Refrigerated Incubator
4-1
Thermo Scientific
Section 4
Service
Warning
Service should be performed only by qualified service personnel.
Exercise care as line voltage is present in the control compartment.
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If refrigeration service is required, after review of the Troubleshooting
Section, contact Technical Services.
In any communication with Thermo, include the model and serial
numbers from both nameplates.
Problems encountered with any constant temperature chamber will most
frequently be related to temperature control. Before proceeding with
detailed troubleshooting, be certain that the Low Limit and High Limit
controls are adjusted properly. If the limit controls are set too close or
beyond the operating temperature, the incubator may be consistently going
into alarm. This will result in erratic temperature control. First, the
symptoms and possible causes will be listed for quick reference. Solutions
will be suggested later.
Warning
Hazardous high voltage conditions exist inside the control panel.
unplug line cord and turn "off" line switch before removing the cover.
Only qualified electrical instrument personnel are authorized to perform
troubleshooting and/or servicing.
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Freeze-up or gradual drop in chamber temperature:
No air circulation in chamber; inoperative fan (see Solution 1)
Heater (see Solution 2)
Power Supply PCB Assembly (see Solution 3)
RTD Temperature Probe (see Solution 3, Step D and/or Solution 4).
Side walls are getting warm:
Depending on ambient temperature and the specific settings, the side
walls may get warm to the touch - up to 60°C (140°F) .
This is not a malfunction. This is normal due to the location of the con-
denser heat exchanger of the cooling system. Note that it has no impact
on the specified performance of the unit.
Troubleshooting
Symptoms and Possible
Causes
