Just an experiment. Small PCB of about 2 euro’s and a regular fuse-holder.
Does any one have thoughts about this solution to power, by example a Cerbo, with a small fuse like this:
Aplication in Lynx distributor:
…but why, as the cerbo GX has an inline slow blow fuse already (3.15A, see here) ?
IMHO your solution is more prone to human error, as you are mixing connections on the busbar.
The un-fused wire between inline-fuse-holder and the battery-pole is not good. Also generally not accepted as a safe way of engineering.
Additionally, opening the fuse-holder leads to a situation were 1 fault can lead to burning the wire when, by example, the open end can reach a grounded metal part.
I never inspected the inline fuse-holder of the cerbo…the ones that I am used to in other electronic are normally safe to handle, even when opened.
Is there a reason why you attach the cerbo power cables to the battery directly and not to the lynx/distributor connections - in your picture? I just screw/attach them on top of an existing connection of the batteries.
I am also reluctant to sacrifice a busbar connection for that extra fuse-holder of the small fuse.
The goal is not to have any properly unfused wire, not even a short one.
The busbar position is indeed expensive. I agree. In my situation the position was free.
The small fuse is also feeding other sources via a small dc-dc converter. Cerbo, Ethernet switch, cabinet light, some relais are working on 12Volt. The 12 volt is ‘or’ wired with a 12V power supply from mains. This makes possible all small electronic stuff stays powered if either battery or grid is available. Handy for maintenance.
Well I would totally agree, however the general advice is to only fuse the plus/positive wire.
Reason is to keep the negative/minus wire(s) attached at all times. If not (i.e. when its fuse blows), without a direct connection to negative/minus, there will we a current flow via the network/ve.bus connections, hence killing these components.
I think this is mentioned even in the docs somewhere…or has been given in one of the installer videos (can’t remember atm, I am balding fast 
).
Again, I see no technical flaw in your solution but also do not see a disadvantage in the existing solution of the cerbo. If connection and fuse is used for more than one device, this changes the maths and makes it more convenient to maintain. So definitely a plus.
I agree to fuse only positive sides. Grounding paths can be avoided but appear to avoid expensive isolation circuits. A pity indeed to spend on the Lynx a high current position for a small fuse.
The Cerbo power cord has about 300mm un-fused wire. The wire has also a single isolation layer and is rather thin and physical vulnerable.
All that, I think, is not a safe solution.
Well, yes…the risk is dependent on the environment, where this installation is in, isn’t it?
A rocking boat or mobile RV is definitely something different from a stone-wall cellar or an insulated (but vented) steel container at home.
I never saw an installation standard were un-fused wire was accepted. Also in static environments.
Even a small risk is usually considered as unacceptable. A service engineer could make a mistake, an isolation could be damaged, etc… All single faults are supposed to be dealt with.
if it works, it works …