Wilkinson on mon 16 jun 97
Lori Wilkinson
Roswell, NM
LorWilk@dfn.com
Regarding the firing problems with my Paragon I have more information.
With a voltage tester I found there is 230 coming into the receptacle at
the plug. The plug prongs are clean and the cord does not get really hot
when firing, warm, but not hot up close to where it plugs in. The plug and
cord to the kiln seems to be in good shape. I am sure it is much newer
than the kiln. The last time I changed the elements there didn't seem to
have been any corrosion or blackening where the wires go through the wall
to the switches. There was the time before that but we changed the brass
colored metal things the elements go through (they came with the elements).
The kiln has a collar that can be easily removed if I do not need the
space. It was made for the kiln. On the kiln itself it states
"110-240-3W, watts 7200, Phase 1, 60Hz, 30 amps, and temp 2300 max." I
wonder since I use about 30 staples to keep the elements in place since
some of the brick that makes up the grove to hold the elements in place is
broken out, if they could be the cause of getting so few firings per set of
elements when I high fire?? Could pinning do that?
I sure appreciate the help. TIA
Lori Wilkinson
Paul Monaghan on tue 17 jun 97
Wilkinson wrote:
>
> ----------------------------Original message----------------------------
> Lori Wilkinson
> Roswell, NM
> LorWilk@dfn.com
>
> Regarding the firing problems with my Paragon I have more information.
> With a voltage tester I found there is 230 coming into the receptacle at
> the plug. The plug prongs are clean and the cord does not get really hot
> when firing, warm, but not hot up close to where it plugs in. The plug and
> cord to the kiln seems to be in good shape. I am sure it is much newer
> than the kiln. The last time I changed the elements there didn't seem to
> have been any corrosion or blackening where the wires go through the wall
> to the switches. There was the time before that but we changed the brass
> colored metal things the elements go through (they came with the elements).
>
> The kiln has a collar that can be easily removed if I do not need the
> space. It was made for the kiln. On the kiln itself it states
> "110-240-3W, watts 7200, Phase 1, 60Hz, 30 amps, and temp 2300 max." I
> wonder since I use about 30 staples to keep the elements in place since
> some of the brick that makes up the grove to hold the elements in place is
> broken out, if they could be the cause of getting so few firings per set of
> elements when I high fire?? Could pinning do that?
>
> I sure appreciate the help. TIA
>
> Lori Wilkinson
Hi Lori,
The staples won't have any effect as long as your not shorting out the
elements. Since you have 230 VAC and the cable doesn't get red hot your
not pulling too much current (amperage0. I would check thet the
resistance of the elements is correct and that they are properly wired
in the switch box.
First call Paragon and find out what the cold resitance of each of the
three elements should be in ohms.
At 230 volts and if you pull the full 30 amps the total resistance of
all the elemnts should be approximately 7.66 ohms. This is NOT the
resistance of each element but the total resistance. This will vary
depending on whether the elements are connected in series, parallel or
series-parallel.
First DISCONNECT the kiln from the power PHYSICALLY.
Disconnect one end of each element and measure the resistance of each
element, with an ohmmeter, from end to end of each element. The reason
for disconnecting the element is so that you don't measure a series or
parallel combination. If the resistance doesn't agree with the specs
than you may have the wrong elements. The other real possibility is
that they are incorrectly wired in the switch box.
Here's a simple analogy. If each elment was analagous to a garden hose,
the water would be the electricity, the pressure would be the voltage
and the flow rate would be the current (amperage). If you coneccted the
hoses in series the pressure would be the same but the flow rate would
be limited by the friction in the three hose (resistance). The more
hoses in series the greater the resistance and the less water out the
end (current). Now if you connected the hoses in parallel more water
would flow per unit time (greater current) because you now have 3 paths
instead of one so the resistance is much less. Now if you have greater
current (water) flow through the elements they will get hotter. Not to
bore you to death but the heat or power dissapated equals the current
squared times the resistance or P=I*2(r).
Well I hope this helps. If you need more help or questions answered
give me a shout.
Cheers,
Paul
Fir
--
Paul J. Monaghan email: paul@web2u.com
WEB2U Productions --- http://www.web2u.com
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Tadeusz Westawic on tue 17 jun 97
Wilkinson wrote:
>
> > Hi Lori,
> >
> > How many prongs on the plug, three, or four?
> >
> > Tadzu
>
> Hi Tadzu,
>
> There are 4, three flat and one round. They look clean and are not
> discolored either.
>
> Lori
Hi, Lori,
I have the same kiln, A88B. Mine was three-prong when I acquired it and
I changed it over to 4-prong myself. I have one-year-old Paragon
elements. I replaced all the brick one year ago.
My elements are not pinned-down as the docs with the elements say that
may not be necessary for ^06-04 firings. My elements don't get "bad hair
days" except where the channel, the groove in the softbrick, is broken.
Brand new elements in mine take 30-40 minutes to reach ^06 with empty
kiln on High-High from cold start. A year's use later and they take
about two hous to reach 06 on High-High from cold start. I will be
replacing them in another 4-6 months.
Before I overhauled it, I had many broken brick and many pins holding
element and broken channel in place. This was an ongoing struggle as
each firing would warp the elements more and more pins had to be added.
Sound familiar?
One day, the kiln would not reach temp. What I found was that with one
or more of the retention pins, I had made contact with the steel kiln
jacket, a "short". There were no sparks, no breakers tripping or
anything like that. My receptacle is wired to a 50-amp breaker, so the
A88B would have to be malfunctioning in the extreme before the breaker
would trip. The kiln was humming away and wasn't getting to temp. There
was some color difference from one part of the same element to another,
and I found a discoloration on the outside of the kiln jaket at the same
place. I made the necessary repairs and had no problems until the
elements got really out of hand about a month later. Then I "parked" it
and ordered the new brick and elements.
I think the A88B was originally a three-prong kiln. I think the "3W" on
the plate stands for "3-Wire". If this is correct, then it is a good
guess that the kiln jacket was not originally "grounded" and did not
matter if some pins went all the way through the brick and touched the
jacket. But someone recocnised the electrical shock hazzard when
replacing the plug and went to 4-wire, like I did. So this person
probably grounded the jacket (a good thing) so no one would get an
electric shock if they put one hand on the jacket and the other on a
sink for example, although this setup introduces other less likely
hazzards.
You keep mentioning the element retainer pins and I assume this is your
"hunch". Considering my experience above, I tend to agree with your
hunch. I think one or more of the pins is shorting somehow, maybe to the
kiln jacket. Maybe you are also plugged-in to a circuit with a 40 or 50
amp breaker, which would not be unusual in an instituion that has some
30-amp kilns and some 50-amp kilns (my Duncan electric is 50-amp). The
greater circuit capacity would allow some shorting in the 30-amp kiln
without letting you know about it by tripping the breaker.
I am posting this entire exchange of ours to the list to see what other
people of knowlege have to say about my ideas and my similar experience,
as I am but a half-baked electrician. Maybe someone knows how to use the
meter to test for a short to the jacket. I myself would probably
disconnect the jacket ground temporarily and see if the kiln went to
normal without it.
I love the small Paragon and I found the trouble and expense of relining
and element replacement to be well worth it, especially when one
considers new kiln prices.
Good Luck,
Tadzu
David Hendley on wed 18 jun 97
>At 07:41 PM 6/17/97 EDT, you wrote:
>>I think the A88B was originally a three-prong kiln. I think the "3W" on
>>the plate stands for "3-Wire".
I think the "3W" means the walls are 3" thick (3" brick instead of
2 1/2").
I also have an A88B that is "slow" and appreciate all the ideas.
David Hendley
Maydelle, Texas
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