RV-10 Firewall Mounted Fuse?

[AmontgoRV]

I bought a used 2015 RV-10 with about 300 hours on it. So far, I have flown an incremental 50 hours or so. The other day the whole panel started flickering on and off while the aircraft was running. After shutting down, I traced the main 8-gauge electrical wires from the breaker panel to an 80-amp fuse mounted on the firewall. I noticed that the fuse had cracked from engine vibration, causing the electrical system to flicker. See attached photos.

I have never seen this before. Is it normal to have an 80-amp fuse mounted on the firewall? Has anyone else seen this design before? I am tempted to just bypass the fuse permanently since it is now a known weak point in the electrical system design and I don't see why it would be useful.

Thoughts? Any better solutions out there?

 

[Auburntsts]

I have 2 ANL fuses (one for each alternator) mounted on the firewall and no issues in 530 hrs.

 

[mburch]

Current limiters mounted on the firewall are very common, and not generally prone to failure.

It looks like these cables are not affixed to anything but the fuse holder, meaning that any cable flex/vibration is transferred to the fuse. If this was my airplane I'd put a nutplate on either side of the fuse holder (annoying but certainly doable on a finished airplane) and secure all the cables with adel clamps.

 

[Carl Froehlich]

I also suggest terminal booties over those bare terminals.

Carl

 

[dmattmul]

All good suggestions

Some sort of fusing or CB’s is needed on the b lead. Not sure of your avionics but a shunt or some sort of current sensing device probably also needed if not there. Most EFIS systems have accommodations for these. The ANL looks a little cheesy and insuring you have a decent quality one money well spent. (B&C sells a good quality unit) I’ve got 2 on my firewall with shunts and almost 500 hours no issues. Good luck and welcome !

 

[MJarreau]

Discretion is Due

Alex,

I strongly encourage you to consider the purpose of that fuse before bypassing it. Admittedly, I know nothing of your electrical system, but if someone decided the fuse was necessary, it's in your best interest to find out why before making such a decision. because of this, if you don't have an electrical schematic, I'd make one - they're not that difficult to make.

Best of luck!
Mike

 

[Richard Connell]

That looks like a MIDI fuse.
I used two of them instead of ANLs due to space constraints.
As mentioned above, those terminals should definitely be properly insulated.
It looks to be a rather scrappy install all round to me.
That long length of b lead gooped to the firewall with RTV is very poor practice.
I’d be taking a good hard look at the rest of the routing to see where else they are inadequately secured.
I don’t mean to be critical. But if you removed that fuse and the b lead rubbed throug to the firewall or somewhere else you’re going to have a very bad day.
I’d also be asking the builder for the electrical system design schematics - if they exist. Something weird is going on there. Multiple fat wires in one side and one coming out the other. Are there two alternators on the same fuse by chance?

 

[1001001]

Alex,

I strongly encourage you to consider the purpose of that fuse before bypassing it. Admittedly, I know nothing of your electrical system, but if someone decided the fuse was necessary, it's in your best interest to find out why before making such a decision.

Chesterton's Fence is always worth consideration.