Operating instructions

Chapter 1
Basic Pointers
Two Firing Modes
The Sentry fires in two modes:
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, based onpyrometric cones (page
10). Quickly program a firing by selecting a cone num
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ber and firing speed.
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with custom firing rates and target tem
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peratures is for ceramists who want to design their own
firing schedules (page 14).
Ceramic kilns use both Cone-Fire and Ramp-Hold.
Heat treating, glass fusing, and enameling furnaces and
kilns come with Ramp-Hold only.
From display, press .If appears, you
have Cone-Fire mode.If the key does not respond,
you have Ramp-Hold mode only.
Press to bring the controller back to .
If you have Ramp-Hold only, skip pages 10 - 13.
Room Temperature and Humidity
It is okay to store the Sentry at sub-zero tem-
peratures. But before operating,raise the room
temperature to at least 32°F / 0°C.
Note: The Sentry will register sub-zero °F / °C
temperatures. However, 32°F / 0°C is the low-
est recommended operating temperature.
The circuit board is rated for 176°F / 80°C
maximum operating temperature. However,
the maximum recommended temperature is
158°F / 70°C, measured at the controller inside
the kiln switch box. To lower the temperature,
open windows and use a fan to blow air across
the kiln’s switch box louvers. (See page 24 to check circuit
board temperature.)
High humidity will not adversely affect the Sentry unless
water condenses on the circuit board. In this case, do not
fire the kiln until the moisture has evaporated from the
board.
Thunder Storms and Power Surges
Unplug the kiln when not in use, especially during thun
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der storms and in areas with frequent power surges. If the
kiln is part way through a firing when a storm begins, it may
be okay to continue the firing. When the kiln shuts off, dis
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connect the power.
CAUTION: When firing the kiln during a storm, do
not leave the kiln unattended!
Time and Temperature Display
Center Dot: Time
A center dot appears during
time display. It separates hours
from minutes (i.e. 1 hour, 30 min
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utes displays as 01.30). During
temperature display, the dot disappears.
Three-Light Display
The Sentry turns on the heat
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ing elements intermittently
through relays. Power output
lights appear in the right side of
the display when the Sentry sends
a signal to turn on the relays.
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When the Sentry sends a signal to
the relays, all three lights appear.
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The top light indicates power to
the top section of the kiln, the middle light power to the
middle section, and the bottom light power to the bot
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tom section. (Two-zone kilns: Ignore the center light.)
Note: Thoughpower output lights areon, mechanical
problems can prevent the relays from turning on.
Single Right-Hand Dot: °C
When temperature is dis-
played in °C, a dot appears in the
lower right. In °F display, itdisap-
pears. You can choose between
Fahrenheit and Celsius display. See page 22.
Operation Begins
from the IdLE Display
The controller displays
when you first apply power to the kiln. Operation begins
from . You can’t fire the kiln until appears.
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If you press during a firing, will appear. To
get back to , press .
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If the display shows an error message such as in
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stead of , see pages 26 - 28.
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(firing completed) appears at the end of a firing.
To make appear, press any key.
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If you do not touch the keys for one minute during pro
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gramming, the controller will go back to . The
controller will also discard the program you were enter
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ing and retain the previous program in memory.
CPLT Message: Firing Completed
When the firing has successfully completed, the Sentry
will shut off powerto the elements. Then four messages will
cycle one after the other:
(complete)
Firing time in hours and minutes
The temperature reached during the last segment
The current kiln temperature
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