Controlled-Rate Freezer
Alarms | 35
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The Chamber temperature display will revert to normal
when the Chamber Thermocouple Failure alarm recovers.
Note:
Neither Warming mode nor a profile run may be
initiated while this alarm is present.
Figure 88. Chamber Thermocouple Failure
(Warning)
Sample Thermocouple Failure
If the sample thermocouple cannot be detected or reads
erroneous values (>75°C), an alarm will be triggered
according to the general alarm guidelines.
The Controlled-Rate Freezer will respond to the alarm in
different ways depending upon the current mode and
selected freezing profile.
Idle Mode
The Sample temperature display on the home screen shows
“…” when a Sample Thermocouple Failure alarm is active.
Figure 89. Sample Temperature Display (Home
Screen)
The Sample temperature display will revert to normal when
the Sample Thermocouple Failure alarm recovers.
Note:
Profile runs cannot be initiated while this alarm is
present. Warming mode, however, can still be initiated with a
sample probe failure alarm present.
Active Run (Non-Sample Probe Profile)
If the Sample probe fails during a freezing profile which does
not reference the Sample probe, the freezing profile will not
terminate. An alarm will still be generated according to the
general alarm guidelines.
Active Run (Sample Probe Profile)
If the Sample probe fails during a freezing profile which
references the Sample probe, the freezing profile will
terminate. Once the failure is detected, a dialog will prompt
the user to acknowledge the alarm. Upon acknowledgment,
the Controlled-Rate Freezer will return to the home screen
and enter Idle mode. A RUN file will be written as if the run
was canceled early.
Heater Malfunction
If the heater is energized continuously (no active temperature
control) for 60 minutes or longer, the Controlled-Rate Freezer
will generate a Heater Malfunction alarm according to the
general alarm guidelines.
This alarm is considered a non-clearing alarm and will
terminate an active run. Once the failure is detected, a dialog
will prompt the user to acknowledge the alarm. Upon
acknowledgment, the Controlled-Rate Freezer will return to
the Home screen and enter Idle mode. A RUN file will be
written as if the run was canceled early.
Once the Controlled-Rate Freezer returns to Idle mode and
the heater is de-energized, the alarm will automatically clear.
LN
2
Alarm
If one or both LN
2
valves are energized continuously (no
active temperature control) for 60 minutes or longer, the
Controlled-Rate Freezer will generate an LN
2
Malfunction
alarm according to the general alarm guidelines.
This alarm is considered a non-clearing alarm and will
terminate an active run. Once the failure is detected, a dialog
will prompt the user to acknowledge the alarm. Upon
acknowledgment, the Controlled-Rate Freezer will return to
the Home screen and enter Idle mode. A RUN file will be
written as if the run was canceled early.
WARNING:
If this alarm persists or the heater
ceases functioning after an occurrence of this
alarm, contact a service representative.
