Skutt KilnMaster Kilns Manufactured between 2000 and 2006 - Manual (Page 39)

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A PPENDIX 1
KilnMaster
Controller
Specifications and
Capabilities
The kiln-mounted controller on Skutt
KM-series automatic kilns and Wall-
mount KilnMaster controller have the
same specifications.
Thermocouple: Type K
Electronic cold junction compensation
Power supply: 24 volt center tap trans-
former
Output: Drives up to 450 mA at 12
volts
Fuse: 1/2 Amp, 250 Volt
Control Panel: Sealed Touch Pad,
washable
Control capabilities:
Delay Firing Start: up to 99 hours and
99 minutes
Cone Fire Mode: Entry by cone num-
ber, 3 firing speeds, Cone 022 to
Cone 10.
Ramp/Hold Mode: Entry by tempera-
ture, create programs from 1 to 8
segments. Each segment can specify
a rate of heating or cooling to a spec-
ified temperature with an optional
hold, to maximum temperature of
2,400˚ F. Stores up to six complete
programs.
Electronic Cone Table: Converts cone
numbers to temperature.
Program Review: Review program
and current segment during firing.
Temperature Alarm: Adjustable to
desired temperature.
Safety features: Power Failure
Detection, Thermocouple Failure
Detection, Microprocessor Fault
Detection.
Designed and manufactured in the
USA.
A PPENDIX 2
Cone Chart
and Heat Work
Cone deformation
Each cone has a number which corre-
sponds to a heating rate/temperature
combination producing a cone defor-
mation. At the beginning of the firing
the cone is standing at an 8˚ angle. A
perfectly fired cone will be bent to a
90˚ angle. More than a 90˚ angle is
overfired, less than 90˚ is underfired.
How a cone works.
• The maturing temperature or bend-
ing point of a cone is determined by
different chemical compounds which
are formulated to relate to heat work
in clays and glazes.
• Time and temperature are key fac-
tors in the way a cone operates. Here
are some points to consider:
1. Firing clay takes varying amounts of
time to be “done”. Thick walled
pieces take more time to cure to the
center than thin walled-cast pieces,
just like a 20 lbs turkey takes longer
to cook than a 10 lbs one.
2. Cones continue to drop after the fir-
ing is complete. A cone held at a
temperature for a long time will con-
tinue to bend even if the pro-
grammed temperature is lower than
the cone number. For example, if the
end firing temperature is slightly
short of maturity and put on hold
for a long time, the cone will eventu-
ally bend to full maturity.
3. Cone deformation depends on heat-
ing rate and the final temperature.
The chart on the next page helps
define this principle. It illustrates the
different temperatures a cone will
bend depending on the heating rate
per hour. For example, heating at
18˚/hr, the cone will deform at
1890˚; heating at 108˚/hr, the cone
will deform at 1944˚, at 175˚/hr, the
cone will deform at 1954˚.