Fred Parker on fri 18 apr 08
I recently got an L&L e23t-3. I thought the transition from a manual
Skutt would be easy, but it turns out there is more to it than I thought.
When firing a program that includes a couple of downfire segments I've
been getting an error indicating an excessive temperature difference
between two thermocouples during the fast cool segment (500F/hr from ^6 to
1900F.) Apparently the middle zone cools slower than either the top or
bottom. Eventually the difference between the middle and top reaches 50F
and the controller gets an error/shuts down.
To remedy this I have been stacking the kiln VERY loosly -- only a bottom,
middle and top shelf -- basically two elements between each two shelves.
This helps in that it still gets close to the 50F difference, but not
quite there. L&L helped me reset the controller to average the three temp
readings instead of reading the actual temperature. This should even it
out somewhat, but I am wondering If others with this kiln have to fire
with this stacking arrangement. I do some small items (maybe 2" tall) so
having to load only three shelves gets terribly inefficient.
I thought a three-zone controller meant the computer read temperatures of
the three zones and supplied (or withheld) power as needed to maintain
even heat distribution. My problem happens when the kiln is essentially
in "free fall" from one temp to a lower temp where it does not need any
power at all. I would assume that under this circumstance if the kiln
isn't cooling as fast as the program specifies, then it would just wait
until one or more thermocouples reaches the target temperature, then
switch back in. Apparently, this is not the case. Does this mean I have
to second-guess maximum possible cooling rate based on ambient conditions
for each firing and program accordingly? I certainly hope not.
If anyone has experience with this kiln and controller I would be most
grateful for advice.
Thanks,
Fred Parker
Alisha Clarke on sat 19 apr 08
Hi Fred,
I have the very same kiln and haven't experienced that problem at all. It
has remained very consistent across the zones.
Do you have a kiln vent on the kiln? If not, that could help even it out.
Alisha
On Fri, Apr 18, 2008 at 10:39 PM, Fred Parker wrote:
> I recently got an L&L e23t-3. I thought the transition from a manual
> Skutt would be easy, but it turns out there is more to it than I thought.
> When firing a program that includes a couple of downfire segments I've
> been getting an error indicating an excessive temperature difference
> between two thermocouples during the fast cool segment (500F/hr from ^6 to
> 1900F.) Apparently the middle zone cools slower than either the top or
> bottom. Eventually the difference between the middle and top reaches 50F
> and the controller gets an error/shuts down.
>
> To remedy this I have been stacking the kiln VERY loosly -- only a bottom,
> middle and top shelf -- basically two elements between each two shelves.
> This helps in that it still gets close to the 50F difference, but not
> quite there. L&L helped me reset the controller to average the three temp
> readings instead of reading the actual temperature. This should even it
> out somewhat, but I am wondering If others with this kiln have to fire
> with this stacking arrangement. I do some small items (maybe 2" tall) so
> having to load only three shelves gets terribly inefficient.
>
> I thought a three-zone controller meant the computer read temperatures of
> the three zones and supplied (or withheld) power as needed to maintain
> even heat distribution. My problem happens when the kiln is essentially
> in "free fall" from one temp to a lower temp where it does not need any
> power at all. I would assume that under this circumstance if the kiln
> isn't cooling as fast as the program specifies, then it would just wait
> until one or more thermocouples reaches the target temperature, then
> switch back in. Apparently, this is not the case. Does this mean I have
> to second-guess maximum possible cooling rate based on ambient conditions
> for each firing and program accordingly? I certainly hope not.
>
> If anyone has experience with this kiln and controller I would be most
> grateful for advice.
>
> Thanks,
>
> Fred Parker
>
>
--
~~~~~~~~~~~~~~~~~~~~~~~~~
Alisha Clarke
Pottery by Leesh: www.alishaclarke.com
Pottery Basics: www.potterybasics.com
Elizabeth Priddy on sat 19 apr 08
your manual will address something they call
"lag" between thermocouples and how to set it.
It needs to be a bigger number, greater than 50 degrees.
But that seems to be where you will find yoru solution.
This is just a guess.
E
Elizabeth Priddy
Beaufort, NC - USA
Natural Instincts Conference Information:
http://downtothepottershouse.com/NaturalInstincts.html
http://www.elizabethpriddy.com
http://www.flickr.com/photos/7973282@N03/
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Susan Fox Hirschmann on sat 19 apr 08
You can call Rob in CA...their tech guy and talk him thru it...
He is a great help to all your "issues" with the learning curve with the L
&L. I've had mine for a couple of yrs and still learning about it!
Best of luck!
Susan
Annandale,VA
**************Need a new ride? Check out the largest site for U.S. used car
listings at AOL Autos.
(http://autos.aol.com/used?NCID=aolcmp00300000002851)
Arnold Howard on mon 21 apr 08
From: "Fred Parker"
Does this mean I have
> to second-guess maximum possible cooling rate based on
> ambient conditions
> for each firing and program accordingly?
Fred, it sounds like the center section of the kiln cannot
cool as fast as you have programmed. Have you tried a slower
cooling rate?
The Sentry 2.0 controller that we use shuts off deviation
alarms for a segment that has a rate of 9999. Maybe the
Bartlett works the same way.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
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