Operating instructions

Chapter 7
Error Messages
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Error messages are accompanied by an alarm.
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Non-interrupting messages do not stop the
firing. Terminating error messages do.
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FTH, FTC, and LTdE error messages are
based upon the adjustable setting in the
Temperature Deviation (TEdE) option
(page 24).
Note: On controllers with pre-18D soft
-
ware, the HTdE error message is also based
on the TEdE option.
Non-Interrupting
Error Messages
Press to silencethe alarm.(Do notpress to
silence the alarm.) The error message will remain but the
kiln will continue firing. Even though the following error
messages appear, the kiln will continue its normal opera-
tion. The messages are only to alert you that the kiln could
not cool or heat as fast as you had programmed. But they
will not shut off the kiln or affect the firing in any way.
Definition of “Set Point”
The temperature that the controller is trying to reach, at
any given time, is called the set point. During heating or
cooling, the set point changes at the rate you programmed.
During a hold, the set point remains steady.
FTC / Failed to Cool
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During a cooling-down ramp, the programmed rate is
faster than the kiln can cool. The temperature is above
the set point temperature by more than the deviation
setting. (See Temperature Deviation, page 24.) Pro
-
gram a slower cooling rate.
Note: On controllers with 18D and later software:
Use Present Status to compare the actual rate of the
current Ramp-Hold segment with the rate you pro
-
grammed. (See page 7.)
FTH / Failed to Heat
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During a heating-up ramp, the programmed rate is
faster than the kiln can heat. The temperature is below
the set point temperature by more than the deviation
setting. (See Temperature Deviation, page 24.)
Program a slower rate. Or check for worn or burned out
elements, defective relays, low voltage and defective ther
-
mocouple.
Note: On controllers with 18D and later software:
Use Present Status to compare the actual rate of the
current Ramp-Hold segment with the rate you pro
-
grammed. (See page 7.)
LTdE / Low Temperature Deviation
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During a cooling-down ramp or a hold, the temperature
is below the set point temperature by more than the de
-
viation setting. (See Temperature Devia
-
tion, page 24.) Check for worn or burned
out elements, defective relays, low voltage
and defective thermocouple.
Note: During a firing, Present Status
shows the actual firing rate of the current
Ramp-Hold segment instead of the rate you
programmed. If you think your kiln is heat
-
ing or cooling too slowly, compare the rate
shown in Present Status with the rate you
programmed for that segment. This is an
-
other reason you should always keep a writ
-
ten record of your firing programs.(Pre-18D
software versions show the programmed
rate in Present Status rather than the actual rate. See
page25, SOFToption, to look upthe software version.)
PF/PowerFailure
alternating with normal display means the power
failed during firing. After power was restored, the firing re-
sumed.
TC with Lines / Multiple-Zone Kiln
Thermocouple Failure
The kiln will continue to fire as long as at least one ther-
mocouple is working. The lines following “TC” represent
the position inside the kiln of the thermocouple(s) that
failed.
Top line = top thermocouple
Middle line = middle thermocouple
Bottom line = bottom thermocouple
Top thermocouple failed
Middle thermocouple failed
Bottom thermocouple failed
Top and middle thermocouples failed
Top and bottom thermocouples failed
Top, bottom and middle thermocouples failed
On Sentry controllers with pre-18D software, “TC” is
followed by a number and a line. You can check the soft
-
ware version of your controller by using the SOFT Option.
See page 25.
Multiple-zonecontrollers with 18Dor earliersolftware:
TC 1¯ Top Thermocouple Failed
TC 2- Middle Thermocouple Failed
TC 3_ Bottom Thermocouple Failed
26 Cone-Fire / Ramp-Hold
If you keep get
-
ting error codes
such as FTH or
FTC, see Tem
-
perature Devia
-
tion on page 24.