Appendix
Thermo Scientific XBF40-MD Series Blast Freezers
Installation, Operation and Service Manual
35
Unit runs but little or no
refrigeration.
Run times are getting longer.
1. Loss of refrigerant.
2. Compressor will not pump.
3. Inoperative condenser fan.
4. Dirty insufficient air flow
5. High room temperature.
6. Refrigerant leak.
7. Condenser fan blade is loose.
8. Excessive ice on or in evaporator
9. Improper TXV settings
1. Check for the leak, repair, evacuate
and recharge.
2. Install low-side gauge. If running
pressure is no lower than starting
pressure, replace compressor,
evacuate and recharge.
3. Check for fan blade obstruction.
Replace fan motor if necessary.
4. Remove/Clean condenser filter;
ensure cabinet has a minimum of 6’
clearance all around it. Check for
fan blade obstruction. Replace fan
motor if defective.
5. Ensure room temperature is
< 32.2°C (90°F).
6. See Leak Check and Charging
procedures.
7. Tighten fan blade.
8. Check defrosts settings on the
controller. Defrosting required of
the evaporator.
9. Contact Service Support
Displayed temperature does not
match freezer temperature.
1. Needs calibration.
2. Defective sensor.
1. Recalibrate per specified procedure.
2. Replace Sensor
Table 2: Troubleshooting Procedures
SYMPTOM
POSSIBLE CAUSE
TEST AND CORRECTION