Programming instructions

4 Single Segment/Ramp-Hold
1) It fires at a controlled heating rate, or speed, mea
-
sured in degrees of temperature change per hour.
2) It fires to a target temperature.
3) It can hold the target temperature.
The controller fires in segments, or stages. A segment is
a given heating rate to a targettemperature.Shown above is
a segment with a target temperature of 1250° and a rate of
625°, with a hold of one hour.
Heating rate is figured in degrees per hour. The recom
-
mended heating rate for the material you are firing is usu
-
ally available from your supplier. It also varies depending
on the thickness of the material.
To figure how long a firing segment will take, subtract
the current temperature from the target temperature and
divide the resultant temperature by the heating rate. In the
diagramabove, the firing time is 1250° - 80° (room tempera-
ture) = 1170 ÷625 = 1.87 hours.
The controller can fire up to 8 segments per firing. One
segment is often all that is needed, though.
After the controller has finished firing the last segment,
it will turn off power to the elements.
Rate
Each segment must include a rate, which is degrees of
temperature change per hour.
Thekilnwillfireatfullpowerwhentherateis
1799°F/999°C. Full power displays as .
Note: To enter full power from , press the
key once.
pear, alternating with time left until the firing be
-
gins.
Power Failures
After a power failure, the controller will continue firing
provided that:
I
The kiln temperature is above 212°F/100°C when the
power comes back on.
I
The temperature dropped no more than 180°F/100°C
while the power was off.
Power Failure Messages
The power failed during firing, and temperature
dropped more than 180°F/100°C.
The power failed during firing, and kiln tempera
-
turewas below 212°F/100°C when the power came back on.
CPLT Message: Firing
Completed
When the firing has success
-
fully completed, the Sentry
Xpress will shut off power to
the elements. Then three mes-
sages will cycle one after the other:
(complete)
Firing time in hours and minutes
The current kiln temperature
Thunder Storms and
Power Surges
Unplug the kiln or disconnect the power when the kiln is
not in use, especially during thunder storms and in areas
with frequent power surges. If the kiln is part way through a
firing when a storm begins, it is probably okay to continue
the firing with close supervision. Do not leave the kiln unat
-
tended.
Theory of
Operation
The temperature you are firing to is called the target
temperature. After the controller reaches the target tem
-
perature, it can also hold that temperature.
The controller fires at a controlled heating rate. The rate
is figured in degrees per hour. If you selected a rate of 100°
per hour, it would take 10 hours for the kiln to reach 1000°.
Rate is similar to “miles per hour.”
In summary, the controller does three basic tasks: