Thermo Scientific Jewett CTF306 Blood Plasma Freezers
Installation and Operation
TROUBLESHOOTING SERVICE CHART
SYMPTOM
POSSIBLE CAUSE
POSSIBLE CORRECTIVE STEP
1. Excessively high discharge pressure.
1. See high discharge pressure symptom.
2. Low voltage to unit.
2. Determine reason and correct.
3. High voltage to unit.
3. Determine reason and correct.
4. Thermal overload protector defective.
4. Check current, Replace protector.
5. Run capacitor failure or wrong.
5. Replace run capacitor.
6. Motor electrical trouble.
6. Check motor for open windings, Short
circuit or burn out.
D
Compressor
starts and
runs, but
short cycles
on overload
protector.
7. Improper wiring causing additional
current to pass through overload protector.
7. Check wiring diagram. Check for added
fan motors, heaters, etc., connected to
wrong side of protector.
1. Differential set too close.
1. Widen differential.
2. High discharge pressure.
2. See high discharge pressure symptom.
E
Compressor
starts and
runs, but
short cycles
on
temperature
or pressure
controls.
3. Low discharge pressure.
1. See low discharge pressure symptom.
1. Shortage of refrigerant.
1. Leak check and repair.
2. Control contacts stuck or frozen.
2. Clean contacts or replace control.
3. Refrigerated air space has an excessive
load.
3. Determine reason and correct.
4. Dirty Condenser
4. Clean condenser.
5. Evaporator coil iced.
5. Defrost and check defrost circuit.
6. Restriction in refrigeration system.
6. Determine location and remove.
F
Compressor
runs long or
continuously.
7. Evaporator fan motors not running.
7. Determine reason and correct. Check
door switch.
1. Flooding of refrigerant into crankcase.
1. Check expansion device and refrigerant
charge.
2. Improper piping support.
2. Relocate tubing or add hangers.
3. Worn compressor.
3. Replace compressor.
4. Loose parts or mounting.
4. Find and tighten.
G
Compressor
noisy or
vibrating.
5. Condenser fan blade loose or impeded.
5. Check and repair.
1. Non-condensables in system.
1. Remove the non-condesables.
2. System overcharged with refrigerant.
2. Correct the charge.
3. Discharge shutoff valve partially closed. 3. Open valve.
4. Condenser fans not running.
4. Check electrical circuit.
H
High
Discharge
pressure.
5. Dirty condenser.
5. Clean.
1. Suction shutoff valve partially closed.
1. open valve.
2. Insufficient refrigerant in system.
2. Check for leaks. Repair and add charge.
I
Low
discharge
pressure.
3. Low suction pressure.
3. See low suction pressure symptom.
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