Arnold Howard on thu 6 jul 06
From: "Ivy Glasgow"
> I have an older Paragon SNF-24 kiln, which has been
> working well, but
> recently the lower part of the kiln has been extremely
> underfired.
> With the way that the Paragon kiln is set up, each switch
> controls
> every third element. So there are no 'zones' like in some
> kilns... I
> would expect that if a switch or whole circuit was out,
> the whole kiln
> would underfire?
Ivy, the SnF-24 elements are wired like Christmas tree
lights, as you suggested. If one element burned out, 1/3 of
all the elements in the kiln would be out.
Here is an easy way to check the elements in the kiln: Turn
the top switch (an infinite control) to High. Put time on
the switch-timers (switches 2 and 3), then turn clockwise
until they each click on. All the elements should now be
firing. Let the kiln heat up until the elements glow. Lift
the lid half an inch. Are the elements in the top three
grooves glowing? If so, all the elements in the kiln are
firing.
The center-section elements will probably not be glowing.
Nevertheless, they are still firing. They are cooler than
the top and bottom elements, so they don't begin to glow
until later.
The elements are once-around. Each brick groove has its own
element. The top brick groove holds element #1, controlled
by switch #1. The second groove holds element #2, controlled
by switch #2. The third groove holds element #3, controlled
by switch #3. The elements for each switch are wired in
series, as if the elements for that switch were actually one
continuous element. Therefore, if the elements in the top
three grooves are firing, all the elements are firing.
How many cones is the bottom section under-firing? Is this
the first time you've fired the kiln? What are the ohms of
the bottom elements? Perhaps someone installed cooler center
elements in the bottom of the kiln.
By the way, Mel mentioned that even if the elements have the
correct ohms, they may be worn. He is right. This is because
it is difficult to gauge element life with an ohmmeter. A
more accurate way to gauge element life is to keep a record
of firing times.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
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