Thermo Scientific 3881, Operating And Maintenance Manual

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5-2 7033881 Blood Bank Thermo Scientific
Section 5
Troubleshooting
Symptom Possible Cause/Possible Fix
Chamber not being refrigerated or refrigeration
is insufficient to provide stable temperature at
4°C; both compressor and condenser fan are
operating intermittently. Circulation fan is inoperative.
Refrigeration system temperature controller
needs adjusting or defective.
Ice on cooling coil.
Chamber not being refrigerated or refrigeration
is insufficient to provide stable temperature of
4°C; compressor and condenser fan are oper-
ating continuously. Insufficient amount of refrigerant, (refrigerant
leak). Repair, evacuate and recharge. See
charge label for type and amount.
Compressor starting relay is defective.
Defective compressor.
Defective temperature control.
Chamber not being refrigerated; compressor is
warm (indicating it is receiving power) but not
operating; condenser fan is operating Compressor starting capacitor is defective.
Compressor starting relay is defective.
Defective compressor.
Ice build-up on cooling coil. Defrost drain line is blocked.
Refrigeration system temperature controller is
defective.
Chamber temperature is not stable; tempera-
ture recovery time is slow when no product is
in the chamber. Defective air circulation fan.
Refrigeration system temperature controller is
defective.
Insufficient refrigerant (leak).
Defective compressor.
Compressor starting relay is defective.
Insufficient voltage.
Dirty condenser.
Insufficient ventilation at top of cabinet.