Operating instructions

TCdE / Uneven Multiple-Zone
Temperatures
The zones of a multiple-zone kiln are firing unevenly.
Causes:
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A burned out element or relay
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The thermocouples and elements are improperly wired.
A thermocoupleis turning on the elements to the wrong
zone. For instance, if the top thermocouple turns on the
bottom elements, the kiln will fire out of balance. When
zones are out of balance by 180°F / 100°C, will
appear in the display.
Visually compare the wiring of the thermocouples, re
-
lays and elements in your kiln to the kiln’s wiring diagram.
Also, use the Element Test option shown on page 25.
TCL / Thermocouple Lag
The heatingrate is slower
than 9°F / 5°C per hour and
the kiln temperature is more
than 100°F / 56°C away from
the programmed tempera
-
ture. The TCL becomes in
-
active above 500°F/260°C.
Causes:
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On kilns that use a porta-
ble controller, the ther-
mocouple fell out of the
firing chamber.
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A bare spot on the ther-
mocouple lead wires has touched a grounded object in-
side the kiln switch box causing the thermocouple to
short out.
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will flash if you program a cooling segment tem
-
perature that is below room temperature. When
appears, press .
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Check for worn or burned out elements, defective re
-
lays, low voltage and defective thermocouple.
Note: The TCL alarm is available only on software
version 18D or later. You can check the software ver
-
sion of your controller by using the SOFT Option. See
page 25.
TCR / Thermocouple Leads Reversed
Check that the thermocouple lead wires are connected
to the correct terminals. See your wiring diagram.
Power Failures
The Sentry handles a power failure in two ways:
After a brief power failure, the controller contin
-
ues firing asbefore. It shows a normaltemperature
display alternating with .
After an extended power failure, or
will appear. The kiln will NOT resume fir
-
ing.
The kiln will remain turned off after a power failure un
-
der these conditions:
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The kiln will remain off if the temperature is below
212°F / 100°C when the power comes back on.
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The kiln will remain off if the temperature dropped
72°F / 40°C or more.
When the Sentry aborts a firing aftera power failure, the
display will show the following:
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or
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Total firing time before power failed
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Temperature at the time of power failure
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Current kiln temperature
To resume firing, press . The kiln will begin firing
again from its present temperature. For example, the kiln
reached 1000°F / 538°C when power failed. The tempera
-
ture is 800°F / 426°C when you turn the kiln back on. Firing
will resume from 800°F / 426°C. You need not cool the kiln
to room temperature before starting a ceramic firing over
unless you decide to use new witness cones.
When you resume firing by pressing , the control
-
ler begins firing in the first segment that has a higher target
temperature than the current kiln temperature. However,
if the power failed during a ramping down (cooling) seg-
ment, the controller will resume firing from the same cool-
ing segment.
Using Ceramic Shelf Cones After an
Extended Power Failure
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Fire the ware
again. It is okay to use the same partially fired witness
cones, even if they cooled back down to room tempera-
ture. So long as the cones did not heat to within
100°F/56°C of maturity, they can be used again.
I
Fire the ware
again. If the kiln shuts off within 100°F / 55°C of matu
-
rity, and the temperature drops 50°F / 28°C or more af
-
ter the kiln shuts off, do not depend on the witness
cones. Once they cool 50°F / 28°C after they have been
heated to within 100°F / 55°C of maturity, they will not
bend properly. This is because they form a hard shell.
28 Cone-Fire / Ramp-Hold
The warranty
does not cover
damage from
over-firing.
Please check the
kiln to make
sure it shuts off
at the proper
time.