Earthing in rib

[Fizzwizz]

Originally Posted by Nos4r2

It's a good reason to keep an eye on your anodes

Ha, that's the truth

[Chris Caton]

Originally Posted by Fizzwizz

Many thanks for the info. It does strike me though, that the best way to prevent these erroneous currents through metalwork is to keep your 12V circuitry away from it. i.e don't tie your negative to your engine (ground). The minute you do this you have the potential for aberrant circuits running through props/shafts etc. as you've created a path back to negative through the metalwork. Despite peoples belief, current cannot flow from the positive terminal of your battery to the sea. (This only happens with powerstation generated electricity as the powerstation bonds neutral to the ground creating a path back for current through the soil)

not that I'm any sort of an expert in the world of leccy stuff, or in anything else for that matter, but after 39+ years workin, sorry just turnin up one thing I do know is that leccy will find a path, and most probably it will be a path wot you ain't thought of!! current can and will do the most strange things, so i don't see wot wrong with with current flowing from the positive to the sea, as long as it can find a path back to the negative I think that's wots known as a circuit oh, n the other thing I know is that 240/415v don't half hurt, n up to now I av bin lucky enuff not to av found out ow much 11kv or more hurts, n I'm hoping to keep it that way too

[Nos4r2]

Originally Posted by Nos4r2

You don't have a lot of choice about that unfortunately. Battery negatives bolt directly to the powerhead. There's no avoiding it as without the negative bolted to the powerhead, you're not going to be able to generate an HT spark.

<poly moment> Actually, to be pedantic I'm not correct there-without the battery negative bolted to the powerhead, you're going to have no charging system and no power trim or electric start. You could in theory have the battery negative not bolted to the powerhead, with just the HT side of the coils having continuity to the powerhead. It'd be hideously complicated, possibly unreliable and a bastard to troubleshoot though.

STILL a good reason to keep an eye on your anodes!

</poly moment>

[Fizzwizz]

Originally Posted by Chris Caton

I av bin lucky enuff not to av found out ow much 11kv or more hurts, n I'm hoping to keep it that way too

My record (if we're comparing shark bite scars) is 27,000V from the EHT stage of an old CRT television. Not enough current to be dangerous, but a high enough potential to vapourise a pin head sized piece of skin on my ring finger.

[Nos4r2]

Originally Posted by Fizzwizz

My record (if we're comparing shark bite scars) is 27,000V from the EHT stage of an old CRT television. Not enough current to be dangerous, but a high enough potential to vapourise a pin head sized piece of skin on my ring finger.

HT lead of a bike at 7000 rpm up the inside of a wet glove at 50mph...

[Fizzwizz]

Originally Posted by Nos4r2

HT lead of a bike at 7000 rpm up the inside of a wet glove at 50mph...

Haha. That beats a bumblebee in the eye at 70mph!

[Chris Caton]

a few years back when I wuz only knee high to a rib, I went to tidy up after a bit of 33kv switchgear blew up, the bit where the fault was had sort of vaporised, not surprising till we realised that it was a piece of 1" steel plate, about 4ft square, all that was left was a load of crappy oily carbon, still kept us busy for a few months stripping the busted stuff out n fitting the new stuff, glad I wasn't paying the bill

[Poly]

Originally Posted by Nos4r2

<poly moment> Actually, to be pedantic I'm not correct there-without the battery negative bolted to the powerhead, you're going to have no charging system and no power trim or electric start. You could in theory have the battery negative not bolted to the powerhead, with just the HT side of the coils having continuity to the powerhead. It'd be hideously complicated, possibly unreliable and a bastard to troubleshoot though.

STILL a good reason to keep an eye on your anodes!

</poly moment>

As I recall my first car did something like that spontaneously in the fast lane of the M5 in the dark and the p***ing rain one night... ...it was an interesting 'coast' to the hardshoulder...