3-2
Isotemp Basic
Fisher Scientific
Section 3
Alarms
The "high stage system failure" condition is created when the high stage
compressor and fans run for 30 minutes and are not capable of cooling the
interstage heat exchanger to the proper temperature. Under this condition,
the high stage compressor and fans turn off after 30 minutes and an
audible and visual alarm occur. The audible alarm can be silenced and will
ringback every 15 minutes.
The microprocessor in Isotemp Basic freezers continually scans all probes
including the control probe, heat exchanger probe and condenser probe to
ensure that they are operating properly. Should an error be detected, the
"Probe Failure" alarm will occur as shown in the table above. If an error is
detected with the control probe, the high and low stage compressors will
run continuously. As a result, the cabinet temperature will decrease until it
reaches the lowest temperature that the refrigeration system can maintain.
If an error is detected with the heat exchanger probe, the freezer will cycle
properly at its temperature set point using a 5 minute step start between
the high and low stage compressors. If an error is detected with the
condenser probe, there is no impact on the performance of the freezer;
however, the hot condenser alarm may also occur. Contact the Technical
Services department or your local distributor.
High Stage System
Failure
Probe Failure Alarm
Summary of Contents for Isotemp Basic -86C
Page 17: ......
Page 29: ......
Page 41: ......
Page 47: ...A 4 Isotemp Basic Thermo Scientific ...
Page 48: ...Fisher Scientific 300 Industry Drive Pittsburgh PA 15275 USA www fishersci com ...