Wiring Question on M1165

[Mainsail]

I am sure they are talking about the negative terminal, it goes to the negative shunt mounted on the inside of the battery box, they WARN that if the negative lead fails, has a poor connection or has inadequate wire size you will over-volt the 12V side so the ground is THE most important connection.
You need big wire (10ga MIN) and the correct terminals installed with the correct tools ( I always solder them after using a hydraulic crimper on them then I seal them with gelled heat shrink.
Do it right the first time.....

That's what I'm talking about, there is nothing labeled Neg - only input, output, and 0V.

I see a bolt on the left side of the shunt that is already pretty crowded, I think that's probably the best ground.

Made my own mondo ring terminal- notched this washer and soldered the 10ga wire in. Seems to be holding as I couldn't yank or wiggle it out.

 

[thoner7]

I decided to order a similar fuse block to the one in that video I linked to.

As far as the negative goes, I plan to connect the Orion unit’s ground to the ground bar in the battery box, and then connect the fuse block’s ground to the ground terminal on the Orion unit. That will obviously connect back to the grounding block but through the Orion.

Is there something I am unaware of as to why I should NOT do this?!

 

[thoner7]

Is 70A the input or output?

The fuse should be about 1.2 times the max current draw of the device, and the wire should be sized for the fuse. So assuming 70A is the input current, you're looking at around a 90A fuse and 4AWG wire minimum.

Posting this for future readers doing this project: https://diysolarforum.com/threads/help-with-victron-orion-24-12-converter-please.47648/

Recommends 8 gauge wire and 50 amp fuse on line feeding the Orion unit