Battery Fuses

[LORDNELSON]

I would be most grateful if a reader could point me in the right direction to locate some battery fuses designed to suppress flash etc if they function. This type of fuse is shown on page 69 of the March PBO. Thankyou

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[Miker]

I read the article in PBO after having bought some battery fuses from Index Marine. I Emailed them and got the following reply:

"Thank you for your email. I have been advised that under normal operating conditions the mega fuses (E-6051/-- range) will not spark in the event of an over current situation. However, should the fuse be subjected to a massive overload (over its breaking capacity) it may rupture and cause sparks."

I'm not sure where that leaves me, but having bought the fuses, I might as well use them.

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[pvb]

Battery fuses should be located as close as practically possible to the positive post of the battery (or battery bank). The purpose of the fuse is to protect the cable from overheating in the event of a catastrophic short. If you use Mega Fuses (made by Littelfuse and distributed under various names), they have a reasonable slow-blow characteristic. If they blow, they're highly unlikely to spark. I accidentally shorted a connection and blew one of my Mega Fuses; out of curiosity, I thought I'd have a look to see what was inside it - it took several minutes with a hacksaw to dismantle it! And always use proper Mega Fuse holders, and fit the insulating cover and cable boots.

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[LORDNELSON]

Thank you for your post. I have the Index Marine catalogue and noted that their description of the high amperage fuse did not describe them as being spark free, hence my post on this subject. The quote in your post leaves me in some doubt; one would expect a fuse (unless time delayed) to rupture at or about its breaking capacity, thus I am not sure what the phrase "should the fuse be subjected to a massive overload" means in this context, a point I gather you have appreciated! I will continue my researches and if I come across any interesting facts will come back to you.

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[pvb]

Time delayed....

Mega Fuses have a slow-blow characteristic - . They are excellent products, and I reckon all new boats should automatically be fitted with them. More general details are <A target="_blank" HREF=http://www.littelfuse.com/PDFs/TechBriefs/TB98-003.pdf>in this document.

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[steve_cronin]

Location....

...is the answer.

DON'T locate them in the battery compartment (hydrogen gassing) or the engine well (hot diesel vapour). Many boat builders locate them in some out of the way place well above a realistic possible vapour accumulation site. On our Bavaria they are located in the saloon, behind a backrest, under a side deck and well away from any conbustibles with a warning label not to stow near them.

There is a CE and an American YBSA rule for their siting.

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[steve_cronin]

Not ewishing to be sarcastic...

... of cynical but short it across a 240 Ah battery and you'll find out!

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[steve_cronin]

can\'t agree more with...

"...and fit the insulating cover and cable boots. "

The local 999 Fire Brigade rarely attend offshore!

Steve cronin

(well, it IS late!)

<hr width=100% size=1>The above is, like any other post here, only a personal opinion

 

[LORDNELSON]

Re: Not ewishing to be sarcastic...

Expensive way to find out?

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