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kiln controller problems - manual override needed?

updated sat 31 aug 96

 

Jack or Lori Cole on wed 21 aug 96

Hello everyone!

I recently had a problem with my electric kiln controller, and wondered
if someone out there might have some thoughts or advice....

Synopsis:
My controller (Orton Autofire) shut down the kiln 3 times with error
messages. In between it reported unrealistic temperatures (see below)
and seemed to be out of control. I had no way to _take_ control; just
had to sit and watch and hope. I am considering a manual overide so
that I never have to be at its mercy again.

Does anyone else have manual overrides on their controllers? What are
they like? Where are they hooked in?

Details:
Last week I was firing to cone 6. My kiln and controller are <1 year
old. I have fired about 6 bisques; this was my second glaze firing. I
programmed as follows:
Rate (F per hr) To Temp: Hold:
100 120
360 960
180 1140
220 2000
105 2210 20 minutes
105 2100
end
First, I received an ERR1 message a few minutes after starting. ERR1
means that the temperature was not rising at the programmed rate; the
kiln was shut down. I threw the breakers and tried again- kiln still
wouldn't start to heat. Then I switched to the preprogrammed glazed
program and it kicked in. It was up to 229 degrees F. so I reprogrammed
the first step of my user program to 360 degrees per hour up to 420
degrees, and tried it again. It started ok, but 20 minutes later there
was another ERR1. Started it AGAIN, and it behaved until just past 2030
degrees....

10 minutes later the controller read 2154 degrees, and proceeded to jump
and read erratically every few seconds. Over the next 15 minutes it
made its way down to 2065, then jumped again to 2100. 1 minute later it
had dropped all the way to 1948, and then it finally started to read
somewhat normally. It finally made it to 2210 degrees and the hold
started. Ten minutes later I had an ERR2 shutdown ("Temperature more
than 50 degrees away from set point") and a temperature of 2342 degrees.

Has anyone had a similar experience or have an idea what might have
caused these problems?

Yes, I do plan on getting the controller fixed ASAP, but still, I don't
want to ever be caught like this again. Any thoughts or experiences or
these problems or on manual overrides would be greatly appreciated.

Thanks,
Lori Cole
Kitchener, ON

Ken L Russell on fri 23 aug 96

these problems or on manual overrides would be greatly appreciated.>

If you're bisquing in your kiln, the sulfur is causing your elements to
deteriorate much quicker. Sounds like your elements can't keep up with
the rate schedule you want and if the contoller can't hold the rate you
want, it'll simply shut down causing the arror message. My Skutt
controller does the same thing. You might try a slower rate like 100
deg/hour to see if that'll work. Also, the sulfur from bisquing is
deteriorating the thermocouple, so erroneous temperature readings could
be par for the course. I'd be suspect of those two things (tired
elements, tired thermocouple) before assuming it's the controller.

Ken Russell
The Arlington Pottery
gone2pot@juno.com

don jung on fri 23 aug 96

Lori, we've had similar problems with a electric kiln controller.
Once we realized the temperature was going up and down erratically, we
shut down the kiln through the breaker panel and proceeded to fix the
controller and pyrometer probe. As it turned out, we needed to
replace the probe, adjust the controller and refire. We were told to
expect the probe to 'break' in about a year to 2 years. Lo and
behold, it 'broke' in 1.5 years. I can't remember the brand name off
hand but the symptoms are quite similar, so it's very likely the same
problem.
We've also entertained the thought of a manual override switch, but
skipped the expense and still go through the breaker panel.

:-)

Don Jung
dojun@axionet.com
Vancouver, B.C.
Canada

BobWicks@aol.com on fri 23 aug 96

Hi Lorie:
I have a similiar condition with my electronic control (Perfect Fire). I was
doing a fire when all of a sudden we got hit with summer electrical
thunderstorm and had a brief power outage. I had to rest it and it seemed
ok, however I guess I didn't look far enough. The next fire we had another
storm only this time everything in the kiln melted down including the
porcelain element holders and the shelves and some fire bricks. I did
another test and watched the degrees per hour cycle and it was all over the
charts so I ended up sending it back to the factory. Needless to say Lorie I
think it might be best to also have a kiln sitter and timer to fall back on
just in case something goes wrong. I have 4 teachers depending on our kiln
for firing class projects and this produces a lot of stress on every one
concerned.

Bob

jsproule@mars.ark.com on fri 23 aug 96

Hi,

We've got a skutt kilnmaster, and have only had that problem once - when
the thermocouple needed to be replaced. It's a good idea to have an extra
on hand so you can do your own problem solving right when you need to!
When I took out the old one, it had broken inside the ceramic sheath.

Of course, it may be a computer problem, too. Have you tried giving the
company a call? I know Skutt was really good when I called them - very
helpful.

Vickie
Hornby Island, B.C.
email: jsproule@mars.ark.com