Blue Sea Systems ST blade fuse block 4 Circuit + Neg - Terminal Mount, With cover, 30A per circuit, 100A total

The Blue Sea Systems ST Blade Fuse Block is a battery-stud mounted, ignition-protected fuse distribution kit that gives you six fused circuits plus a negative bus for compact, secure power distribution.

Designed for marine and small-vehicle electrical layouts, this Blue Sea Systems fuse block installs directly on the battery terminal stud to minimize wiring runs and clutter. It combines a positive fused block that accepts blade (ATO/ATC) fuses with an integrated negative bus and comes with nylon-insulated ring terminals and an insulating cover. Rated for a total block capacity of 100 A and up to 30 A per circuit, the unit is built to meet common ignition-protection and insulation standards for gasoline-engine compartments.

How does mounting on the battery stud help my installation?

Mounting on the battery stud reduces the length of high-current wiring and centralizes the source connection, which simplifies routing and improves reliability. It also frees panel space and lowers the chance of loose, exposed connections in tight engine or bilge areas.

• Direct battery-stud connection for shorter mains
• Less bulk on bulkhead or panel mounts
• Clear, centralized power distribution point
• Reduces potential voltage drop from long runs

What fuse types and current limits does this block accept?

The block accepts standard ATO/ATC blade fuses, allowing you to protect individual circuits with widely available fuse sizes. Each circuit is rated up to 30 A, while the entire block supports up to 100 A total, letting you combine multiple protected loads safely when sized correctly.

• ATO/ATC blade fuses fit each circuit
• Up to 30 A per fused circuit
• 100 A total block capacity for main distribution
• Suitable for common accessory and lighting loads

Is the kit ready for a safe, engine-compartment installation?

Yes — the fuse block kit includes an insulating cover and meets ignition-protection requirements, making it appropriate for installations in gasoline engine spaces. Nylon-insulated ring terminals and screw terminals help create secure wire terminations that conform to recreational marine wiring practices.

• Ignition-protected design for gasoline engine compartments
• Insulating cover compliant with ABYC/USCG style insulation needs
• Nylon-insulated ring terminals included for reliable terminations
• Screw terminals for straightforward wire clamping

How does the negative bus simplify grounding and returns?

The integrated negative bus centralizes all return connections at the fuse block location, so you can run individual negative leads to the same point rather than back to the battery. This approach streamlines wiring and makes troubleshooting and additions easier.

• Single negative bus for multiple return connections
• Simplifies tracing and diagnosing circuits
• Reduces the number of separate negative runs to the battery
• Provides neat, centralized grounding for accessory circuits

Who is this for? Boat owners, small-vehicle fabricators, and DIY electrical installers who need a compact, ignition-protected fuse distribution solution will benefit from the Blue Sea Systems ST Blade Fuse Block. It’s ideal where space is limited and where a tidy, battery-mounted distribution point reduces wiring complexity — for example, on small boats, personal watercraft, ATVs, or custom battery installs that require reliable blade-fuse protection and a dedicated negative bus.