Thermo Scientific Jewett CTF306 Installation And Operation Manual page 12

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