Re: (ET) Replacing main disconnect

[Chris Zach <czach computer org>]

Perhaps, however a properly designed fuse should not arc or have a problem.

The ones I am thinking about are filled with sand. When they overload, 
the arc is extinguished because the sand around the fault wire turns to 
glass.

If you go above the AIR rating the fuse will explode, however I'm pretty 
sure that flooded batteries cannot top 2,000amps in a dead short, much 
less 10,000*

Chris

* Technically the Hawker Genesis batteries in my car can short up to 
5,000amps for a second or two. With two strings it is right at the limit 
of it's main pack fuse.



RJ Kanary wrote:

> Hopefully the fuse can totally contain the ALL  results of a fault 
> opening . Having sparks and high temperature gasses present near lead 
> acid batteries, {That do evolve explosive gases during DIScharge, 
> also.}may not be the best idea in the world.
>         Again, we are faced with the fact that original engineers had 
> some darn good reasons for doing many of the things that they did. <G> 
> Fuse link INSIDE the control cabinet, AWAY from the power pack. I wonder 
> WHY they did that ? <VGB>
>
>
> ----- Original Message ----- From: "Chris Zach" <czach computer org>
> Cc: "Elec-trak list" <elec-trak cosmos phy tufts edu>
> Sent: Thursday, September 16, 2004 11:09 PM
> Subject: Re: (ET) Replacing main disconnect
>
>
> > Ok. So putting a 200amp 10,000 volt AIR DC rated fuse (say one from a 
> > large APC UPS) will do the trick. That works; most of those are rated 
> > for 48 volts anyway.
> >
> > I'll sit down over the weekend and figure out how to implement such a 
> > beast. I suppose one could put the fuse in between the battery pack's 
> > individual batteries (say between 1 and 2), however if anything goes 
> > to ground you could have part of the pack bypass the fuse. Thus it 
> > would have to go into the last battery connection itself.
> >
> > Hm.
> >
> > Chris
> >
> >
> > RJ Kanary wrote:
> >
> > >     It takes a sustained 200A load to vaporize the OEM fuse link.
> > > The switch kit that Tech Parts formerly sold retained the fuse link 
> > > by providing a piece of plastic with the switch to mount it on . As 
> > > soon as my server is restored after a domain hijacking incident, I 
> > > will scan and post the instructions that Bill had provided.
> >
> >
> >
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