Backbone Power via ACU-400

[rsqunit]

I just finished my installation (see diagram attached) and per documentation recommendation and advice on this forum, I powered the backbone from the ACU-400.

After a bit of testing the backbone lost power and I figured out the SeaTalkng power fuse on the ACU-400 was blown.

Turns out this is a 3A fuse, but all the SeaTalk docs talk about 5A fuses.

Is the ACU-400 not sufficient for this purpose? As you can see the backbone is balanced and I followed all other recommendations.

Maybe it was just a fluke, but I figured I should ask to make sure before I take the boat out!