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Author: paul cpaul c Date: Jun 15, 2008 16:42
I presume on most bikes that have a battery and negative ground that the
main fuse, 10 amps or bigger, is always on the positive side, I guess to
help protect the battery from meltdown or explosion. Never having seen
a bike with positive ground and not having paid attention to father's
old A40 Austin, I'm guessing that even negative ground systems have a
main fuse on the positive side. Is this so?
(Maybe not a very important question, I admit, just something I keep
wondering about.)
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Author: Project Magnet #1Project Magnet #1 Date: Jun 15, 2008 17:23
paul c wrote:
> I presume on most bikes that have a battery and negative ground that the
> main fuse, 10 amps or bigger, is always on the positive side, I guess to
> help protect the battery from meltdown or explosion. Never having seen
> a bike with positive ground and not having paid attention to father's
> old A40 Austin, I'm guessing that even negative ground systems have a
> main fuse on the positive side. Is this so?
No, positive ground systems put the fuse on the negative wire.
Les
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Author: Who Me?Who Me? Date: Jun 15, 2008 17:58
"Project Magnet #1" cox.net> wrote
>>I'm guessing that even negative ground systems have a
>> main fuse on the positive side. Is this so?
>
> No, positive ground systems put the fuse on the negative wire.
>
Thanks for answering the question he THOUGHT he was asking !! ;-)
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Author: paul cpaul c Date: Jun 15, 2008 18:34
Who Me? wrote:
>
> "Project Magnet #1" cox.net> wrote
> >>> I'm guessing that even negative ground systems have a main fuse on
>>> the positive side. Is this so?
>>
>> No, positive ground systems put the fuse on the negative wire.
>>
>
> Thanks for answering the question he THOUGHT he was asking !! ;-)
>
>
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Author: Project Magnet #1Project Magnet #1 Date: Jun 15, 2008 19:27
paul c wrote:
> Who Me? wrote:
>>
>> "Project Magnet #1" cox.net> wrote
>>>>>> I'm guessing that even negative ground systems have a main fuse on
>>>> the positive side. Is this so?
>>>
>>> No, positive ground systems put the fuse on the negative wire.
>>>
>>
>> Thanks for answering the question he THOUGHT he was asking !! ;-)
>>
>>
>
> Thanks to Project Magnet, yes, but even if it makes me sound dumb, I was
> really thinking that the fuse would be nearest the positive terminal in
> both systems. My reason had to do with what I take to be the actual
> direction of current, as opposed to the so-called conventional
> direction. Perhaps it's simplistic but I reasoned that for protecting ...
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Author: Project Magnet #1Project Magnet #1 Date: Jun 15, 2008 19:28
Who Me? wrote:
>
> "Project Magnet #1" cox.net> wrote
> >>> I'm guessing that even negative ground systems have a main fuse on
>>> the positive side. Is this so?
>>
>> No, positive ground systems put the fuse on the negative wire.
>>
>
> Thanks for answering the question he THOUGHT he was asking !! ;-)
I read enough to know what he was asking, just not enough to read what
he was asking...
Les
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Author: Dr Ivan D. ReidDr Ivan D. Reid Date: Jun 16, 2008 00:39
On Mon, 16 Jun 2008 01:34:04 GMT, paul c
wrote in :
> My reason had to do with what I take to be the actual
> direction of current, as opposed to the so-called conventional
> direction. Perhaps it's simplistic but I reasoned that for protecting
> components, it might be better to fuse them 'before', as it were, they
> reach the current reaches them. (Physics is not my talent, but liking
> bikes, I can't avoid electrical theory.)
No, current flow is essentially instantaneous, electrons/holes
moving around the whole circuit in concert. The individual charge carriers
don't move quickly but the current as a whole moves near to the speed of
light.
--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. Ivan.Reid@[ brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".
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Author: Who Me?Who Me? Date: Jun 16, 2008 06:27
"Project Magnet #1" cox.net> wrote
> A fuse on the grounded + side of the circuit won't protect against short
> circuits on the - side.
>
Utterly ridiculous. Of course it would.
It takes a complete circuit for current to flow; doesn't make any difference
WHERE you open it.
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Author: Claude Hopper (11) 5. ?Claude Hopper (11) 5. ? Date: Jun 16, 2008 08:28
paul c wrote:
> I presume on most bikes that have a battery and negative ground that the
> main fuse, 10 amps or bigger, is always on the positive side, I guess to
> help protect the battery from meltdown or explosion. Never having seen
> a bike with positive ground and not having paid attention to father's
> old A40 Austin, I'm guessing that even negative ground systems have a
> main fuse on the positive side. Is this so?
>
> (Maybe not a very important question, I admit, just something I keep
> wondering about.)
The reason you disconnect he negative ground side of a battery first is
if the wrench touches the frame no sparks will result whereas if you
disconnect the positive side first and the wrench touches the frame, El
Sparko will show up. A positive ground system would be the...
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Date: Jun 16, 2008 17:55
>Thanks to Project Magnet, yes, but even if it makes me sound dumb, I was
>really thinking that the fuse would be nearest the positive terminal in
>both systems. My reason had to do with what I take to be the actual
>direction of current, as opposed to the so-called conventional
>direction.
That's why the fuse goes in backwards on positive grounded systems ;)
>Perhaps it's simplistic but I reasoned that for protecting components,
These fuses don't protect the components, they protect the wiring.
>it might be better to fuse them 'before', as it were, they
>reach the current reaches them.
Current is continuous all the way around. To answer without getting
long winded, for your example, it doesn't matter where the fuse is.
And you don't want to fuse the grounded side, as that just
leads to problems and lack of protection.
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