search  current discussion  categories  kilns & firing - elements 

element life and slow cooling: now relays

updated tue 16 nov 10

 

David Martin Hershey on fri 12 nov 10


Hi Bill,

Interesting!

After I started experiencing relay failure,
I intuitively added a small fan pointed at
the vents on my attached controller box
to see if keeping the controls cooler
would help extend their life.

I've had relays fail in both the open and
closed position. They look black & burnt
through the plastic housing.

This may be somewhat normal because
of the arcing when the relay opens & closes?

My newest Skutt relays are in metal housings now.

Are any of your crystalline group using
mercury relays? If so, how are they holding up?

My guess is that to keep costs down,
kiln manufacturers are using relays that
are not really engineered for long term
serious "normal" use in an electric kiln.

Perhaps Arnold can enlighten us on that subject.

Best, DMH

David Martin Hershey
DMH Studio + Design
2629 Manhattan Ave #137
Hermosa Beach CA USA
90254-2447 424.241.3809
http://www.dmhstudio.com/
http://www.obamacardgold.com
http://www.winetastingtrolley.com/


On 11/12/2010 5:56 AM, William & Susan Schran User wrote:
> On a crystalline glaze forum there has been lots of discussion about
> SSR's,
>

Arnold Howard on mon 15 nov 10


From: "David Martin Hershey"
> Are any of your crystalline group using
> mercury relays? If so, how are they holding up?
>
> My guess is that to keep costs down,
> kiln manufacturers are using relays that
> are not really engineered for long term
> serious "normal" use in an electric kiln.

The standard mechanical relay used in most kiln brands is
the 30 amp P&B. Much better than the mechanical relay is the
mercury type, which is optional on most Paragon kilns and
standard on the Paragon Dragons and Vikings.

Glass fusing kilns are far harder on relays than are the
ceramic kilns. This is because thick glass requires very
long annealing times (slow cooling). In some cases, a kiln
will anneal the glass for several days. Mercury relays have
performed well in that environment.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com