30 amp fuse failure

[KINDOY2]

After reading docc's original post on this I liked the idea he had and the way he did it so I went out and looked at the 30 fuse receptacle on my Greenie , even though it was still functioning  it was indeed burnt and starting to disintegrate ..so looking to head off a future issue I followed docc's link for the aircraft breaker mod and ordered one up, and then try to copy his install ....fun little project and satisfying as well!!

[gstallons]

I will never figure out running this important of a circuit through an ATC fuse . 2020 hindsight , I suppose ?

[ferguzzi]

So I spent the winter and spring doing up the tenni as it needed some TLC.

I didn't touch electrics, it was mostly painting and fitting stainless where ever I could. I also fitted a new alloy tank.

Amazingly, it all worked when I stuck it all back together again, but the 30amp fuse has melted. Twice. Never done this before.

So, all things being equal, I’ve done something wrong. I though maybe I had painted over the ground behind the seat release keyhole, but it’s clean.

from what I’ve read above there’s a ground from the alternator via the regulator to the battery? Or did I get that wrong? Where would it be attached to?

any other thoughts?

electrics aren’t really my thing.....

[docc]

The regulator does ground back to the battery through the loom to one of the ring terminals. Cleaning and treating the rings and terminals is a good idea, as is adding a ground from the regulator case to the engine or timing cover.

Also, it occurs to me to suggest conditioning the battery with an approved charger and method (assuming it is an Odyssey PC545) rather than expecting our charging system to bring a needy battery up though that pitiful little fuse.

[Kiwi_Roy]

It's probably in this thread somewhere, the reason for the 30 Amp fuse melting that is.

The cause as I see it is too much resistance in the clips holding the fuse, resistance causes heat at a current squared relationship and don't forget the current is pulsing, its not a steady DC but a pulsing DC, the peak is much higher than the average.

So saying my VII Sport welded a fuse into the holder but I was able to break it free and clean the socket up again. It never gave me another problem but I eventually replaced the regulator with a direct connect type.

Don't re-use a fuse that has overheated toss it and replace with a new one.

 

[Kiwi_Roy]

On 11/2/2020 at 10:46 AM, docc said:

The regulator does ground back to the battery through the loom to one of the ring terminals. Cleaning and treating the rings and terminals is a good idea, as is adding a ground from the regulator case to the engine or timing cover.

Also, it occurs to me to suggest conditioning the battery with an approved charger and method (assuming it is an Odyssey PC545) rather than expecting our charging system to bring a needy battery up though that pitiful little fuse.

The problem is this wire has too much resistance, it has to carry the same 30+ Amps peak current as the Red positive wire from the battery back through the regulator to the other end of the stator winding.

The Red positive wire can afford a few Volts drop, the Voltage regulator takes care of that but the Black Negative cannot afford any Voltage drop, half a Volt there is taken directly from the battery Voltage Reference.

Remember the voltage regulator is hanging on a bracket that's not even grounded properly, just accidentally grounded where the paint scrubbed off. A short wire from the regulator case to a timing cover screw is like a massive cable through the mass of the engine/gearbox to the fat battery ground.

It's only the earlier Ducati Energia regulators that need grounding, the later bikes have a direct connected regulator as shown, item (22)

 

[ferguzzi]

Thanks for all this, I’m still a bit in the dark to be honest. 
it might be only a coincidence, but I don’t really get why painting the engine casing and a few other bits would suddenly trigger the fuse to melt. Twice.

the fuse holder is now damaged beyond repair where the 30a fuse is held so I’ll have to separate the 30a fuse away from the original holder. I like the CB idea, but probably won’t be able to get hold of one.
(I fly 787s, and we don’t even have access to them in the cockpit anymore!)

I thought maybe I’d find a damaged or disconnected wire somewhere due to my clumsiness, but nothing obvious so far.

may be time to call in a professional.....

[gstallons]

No , now is the time to check , clean and make all ground connections PERFECT . Grease , shakeproof washers , the works . IDK if this is the culprit , but it is a place to start .  With the terminals done , you need to trim back to good wire and install a new device .

What do you have access to ? The CB is the premium way to go ! 

[docc]

+1 on gstallons advice, no matter what direction you go with this.  Seems if you have to replace the fuse connectors anyway, the CB is the way to go. The 30 amp Tyco looks available:

https://www.aircraftspruce.com/catalog/elpages/pbcircuitbrkr.php

I still wonder if the Tenni's battery had gone rather flat over a long time and the charging system had to way overheat those tiny fuse connections to bring it up, along with the various connecting points having gotten corrosive. In other words, that there is nothing actually broken, pinched, shorted or really "wrong" after the reassembly.

[al_roethlisberger]

On 11/8/2020 at 10:19 AM, Kiwi_Roy said:

The problem is this wire has too much resistance, it has to carry the same 30+ Amps peak current as the Red positive wire from the battery back through the regulator to the other end of the stator winding.

The Red positive wire can afford a few Volts drop, the Voltage regulator takes care of that but the Black Negative cannot afford any Voltage drop, half a Volt there is taken directly from the battery Voltage Reference.

Remember the voltage regulator is hanging on a bracket that's not even grounded properly, just accidentally grounded where the paint scrubbed off. A short wire from the regulator case to a timing cover screw is like a massive cable through the mass of the engine/gearbox to the fat battery ground.

It's only the earlier Ducati Energia regulators that need grounding, the later bikes have a direct connected regulator as shown, item (22)

 

 

Does anyone know which years benefit from grounding the regulator to the engine case, and at what year they started including a direct path to the negative battery terminal instead?

 

 

And @docc  ...checking in at not quite your 2025 checkpoint, but in 2023 the CB is still working fine?

 

Also, as I assume the CB isn't waterproof; have you had any issues related to water getting into the CB?  Given the years and miles you've put on the bike since installing the CB, I think your attestation that water hasn't been an issue would definitely be a "good enough" determination that water shouldn't be a concern  

 

[Chuck]

Al, as far as I know, all Ducati regulators benefit from a dedicated ground wire. I *think* the last V11S models had one, but an extra can't hurt.

[al_roethlisberger]

4 hours ago, Chuck said:

Al, as far as I know, all Ducati regulators benefit from a dedicated ground wire. I *think* the last V11S models had one, but an extra can't hurt.

 

Thanks!

 

@docc  It didn't seem clear, or perhaps I missed it, but did you also end up running a larger gauge wire to/from the CB directly to/from the regulator, or fuse block, or... ?

[docc]

1 minute ago, al_roethlisberger said:

 

Thanks!

 

@docc  It didn't seem clear, or perhaps I missed it, but did you also end up running a larger gauge wire to/from the CB directly to/from the regulator, or fuse block, or... ?

So, last question first: No change to the charging wire other than removing the termination from the fuse block and extending it to to the circuit breaker.

The circuit breaker has been in service over eight years, almost 30,000 miles/ 18.500km with no issues. It has never tripped and I have used it repeatedly as a service switch to isolate the regulator from external battery charging (a procedure of debatable necessity, but I do it still). The case of the circuit breaker looks weather resistant, but IDK if it is sealed and TYCO makes no claim to waterproofness, although there are stated humidity and salt spray ratings. Where I have it mounted, tucked into the tail cowl behind the fuse block, it has never gotten wet. Even in that Kentucky Frog Strangler we once rode all day in . . .

As chuck said, all Ducati Energia benefit from a robust ground strap from its case to to the timing chest/engine. While all V11 wiring harness have a ground to the regulator, it is far too small and travels the entire loom back to the battery, defeating its effectiveness. All V11 benefit from enhancing the grounds, both this one and, very especially, the main ground to the back of the gearbox behind the seat latch:

 

[al_roethlisberger]

2 hours ago, docc said:

So, last question first: No change to the charging wire other than removing the termination from the fuse block and extending it to to the circuit breaker.

The circuit breaker has been in service over eight years, almost 30,000 miles/ 18.500km with no issues. It has never tripped and I have used it repeatedly as a service switch to isolate the regulator from external battery charging (a procedure of debatable necessity, but I do it still). The case of the circuit breaker looks weather resistant, but IDK if it is sealed and TYCO makes no claim to waterproofness, although there are stated humidity and salt spray ratings. Where I have it mounted, tucked into the tail cowl behind the fuse block, it has never gotten wet. Even in that Kentucky Frog Strangler we once rode all day in . . .

As chuck said, all Ducati Energia benefit from a robust ground strap from its case to to the timing chest/engine. While all V11 wiring harness have a ground to the regulator, it is far too small and travels the entire loom back to the battery, defeating its effectiveness. All V11 benefit from enhancing the grounds, both this one and, very especially, the main ground to the back of the gearbox behind the seat latch:

 

 

Thanks for the quick response!

 

@doccAnother quick question just to clarify:  To install the CB, did you literally just pull out the spade connectors from the 30A location in the fuse block, cut off the female fuse spade connectors, and then wire the CB serially where the fuse had been?

 

 

[docc]

2 hours ago, al_roethlisberger said:

 

Thanks for the quick response!

 

@doccAnother quick question just to clarify:  To install the CB, did you literally just pull out the spade connectors from the 30A location in the fuse block, cut off the female fuse spade connectors, and then wire the CB serially where the fuse had been?

 

 

Well, I had already attempted to wire in an ATC fuse holder, and then a MAXI fuse holder, outside the fuseblock.  The location of the circuit breaker's connections back under the tail cowl required an extension of the nefarious little green/red charging wire from the regulator and I built a larger gauge new wire connection from the circuit breaker to the battery. Not that adding a bigger wire downstream from smaller one helps in any way . . .