Arnold Howard on sat 25 mar 00
Ray mentioned cleaning Kiln Sitter contacts (below).
Suggestion: clean them with a pencil eraser. They will
last longer.
Arnold Howard
--- Ray Aldridge wrote:
> ----------------------------Original
> message----------------------------
> At 06:11 PM 3/23/00 EST, you wrote:
> >----------------------------Original
> message----------------------------
> >When troubleshooting electric kilns, consider
> anything that happened,
> >and anything you've done.
>
> (snipped very good advice)
>
> >
> >Kiln sitters (mechanical ones) are on or off
> affairs, so it's not likely
> >to be the source of the problem, unless it's
> electronic and kinky.
>
> Just a data point-- I had trouble with one of the
> contact surfaces on one
> old kilnsitter-- one of the element circuits failed
> in midfiring, and since
> the elements were almost new, I looked elsewhere.
> When I took the
> kilnsitter apart, one of the contact leaves was so
> badly pitted from arcing
> that it was no longer working. I sanded down both
> sides of the contact,
> and it started working again, but eventually I'll
> have to replace the
> contact, which is not very expensive.
>
> Ray
>
> Aldridge Porcelain and Stoneware
> http://www.goodpots.com
>
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GSM_ENT on tue 28 mar 00
Hi Ray!
When repairing a kiln component it is imperative to find out the cause for
the damage. Just to make a repair does not garantee that it will not happen
again, however, if you find out why it happened you can take corrective
action to prevent recurrence.
In the case of kiln sitter points damage it is important to remember that
this is caused by the arc-ing due to the approximation of electrical points
with electricity on one side and a closed circuit on the other. You should
ALWAYS start with your electric kiln switches in the off position,push the
plunger first and THEN turn your switches. The arc-ing effect will then be
transfered to tjhe switches (cheaper) which are designed to take more of
this action than the contactor (kiln sitter switch). This should be done
also for safety-should you push the plunger having the switches in any other
position but off, at the time that there is a high spike in the electrical
current the contactor could blow up and take your finger. Be safe! push the
plunger first and then tunr the switches.
For more information concerning this topic please contact me directly at my
private E-Mail; GSM_ENT@MSN.COM
Manuel R A "Tony" Diaz Rodriguez
MAJ., US Army (Ret.)
Master Kiln Repair Technician
Multi-Factory Trained - Senior Kiln Repair Educator
Multi-Company Product Certified Teacher
----- Original Message -----
From: Arnold Howard
To:
Sent: Saturday, March 25, 2000 8:31 PM
Subject: Re: Electric kiln problem: Kiln sitter contacts
> ----------------------------Original message----------------------------
> Ray mentioned cleaning Kiln Sitter contacts (below).
> Suggestion: clean them with a pencil eraser. They will
> last longer.
>
> Arnold Howard
>
>
> --- Ray Aldridge wrote:
> > ----------------------------Original
> > message----------------------------
> > At 06:11 PM 3/23/00 EST, you wrote:
> > >----------------------------Original
> > message----------------------------
> > >When troubleshooting electric kilns, consider
> > anything that happened,
> > >and anything you've done.
> >
> > (snipped very good advice)
> >
> > >
> > >Kiln sitters (mechanical ones) are on or off
> > affairs, so it's not likely
> > >to be the source of the problem, unless it's
> > electronic and kinky.
> >
> > Just a data point-- I had trouble with one of the
> > contact surfaces on one
> > old kilnsitter-- one of the element circuits failed
> > in midfiring, and since
> > the elements were almost new, I looked elsewhere.
> > When I took the
> > kilnsitter apart, one of the contact leaves was so
> > badly pitted from arcing
> > that it was no longer working. I sanded down both
> > sides of the contact,
> > and it started working again, but eventually I'll
> > have to replace the
> > contact, which is not very expensive.
> >
> > Ray
> >
> > Aldridge Porcelain and Stoneware
> > http://www.goodpots.com
> >
>
> __________________________________________________
> Do You Yahoo!?
> Talk to your friends online with Yahoo! Messenger.
> http://im.yahoo.com
David Woodin on wed 29 mar 00
The kiln sitter was suppose to be a high limit safety to prevent the kiln
from overfiring. The sitter contacts would last longer if the sitter was
used as a safety and not to terminate each firing. In other words use
witness cones and shut the kiln off manually or let the computor shut the
kiln off.
David
GSM_ENT on fri 31 mar 00
Hi David!
Mr Dawson invented the kiln sitter to keep himnself from being a human kiln
sitter. Being a mechanical engineer he got tired of "baby sitting" the kiln
for his wife so he came up with the original version-no Safety of Limit
Timer.
the idea is to have the kiln sitter shut off the kiln at the right time-the
proper cone/temperature or heatwork. If the sitter is properly calibrated
and the "DELTA" of the kiln (difference between the firing cone and the
witness cone in the shelf) is properly assessed and compensated for, the
sitter will turn off the kiln properly. There is no need to keep looking at
the witness cones once the aforementioned procedures have been conducted.
The Safety of Limit Timer was addes to the first version of the kiln sitter
after the first meltdown. Since the positioning of the shelves is critical
and the possibility of having a piece jamming the sensor rod of the tube
assembly of the kiln, the Safety or Limit Timer Motor was added to the
system.
In the case of "computerized" kilns the kiln sitter is in fact used as a
high end safety system. Normally the manufacturer recommends to use a firing
cone 2 values higher than the desired cone to be fired. This is just in case
something happens to the controller and the kiln becomes a "runaway" kiln.
In that case the kiln sitter will then shut it off.
Regards,
Tony
----- Original Message -----
From: David Woodin
To:
Sent: Wednesday, March 29, 2000 1:53 PM
Subject: Re: Electric kiln problem: Kiln sitter contacts
> ----------------------------Original message----------------------------
> The kiln sitter was suppose to be a high limit safety to prevent the kiln
> from overfiring. The sitter contacts would last longer if the sitter was
> used as a safety and not to terminate each firing. In other words use
> witness cones and shut the kiln off manually or let the computor shut the
> kiln off.
> David
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