Blue Sea Systems ST Blade Compact Fuse Block, 100A, 32V DC, ATO/ATC

Overview

The Blue Sea Systems ST Blade Compact Fuse Block is a surface-mount fuse block for consolidating ATO and ATC blade-fuse branch circuits in a compact boat electrical panel. It is rated for up to 100A per block and 30A per circuit, with a maximum voltage of 32V DC, making it appropriate for common 12V and 24V DC marine distribution work.

This fuse block is useful when electronics, pumps, lighting, accessories, or other low-voltage DC loads need organized protection without a row of separate in-line fuse holders. The single-side wiring layout lets conductors enter from one side, which helps in tight helm consoles, lockers, cabin panels, and engine-room electrical spaces where clean service access matters.

With the cover secured, the block is ignition protected for gasoline engine compartments under ISO 8846 and SAE J1171. The insulating cover also supports ABYC and USCG insulation requirements, while tin-plated copper buses and fuse clips help maintain good conductivity in damp marine environments.

Key features

• Accepts ATO and ATC fast-acting blade fuses for common marine DC branch circuits.
• Available in 4-circuit and 8-circuit configurations for different panel sizes and accessory counts.
• Rated to 100A per block, 30A per circuit, and 32V DC for 12V and 24V boat systems.
• Single-side wire entry helps reduce the footprint inside small consoles, lockers, and distribution panels.
• Ignition protected when the cover is secure, with ISO 8846 and SAE J1171 compliance for gasoline engine compartment use.
• Insulating cover meets ABYC and USCG insulation requirements for safer exposed-terminal protection.
• Tin-plated copper buses and fuse clips support clean current flow and help resist corrosion.
• Accepts ring terminals or snap fork terminals for flexible wiring during new installations or refits.
• Uses #8 screw mounting, #8-32 screw terminals with captive star lock washers, and a #10-32 terminal stud.
• Fuses are sold separately, allowing each circuit to be fused to the load and wire size used on board.

Variants

This ST Blade Compact Fuse Block is offered in two circuit-count configurations. Both versions use the same compact common-source fuse block concept for ATO and ATC blade fuses.

The main difference between the variants is the number of protected branch circuits. The current ratings, 32V DC maximum voltage, ignition-protected construction with the cover secured, terminal style, and single-side wiring layout remain consistent across the two configurations.

• 5045: 4-circuit configuration. This version keeps four fused branch circuits grouped in a small footprint, which works well for focused accessory panels, compact helm upgrades, or limited DC distribution additions.
• 5046: 8-circuit configuration. This version doubles the number of available fused circuits while keeping the same compact wiring approach, which helps when several electronics, lighting, pump, or accessory circuits need to be organized in one location.

Installation and fit

The block mounts with #8 screws or M4 hardware on a flat surface. The single-side entry layout is helpful when the fuse block is placed along the edge of a panel or bulkhead, since the wiring can be dressed from one direction rather than crossing around the block.

Terminals should be matched to the conductor size and circuit load, using ring or snap fork terminals as appropriate. The terminal stud torque is 24 in-lb, and the screw terminal torque is 18 in-lb, so installation should be tightened carefully without overloading the hardware.

Electrical and system integration

This is a common-source fuse block, so it is used for positive DC branch-circuit distribution rather than for combined positive and negative bus organization. Each branch circuit should use an ATO or ATC fuse sized for the connected load and the installed wire gauge.

For serviceability, the write-on circuit labels help identify each protected circuit at a glance. That matters on boats where quick troubleshooting at the dock or underway can save time, especially around navigation electronics, pumps, lighting, communications gear, and accessory loads.

Use cases on board

The 4-circuit version is a good match for smaller accessory additions or a focused sub-panel, while the 8-circuit version suits a larger group of fused DC loads in one place. Both versions fit well in refits where older in-line fuse holders need to be replaced with a cleaner and easier-to-service layout.

Because the unit is ignition protected when the cover is secured, it can be used in gasoline engine compartment applications where the installation otherwise follows the vessel’s electrical layout and applicable marine wiring practices.

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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