From the maker
What the catalog says
Manufacturer, model, ratings and which terminal does what come from the catalog. A newer revision, or the nameplate on the unit in your hand, can say something different — when it does, the nameplate wins.
Blue Sea Systems
Blue Sea 5025 ST Blade Fuse Block
6-circuit ATC/ATO blade fuse block with integrated negative bus and clear cover. 100 A max per block, 30 A per circuit, 32 V DC max. Accepts ATO/ATC fuses 1–30 A.
This part has no feed of its own to size, so its cables are sized from the complete system topology once you draw what it connects to.
Wiring diagram
How the BS 5025 is wired.
The drawing shows where the feed, the return and the fuse land on this part. The starter uses the same reference circuit and sizing assumptions. Read the installation notes for manufacturer requirements before adapting the runs.
Build it out
Build the system it goes in.
Open the canvas with 5025 already placed, then add your batteries, charging, distribution and loads around it.
Every cable you draw there is sized against ABYC E-11, from the same tables as the reference on this page.
Technical reference
Specs, terminals and the parts around them.
The catalog facts for this part, which terminal takes what, and the hardware you'll want around it. Check the nameplate on your own unit before you order.
Catalog specification
This part has no rating of its own to list. What matters is its terminals — see the map beside.
Supporting parts
- A lug or terminal to match each post on the part
- Strain relief and boots so nothing chafes or shorts
- Cable and fuses sized once the whole system is drawn
Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.
Terminal map
Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.
IN +
in-pos
positive · input
IN −
in-neg
negative · bidi
1
c1
positive · output
2
c2
positive · output
3
c3
positive · output
4
c4
positive · output
5
c5
positive · output
6
c6
positive · output
1
n1
negative · bidi
2
n2
negative · bidi
3
n3
negative · bidi
4
n4
negative · bidi
5
n5
negative · bidi
6
n6
negative · bidi
Method & provenance
What is known, assumed and computed.
The manufacturer publishes some of these numbers and Crimp works out the rest. It's worth knowing which is which.
ABYC E-11
What Crimp worked out
Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The run length and the current above are what drive the result. Crimp doesn't know how warm your space gets; draw the cable inside an engine-bay zone on the canvas and it sizes for the heat.
Next step
Draw the BS 5025 into your own system.
It lands on the canvas already placed. Add what it connects to, and every run gets its wire and fuse as you draw.