Sean Burns on thu 2 nov 06
Greetings,
I recently received a notice from the State of Massachusetts that a
campaign is underway in the public schools to eliminate all mercury except
for some very limited laboratory instances. I run a electric kiln
manufactured by Contemporary Kiln out of California and it has 3 mercury
displacement switches in the electric box -those being manufactured by
Durakool Inc. Long ago a repairman installed a magnetic switch as part of
a repair job and left us with a kiln that made a constant clicking noise
as the switch did it's work. I can only imagine how iritating 3 magnetic
switches might sound! I am wondering if anyone might point me to a source
(s) for replacement magnetic switches- maybe sonme that are relatively
quiet if such a thing exists. I have a couple mercury replacements left
and after they are gone I will probably have to switch over. I havent
checked with the kiln manufacturer yet though I will- wanted some input
here first.
Thanks- Sean Burns
Williamsburg, Ma.
Fredrick Paget on thu 2 nov 06
>Greetings,
> I recently received a notice from the State of Massachusetts that a
>campaign is underway in the public schools to eliminate all mercury except
>for some very limited laboratory instances. I run a electric kiln
>manufactured by Contemporary Kiln out of California and it has 3 mercury
>displacement switches in the electric box -those being manufactured by
>Durakool Inc. Long ago a repairman installed a magnetic switch as part of
>a repair job and left us with a kiln that made a constant clicking noise
>as the switch did it's work. I can only imagine how iritating 3 magnetic
>switches might sound! I am wondering if anyone might point me to a source
>(s) for replacement magnetic switches- maybe sonme that are relatively
>quiet if such a thing exists. I have a couple mercury replacements left
>and after they are gone I will probably have to switch over. I haven't
>checked with the kiln manufacturer yet though I will- wanted some input
>here first.
> Thanks- Sean Burns
> Williamsburg, Ma.
I can think of several ways tat it can be done. Perhaps the best
way is to use solid state relays. These can be had in modular form
and of large enough size to handle the current and voltage. They are
very quiet- perhaps a little hum.
Since they do not isolate the kiln completely when it is turned off a
magnetic switch is needed ahead of the group of solid state relays .
It is controlled by a separate output on the Bartlett controllers. It
only goes clack once each firing when you start out. This setup needs
to be designed by an engineer and is medium expensive. The folks at
the manufacturer could do it.
Fred Paget
--
Twin Dragon Studio
Mill Valley, CA, USA
fredrick@well.com
Charter Member Potters Council
Arnold Howard on fri 3 nov 06
From: "Sean Burns"
I have a couple mercury replacements left
> and after they are gone I will probably have to switch
> over.
----------
Sean, the mercury relays will probably last for many years.
Their service life is phenomenal. I wouldn't worry about
replacing them until they actually fail.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
Sean Burns on fri 3 nov 06
Thanks Fred-
While I can follow the logic of the setup it definately is
beyond my electronic abilitities- I will mention it to the manufacturer
to see how do-able it might be, and if so at what price.
Sean Burns
Williamsburg, Ma.
Sean Burns on fri 3 nov 06
From: Arnold Howard wrote:
The mercury relays will probably last for many years.
>Their service life is phenomenal. I wouldn't worry about
>replacing them until they actually fail.
>------------------------------------------------------------------
Arnold,
The mercury relays are definately long lasting and far outlast
the magnetic relay I mentioned. I do like to keep a couple on hand because
I am dead in the water with only one kiln and no replacement parts. I have
changed 5 of the suckers in the past 12 years or so( there are three
switches in the electric box)- the most recent being last year- so I am
very proactive rather than reactive- Sometimes it is impossible to get
money to fix anything in the middle of a school year.
I also owe you a belated thank you for the "Whats A Watt" booklet you
sent to me this summer- Thanks for the input and the booklet.
Sean Burns
Williamsburg, Ma.
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