop off merchandise before receiving return approval and instructions.

Customers are responsible for arranging and paying for return shipping unless the return is due to an error by Apollo Lighting or the item is verified as defective, damaged, or incorrect. Missing, damaged, defective, or incorrect items must be reported within 2 business days of delivery, and photos or other documentation may be required for review. If the issue is verified, Apollo Lighting may provide or reimburse return shipping and issue a replacement or refund depending on the circumstances. International customers are responsible for return shipping, duties, taxes, customs charges, brokerage fees, and other costs associated with an international return.

After your return is received and inspected, approved refunds are issued to the original payment method and may take 5-7 business days to appear after processing. Original shipping and handling charges are nonrefundable, and the value of any included free items that are not returned may be deducted from the refund. Apollo Lighting does not charge a standard restocking fee on eligible returns. Returns that are incomplete, damaged, installed, used, altered, improperly packaged, or otherwise do not meet the eligibility requirements may be refused. We recommend using a trackable and appropriately insured shipping service for all customer-arranged returns.

For assistance, contact info@apollolighting.com or call +1 (954) 375-0100.

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Many products sold by Apollo Lighting include a manufacturer's warranty covering defects in materials or workmanship. Warranty terms vary by brand, product category, and model, so eligibility, coverage duration, exclusions, and available remedies are determined by the applicable manufacturer. We recommend reviewing the warranty information provided with your product before installation or use, especially for marine electronics, navigation equipment, lighting, electrical systems, pumps, safety equipment, and other specialized marine products.

If you need warranty service, the claim must follow the process established by the manufacturer, authorized service center, or designated warranty provider. You may be asked for proof of purchase, a serial number, product registration, photos, maintenance or installation records, or other documentation. Apollo Lighting does not determine or modify a manufacturer's warranty coverage or final claim decision, but we are happy to help provide purchase information and direct you to the appropriate manufacturer or warranty resource.

Keep your receipt, product documentation, serial number information, and original packaging when practical. Damage caused by normal wear, misuse, improper installation, insufficient maintenance, corrosion, impact, unauthorized modifications, electrical issues, or operation outside the manufacturer's specifications may not be covered. Warranty claims are separate from standard returns, so a product that has been installed, used, or exposed to marine conditions may no longer qualify for return while still remaining eligible for evaluation under the manufacturer's applicable warranty.

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