Rio Grande melt furnace problems

Jewelry Discussion
1

Has anyone else experienced a problem with the fuse in this unit? On
2 occasions the fuse has blown and the fuse got so hot before it blew
that it melted the fuse holder. If so, have you found a way to avoid
this problem, or what causes it? Rio Grande has been very helpful
with replacing the unit but it is still very frustrating to have a
burnout all ready to go and then not have any metal to pour.

Thanks,
Rick

2

Hi Rick

I’m not familiar with the unit you mentioned. However the problem
described is one that can & has occurred in many devices that use
replaceable fuses.

If I had to guess, I bet the fuses used were the cartridge type
fuses. They could be either the glass or the fiber type.

What is happening is there is a poor electrical connection between
the fuse & the fuse holder. This poor connection can be caused by a
couple of things.

  1. The ends of the fuses may be dirty or corroded little; this will
    cause a poor connection. Before installing the fuse clean off the
    ends with fine sandpaper or steel wool.

  2. The inside of the fuse holder may also be dirty or corroded.
    Before inserting a new fuse, clean the inside of the fuse holder with
    fine sand paper. I wouldn’t use steel wool here as any strands left
    behind could cause a short or other problems.

  3. Another thing that could cause the problem is insufficient
    tension in the ends of the fuse holder. This could be caused by
    repeated insertions/removal of fuses or inadvertently spreading the
    sides of the fuse holder when fuses are inserteted/removed. To
    correct this problem use a pliers to squeeze the two sides of the
    fuse holder together a little.

  4. It’s also possible that the fuse holder was improperly made &
    didn’t have enough hardness to provide the tension required. Once the
    fuse holder has been used this is cause is impossible to determine.

Dave

3

Many times when I find a fuse like that it’s due to heating caused
by a poor connection, maybe it’s weak fuse clips, or corrosion. Also
some electric heat elements can short midpoint and still heat but
draw abnormal amperage, shorts to ground, shorts to another element,
etc. This usually happens only with the “spring coil” style, not
with the encased tube stlye.

HTH
Dan Wellman

4

Dave,

Thanks for the response. I’m not an electrical engineer but I am kind
of handy. This unit uses the common glass automotive type fuse (glass
15 amp). What happens is it works fine for about 10-15 times then
blows/melts. When I pry the fuse out of it’s melted carrier the ends
appear clean. It seems to me that some component/connection is
deteriorating with each use until it self destructs. Question? If the
metal clips that hold the fuse where not a heavy enough gauge metal
could they say, break down with each use?

Thanks.
Rick

5

Hi Rick,

Thanks for the response. I'm not an electrical engineer but I am
kind of handy. This unit uses the common glass automotive type fuse
(glass 15 amp). What happens is it works fine for about 10-15 times
then blows/melts. When I pry the fuse out of it's melted carrier
the ends appear clean. It seems to me that some
component/connection is deteriorating with each use until it self
destructs. Question? If the metal clips that hold the fuse where
not a heavy enough gauge metal could they say, break down with each
use?

Trying to diagnose a problem such as this on site can be problematic,
long distance it’s impossible.

In answer to your question, the clips are probably heavy enough, but
if they heat up while the unit is on they could loose some of their
temper. Repeated heatings would cause them to loose more over time.

If you don’t have any luck determining the cause of the problem
yourself, you might have some one experienced in working with
electrical appliances have a look at it.

Dave.

6

Rick and All,

My apologies for the delayed response, I’m teaching and away from my
everyday routine. But I just want to make everyone aware this
situation does have our attention and our repairs department is
working with the vendor to resolve this problem as quickly as
possible. It does only seem to be only effecting a small percentage
of these tools but if anyone else is having problems please call
800-545-6566 and ask to speak to our repairs department, this will
get you a quick response. I’ll be happy to share the resolution as
soon as one is made available to me.

Rick, I’ll make sure someone in our repair department contacts you
ASAP.

Sincerely,

Thackeray Taylor
Rio Grande Technical Support
800-545-6566
505-839-3000 ex 13903
technicalsupport@tbg.riogrande.com