Searching \ for '[EE] Odd fuse failures' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=odd+fuse+failures
Search entire site for: 'Odd fuse failures'.

Exact match. Not showing close matches.
PICList Thread
'[EE] Odd fuse failures'
2006\10\13@113318 by Mike Hord

picon face
We recently had two of three new machines fail at a
customer site with fuses going out.  Not too odd, but
the mechanism of fuse failure is:  the filament became
detached at both ends of the fuse, so it was free to
roll around inside the fuse (these are the cylindrical
glass type).  Both fuses had the same role in the
machines; neither fuse is unique in the machine, but
both machines lost the same fuse and no other.

I guess the question is: Have any of you ever seen
that kind of failure mode in a fuse caused by
overcurrent?  There were no obvious signs of a "blown"
fuse- no soot inside the glass, or visible breaks in
the wire, etc.

Of course, the fuses were discarded before they
came back to me.

Mike H.

2006\10\13@114629 by M. Adam Davis

face picon face
Sounds like it may have been defective fuses and a mechanical failure.
Do you have any more fuses from the same batch?  I'd also contact the
fuse company and see if they have any idea about what the failure
could be.

-Adam

On 10/13/06, Mike Hord <spam_OUTmike.hordTakeThisOuTspamgmail.com> wrote:
{Quote hidden}

> -

2006\10\13@120941 by David VanHorn

picon face
On 10/13/06, M. Adam Davis <.....stienmanKILLspamspam@spam@gmail.com> wrote:
>
> Sounds like it may have been defective fuses and a mechanical failure.
> Do you have any more fuses from the same batch?  I'd also contact the
> fuse company and see if they have any idea about what the failure
> could be.


What rating?

could be vibration, or high inrush current.

2006\10\13@121117 by Mike Hord

picon face
These fuses came pre-installed in the common platform of our machine,
which is assembled by a CM.  I intend to contact them and see what I
can find out along those lines- fuse manufacturer (it's not obviously on
the fuse; at least, not that I can recognize), lot, etc.

It's odd to me that of eight fuses of the same type, presumably grabbed
from the same bucket of fuses during the assembly process, two failed,
and those were the same fuse on two different machines.

Mike H.

> Sounds like it may have been defective fuses and a mechanical failure.
>  Do you have any more fuses from the same batch?  I'd also contact the
> fuse company and see if they have any idea about what the failure
> could be.
>
> -Adam

2006\10\13@122753 by Bob Axtell

face picon face
M. Adam Davis wrote:
{Quote hidden}

>> --

2006\10\13@124013 by David VanHorn

picon face
>
>
> It's odd to me that of eight fuses of the same type, presumably grabbed
> from the same bucket of fuses during the assembly process, two failed,
> and those were the same fuse on two different machines.


That makes me think vibration even more.
You get nodes that vibrate a lot, and others that vibrate very little.
I've seen chips pop out of sockets, and even ceramic chips soldered in that
blew their tops.

2006\10\13@141440 by Mike Hord

picon face
> That makes me think vibration even more.
> You get nodes that vibrate a lot, and others that vibrate very little.
> I've seen chips pop out of sockets, and even ceramic chips soldered in that
> blew their tops.

Very interesting thought.  I suppose it's possible.  This isn't a new machine,
though- we've shipped dozens all over the planet and this is the first time this
has happened.

The general consensus seems to be that current related failure is not very
likely, though.

It's a 5A, 125V fuse.  Not a slow-blow, so inrush COULD be a factor.

The fuses are all mounted cheek-by-jowl on a DIN rail.

Mike H.

PS- Can anyone give me a satisfactory reason why a fuse has a voltage
rating?  It just doesn't make sense to me.

2006\10\13@142908 by M. Adam Davis

face picon face
On 10/13/06, Mike Hord <.....mike.hordKILLspamspam.....gmail.com> wrote:
> PS- Can anyone give me a satisfactory reason why a fuse has a voltage
> rating?  It just doesn't make sense to me.

The only reason I can see is that fuses are designed to very precisely
break at a single point in the fuse wire.  A higher voltage fuse must
have a longer breaking point so the voltage doesn't arc.  As a fuse
breaks a spark is drawn across the increasing gap, which also creats a
lot of explosive pressure on the fuse casing.  A higher voltage will
have a hotter, longer lasting arc.

There may be other reasons related to the materials, mechanical
connection (fuse holder), etc.

But I'm merely guessing.  Sounds good enough for cocktail parties,
though...  :-P

-Adam

2006\10\13@144243 by Mike Harrison

flavicon
face

>
>PS- Can anyone give me a satisfactory reason why a fuse has a voltage
>rating?  It just doesn't make sense to me.

It's to do with the amount of energy the fuse can handle before the case explodes.
A short on a 12v line makes the fuse go open.
A short of 240V makes it go BANG!


2006\10\13@144456 by David VanHorn

picon face
>
> PS- Can anyone give me a satisfactory reason why a fuse has a voltage
> rating?  It just doesn't make sense to me.



Above that voltage, it's not guaranteed to be able to break the circuit.

2006\10\13@150115 by peter green

flavicon
face
> It's to do with the amount of energy the fuse can handle before
> the case explodes.
> A short on a 12v line makes the fuse go open.
> A short of 240V makes it go BANG!
i thought determining the point beyond which a fuse would go bang was what
breaking capacity ratings were for

2006\10\13@150931 by alan smith

picon face
Think its because its a wattage rating.  
 
 How long were the machines running before they popped?  Have they popped again since being replaced?
------------------------------------------------------------------------------------------------------------------------
PS- Can anyone give me a satisfactory reason why a fuse has a voltage
rating? It just doesn't make sense to me.



               
---------------------------------
How low will we go? Check out Yahoo! Messenger’s low  PC-to-Phone call rates.

2006\10\13@160722 by Mike Hord

picon face
>   How long were the machines running before they popped?
>  Have they popped again since being replaced?

As far as we can tell, they weren't.  We tested them, shipped
them, they were setup at the customer site and never worked
until the fuse was replaced.

That is third hand, of course.  The folks that did the initial setup
are from a reseller.  They told our apps techs what happened,
who then discovered the fuse thing.  The apps techs told their
manager, who told me.

Mike H.

2006\10\13@162826 by Bob Axtell

face picon face
Mike Hord wrote:
>>   How long were the machines running before they popped?
>>  Have they popped again since being replaced?
>>    
>
> As far as we can tell, they weren't.  We tested them, shipped
> them, they were setup at the customer site and never worked
> until the fuse was replaced.
>
> That is third hand, of course.  The folks that did the initial setup
> are from a reseller.  They told our apps techs what happened,
> who then discovered the fuse thing.  The apps techs told their
> manager, who told me.
>
>  
Hmmm. Since you have used these in the past without problems, the
install itself is suspect.
You MIGHT not have a real problem, Mike.

> Mike H.
>  

2006\10\13@164602 by David Minkler

flavicon
face
Wouldn't you LOVE to get your hands on those fuses and see if there
really is something to this?  It's too bad that people who recognized
that the nature of the failure was extremely unusual (blown at both ends
- thought it was unusual enough to mention it) didn't have enough casual
curiosity to at least send the fuses back in case you were interested
enough to look into it.

Dave

Mike Hord wrote:

{Quote hidden}

2006\10\13@165508 by Thomas C. Sefranek

face picon face

-----Original Message-----
From: EraseMEpiclist-bouncesspam_OUTspamTakeThisOuTmit.edu [piclist-bouncesspamspam_OUTmit.edu] On Behalf Of
Mike Hord
Sent: Friday, October 13, 2006 2:15 PM
To: Microcontroller discussion list - Public.
Subject: Re: [EE] Odd fuse failures

> That makes me think vibration even more.
> You get nodes that vibrate a lot, and others that vibrate very little.
> I've seen chips pop out of sockets, and even ceramic chips soldered in
that
> blew their tops.

Very interesting thought.  I suppose it's possible.  This isn't a new
machine,
though- we've shipped dozens all over the planet and this is the first time
this
has happened.

The general consensus seems to be that current related failure is not very
likely, though.

It's a 5A, 125V fuse.  Not a slow-blow, so inrush COULD be a factor.

The fuses are all mounted cheek-by-jowl on a DIN rail.

Mike H.

If you think about it the ENDS of the fuse are the greatest heat sink
VERY unlikely to fuse there, rather in the middle where the thermal
Effect is greatest.

 *
 |  __O    Thomas C. Sefranek  @spam@WA1RHPKILLspamspamARRL.NET
 |_-\<,_   Amateur Radio Operator: WA1RHP
 (*)/ (*)  Bicycle mobile on 145.41MHz PL74.4

ARRL Instructor, Technical Specialist, VE Contact.
hamradio.cmcorp.com/inventory/Inventory.html
http://www.harvardrepeater.org


2006\10\13@170825 by Martin Baker

picon face
I have a thought on this.
I do not know the exact fuse type or shipping conditions. However there are
two things that come to mind.
1) We used to have all sorts of unexplained failures at the other end, then
we used "shock watch" sensors. Apparently, the problem was not vibration,
but the habit of the receiving dock of letting the pallets drop 6 inches to
the ground. The fuses ( granted, little tiny spring loaded things), all blew
on impact
2) I also had the unnerving experience of watching a board during a thermal
endurance test. During the bake, all the fuses failed, not because of the
absolute temperature, but because of the fact that they were mounted to a
heat sink. The heat sink actually got hot enough to fry the fuses in a hot
environment. Again these were spring loaded, and I never was told whether
the solder failed or there was a thermal expansion issue, or??? The end
result was a fan added to dissipate heat better, as I was told at the
time...

....

Where are these things being shipped to? Under what conditions?


Good luck though. Stuff like this where you aren't there and can't see the
remains of the failed part can be nearly impossible to
Puzzle out.

Regards,

Martin

{Original Message removed}

2006\10\13@170858 by peter green

flavicon
face
> the filament became
> detached at both ends of the fuse, so it was free to
> roll around inside the fuse (these are the cylindrical
> glass type).
i'd guess it was a combination of poorly manufactured fuses and
vibration/shocks during transit/commisioning.


2006\10\13@180737 by David VanHorn

picon face
>
> If you think about it the ENDS of the fuse are the greatest heat sink
> VERY unlikely to fuse there, rather in the middle where the thermal
> Effect is greatest.


Greatest thermal shock near the ends too.

2006\10\13@180956 by Howard Winter

face
flavicon
picon face
Mike,

On Fri, 13 Oct 2006 11:09:13 -0500, Mike Hord wrote:

>...
>
> It's odd to me that of eight fuses of the same type, presumably grabbed
> from the same bucket of fuses during the assembly process, two failed,
> and those were the same fuse on two different machines.

Could it be mechanical vibration setting up a resonant frequency that caused the fuses' wires to shake themselves to death?

Cheers,


Howard Winter
St.Albans, England


2006\10\13@222120 by Shawn Wilton

picon face
Let's face it people.  It could have been nearly anything that caused those
fuses to die.  It could have also been that the people installing the
machine didn't even put the fuses in.  We will never know as there are no
fuses to test.



{Quote hidden}

--

Shawn Wilton (b9 Systems)
http://b9Systems.com  <- New web page

2006\10\14@133723 by Mike Hord

picon face
There WERE fuses there.  The apps engineer pulled them and replaced
them.  He just didn't send them home for investigation.

And he didn't check OTHER fuses in the system, although they must
be working or the machine would've still be offline.

I'm leaning towards this being an incredibly unlikely series of events,
unlikely to be duplicated and probably not something we'll ever see
again.  I'm going to talk to our supplier, find out if they've heard any
complaints about "broken" fuses elsewhere, and see if they recently
changed fuse manufacturer/supplier.  Otherwise I don't think there's
much to be done- it's not a HUGE problem, since it's something
we're aware of now and if something similar happens on delivery
again, we will know right away to check those fuses.

It's good to know that nobody here has heard of this or has an "easy"
answer for it.

Mike H.

On 10/13/06, Shawn Wilton <KILLspamblack9KILLspamspamgmail.com> wrote:
> Let's face it people.  It could have been nearly anything that caused those
> fuses to die.  It could have also been that the people installing the
> machine didn't even put the fuses in.  We will never know as there are no
> fuses to test.

> > Could it be mechanical vibration setting up a resonant frequency that
> > caused the fuses' wires to shake themselves to death?

2006\10\14@203342 by Sean Breheny

face picon face
Hi Mike,

Recently at work we received a number of large industrial battery
chargers with broken fuses in them. It turned out that the fuses (one
each in perhaps 10 units) were broken by mechanical stress, probably
in shipment. The fuses were not the glass cartrige type but rather
forklift type fuses (flat fiberglass package with a mica window and
two metal tabs). We were able to determine that the two mounting
points for the fuse could move independently, thus placing mechanical
stress on the fuse. Also, the bolts holding the fuse in were
over-tightened.

So, I have seen something similar to what you are describing but it
was with a totally different type of fuse.

Sean


On 10/14/06, Mike Hord <RemoveMEmike.hordTakeThisOuTspamgmail.com> wrote:
{Quote hidden}

More... (looser matching)
- Last day of these posts
- In 2006 , 2007 only
- Today
- New search...