Wiring protection ..

[Taid]

Please bear with me on this ..

When I got the bike it had 1 15 Amp fuse (at X in the diagram) ..

A FUSE CIRCUIT.JPG

Thinking about it, it seemed that the wiring was protected from the battery source but not from the dynamo ..

So OK .. fit another fuse as in position Y ..

Ah but now the main wiring is protected up to 30 Amps

Right .. put the fuse at Z ..

Fine and Dandy .. or is it ..

A fuse should be positioned as near to the source as possible to reduce the length of unprotected circuit ..

So .. should I fit 3 fuses to protect everything, and then other fuses to protect wiring with less than 15 amp capacity .. just a 15 amp at Z and risk the rest?

[Mick D]

Hi

I'm no authority on electrics but I would just keep the fuse at X, (I think mine is 10A). If you want to protect consumers with lower demands I'd run a separate circuit from the battery and fuse that accordingly. I wouldn't fuse the dynamo, it connects directly to the voltage regulator which is designed to manage it's supply.

Regards Mick

[Taid]

Hi

I'm no authority on electrics .....
Regards Mick

A greater authority than me though .. yep .. didn't think about the duties of the regulator ..

Thanks MD

[Rob Harknett]

Where is the fuse shown on your bikes wiring diagram? None of my bikes diagrams show a fuse. If I buy a battery with a fuse fitted I dump it. The manufactures never bother fitting a fuse. If you fit one and have a problem, you have made your bike non standard to the manufactures specifications. Does your insurance say fuses must be fitted ? If not, you may not be insured. Read your policy. Ask your insurer if they will pay up if you make a claim, or will refuse to pay out as you have not met with what your policy states.

[Mick D]

Hi Rob

Each to his own of course but advising against fitting a fuse for the reasons you suggest is pretty flawed.

The electrics on our bikes are in the main in excess of 50 years old, things will fail and the consequence of a battery short may well be a wire overheating and resulting fire. A discretely positioned correctly rated fuse will prevent this and any other damage to components.

I rewire my restorations as a matter of course and always incorporate fusing. I have no concerns that I may be invalidating my insurance.

Regards Mick

[Rob Harknett]

Hi Rob

Each to his own of course but advising against fitting a fuse for the reasons you suggest is pretty flawed.

The electrics on our bikes are in the main in excess of 50 years old, things will fail and the consequence of a battery short may well be a wire overheating and resulting fire. A discretely positioned correctly rated fuse will prevent this and any other damage to components.

I rewire my restorations as a matter of course and always incorporate fusing. I have no concerns that I may be invalidating my insurance.

Regards Mick

I usually consider Mick, what manufactures felt was OK, who am I to judge them wrong. Also, if insurers find a reason to get out of meeting a claim they will do so. You are also expected to disclose any modifications. I must admit, with any of my electronic equipment, I would fit a lower fuse than recommended, cheaper to replace a fuse than £100's of equipment. Fuses used very low . something milli amp. Also use quick blow instead of anti surge type. This has discover very small faults like just a loose connection.

[Greybeard]

If not, you may not be insured. Read your policy. Ask your insurer if they will pay up if you make a claim, or will refuse to pay out as you have not met with what your policy states.

Where do you draw the line, Rob? Asbestos free brake linings, nylon lined brake cables, Viton seals, stainless steel nuts, bolts, spokes and rims, halogen bulbs, unleaded fuel, synthetic or part synthetic oil, 2-pack paint? The list is endless and speculation of this sort is of no value to anyone. If youhave those concerns then contact the numerous insurance companies and then let us know the result.
Common sense suggests that a fuse in the wiring can only be a valuable safeguard. It was probably not done initially as nobody really cared enough back in the day to fit one, or the pennies saved were pennies earned

Steve

[Groily]

https://dynamoregulators.com/documents/dvr2-data.pdf

Sensible and simple minimum protection regardless of type of regulator used is shown on page 2 of the pdf here.

In that charging circuit schematic, there is just one fuse on the battery live side, covering brake light and horn as well. So the fuse needs to be quite chunky obviously. But any fuse will blow with a dead short, which is what we're really protecting against - otherwise known as 'Fire'.
Having had more than a few harnesses melt down over a lifetime, more than once owing to chafing on brake light wiring, I'm quite a believer in a separate fuse for the brake light, and the horn for that matter.

The idea that an insurer might take umbrage because someone had the sense to put a fuse where there wasn't one beggars belief. I know they'll try anything to get out of any liability, but that would take the biscuit, plus the tin.
Plenty of expert testimony to help the first poor sap caught up in litigation is contained in such as James Smith's Classic Motorcycle Electrics Manual and I'm sure there must be enough electrical engineers who'd be happy to act as expert witnesses for you Rob, when the Forces of Evil gang up on you!

[SPRIDDLER]

None of my bikes diagrams show a fuse......

Apologies to those who've seen these pics before......
Neither did Thrifty Peter's P11 wiring diagram show a fuse, but after 440 miles covered and another 350 to go en route to the 2009 International Jampot Peter's P11 came to a halt near Vittel in a cloud of smoke. The Zener diode had shorted.

Italy Jampot 2009 (5) (640x429).jpg

P11 melted wiring (640x297).jpg

I rode back on my '54 G3LS to a dealer that we had passed a few miles back where I was able to buy a 20m roll of wire (they only had blue) and Peter rewired 90% of the bike, replacing one wire at a time. About 2 hours later we rode on to our next camp site, then to the rally near Milan and back home without a problem (except for replacing his second gear pinion at the rally which had suffered a broken tooth).

It's all part of the adventure.

Italy Jampot 2009 (8) (640x429).jpg

[g80csp11]

It did have a fuze , but 15A was probably too large. the zenor failed and all power from the alternator (16A) found its way to earth any way it could
There were a few warning signs that i had ignored ie over charging battery
dont you have any pictures of anyone else Nevile ?