Robert Klander on mon 24 mar 03
Hello folks,
Another newbie with some potholes in my path...
I was in the middle of a glaze firing today, when things went south...
I have an old kiln with a dawson sitter.
My first bisc (cone 07) and glaze firing (to cone 9) went flawlessly in
December. As did the second bisc firing last Thursday.
Today, the kiln went dark before the cone dropped, about 2 hours early. I
called a potter friend (out of town) who recommended that I just let it cool
down, find out what broke, fix it, and refire to finish the glazing after
it's all fixed again.
My kiln electrician is unavailable for who knows how long, probably 10 days,
and I'm wondering if I can get a few pointers to start troubleshooting the
kiln, and maybe at least order whatever parts are needed, so that he will
have what's needed to get it rolling again when he's back in town...I'm just
a bit in the dark as to how to actually diagnose the problem.
There is power to the kiln, and it didn't throw the 60 amp breaker. . .
The timer on the sitter seemed not to be working at all today, when I was
checking it through the firing, even when the heat was obviously building.
In the other three firings, it made a sound like timer motors make. The
kiln was on low from midnight to 6:30 this morning, medium from then until
10 a.m. and then on high until around 3:30 when it didn't seem to be getting
brighter when I peeked in on my hourly checkups... Then a little after 4, it
was definitely darkening up inside. The lever had not dropped, but the
power button seemed to have popped out a bit. This was odd...I tried to
re-engage it, and although it caught for a second or two, it didn't hold.
Obviously there's now something not right with that switch...
So, after trying to reach my kiln savvy electrician friend, and talking to
my out-of-town potter friend, I just shut down the power, and am waiting for
things to cool down enough to investigate.
I thought the first step would be to check for broken elements... But after
that, I'm not sure how to proceed. As I mentioned, there's something up
with the power button, but I'm not clear on how to determine exactly what
(bad switch? faulty wire? disengaged by faulty timer somehow?)
I don't have witness cones set up, so I'm not sure how far it made it
through the firing, as temperature goes. It did seem that the glaze on the
few pieces that I could see through the top vent had developed some color,
although I couldn't really tell the surface sheen, or whether things were
completely fired, because it's still pretty hot in there...
The kiln is 240 v., 60 watts. The power to it was run by a professional
electrician. (It's in a new out building, built last fall)...
Any suggestions are greatly appreciated...(I have a basic testing meter, and
a great respect for electric power)
Many thanks,
Robert K
Michael Wendt on tue 25 mar 03
Robert wrote:
>The lever had not dropped, but the
power button seemed to have popped out a bit. This was odd...I tried to
re-engage it, and although it caught for a second or two, it didn't hold.
Obviously there's now something not right with that switch...<
This happens all the time with our kiln sitter and I believe there
is really nothing wrong. We push it in again and again until it holds. It
needs to be a little bit hair trigger to pop open when the cone sensing rod
releases the weighted latch.Before you try any repairs, see if the lights go
back on when you hold the button in manually and if they do, take some time
to re-engage the button and try firing again. If it lights but you can't get
it to stay in, you may need to contact Dawson for suggestions, such as how
to adjust or replace the component.
Just a thought...
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Avenue
Lewiston, Idaho 83501
1-208-746-3724
wendtpottery.com
Arnold Howard on wed 26 mar 03
Robert, have you discovered the problem with your Kiln Sitter yet?
2 ideas that came to me:
Your Limit Timer clock may be burned up.
A wire may be in the way of the Kiln Sitter plunger mechanism,
preventing it from locking in the on position.
Sincerely,
Arnold Howard
Paragon Industries, L.P.
www.paragonweb.com
----- Original Message -----
From: Robert Klander
To:
Sent: Monday, March 24, 2003 8:15 PM
Subject: [CLAYART] kiln troubleshooting? (A bit long)
> Hello folks,
> Another newbie with some potholes in my path...
>
> I was in the middle of a glaze firing today, when things went south...
> I have an old kiln with a dawson sitter.
> My first bisc (cone 07) and glaze firing (to cone 9) went flawlessly
in
> December. As did the second bisc firing last Thursday.
> Today, the kiln went dark before the cone dropped, about 2 hours
early. I
> called a potter friend (out of town) who recommended that I just let
it cool
> down, find out what broke, fix it, and refire to finish the glazing
after
> it's all fixed again.
> My kiln electrician is unavailable for who knows how long, probably 10
days,
> and I'm wondering if I can get a few pointers to start troubleshooting
the
> kiln, and maybe at least order whatever parts are needed, so that he
will
> have what's needed to get it rolling again when he's back in
town...I'm just
> a bit in the dark as to how to actually diagnose the problem.
> There is power to the kiln, and it didn't throw the 60 amp breaker. .
.
> The timer on the sitter seemed not to be working at all today, when I
was
> checking it through the firing, even when the heat was obviously
building.
> In the other three firings, it made a sound like timer motors make.
The
> kiln was on low from midnight to 6:30 this morning, medium from then
until
> 10 a.m. and then on high until around 3:30 when it didn't seem to be
getting
> brighter when I peeked in on my hourly checkups... Then a little after
4, it
> was definitely darkening up inside. The lever had not dropped, but
the
> power button seemed to have popped out a bit. This was odd...I tried
to
> re-engage it, and although it caught for a second or two, it didn't
hold.
> Obviously there's now something not right with that switch...
> So, after trying to reach my kiln savvy electrician friend, and
talking to
> my out-of-town potter friend, I just shut down the power, and am
waiting for
> things to cool down enough to investigate.
>
> I thought the first step would be to check for broken elements... But
after
> that, I'm not sure how to proceed. As I mentioned, there's something
up
> with the power button, but I'm not clear on how to determine exactly
what
> (bad switch? faulty wire? disengaged by faulty timer somehow?)
> I don't have witness cones set up, so I'm not sure how far it made it
> through the firing, as temperature goes. It did seem that the glaze
on the
> few pieces that I could see through the top vent had developed some
color,
> although I couldn't really tell the surface sheen, or whether things
were
> completely fired, because it's still pretty hot in there...
> The kiln is 240 v., 60 watts. The power to it was run by a
professional
> electrician. (It's in a new out building, built last fall)...
>
> Any suggestions are greatly appreciated...(I have a basic testing
meter, and
> a great respect for electric power)
>
> Many thanks,
> Robert K
>
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