Thermo Scientific Jewett CTF306 Blood Plasma Freezers
Installation and Operation
TROUBLESHOOTING SERVICE CHART
SYMPTOM
POSSIBLE CAUSE
POSSIBLE CORRECTIVE STEP
1. Line disconnect switch open.
1. Close disconnect switch
2. Fuse blown or breaker tripped.
2. Check electrical circuits and motor
windings for shorts or grounds. Investigate
for possible overloading. Replace fuse or
reset breaker after fault is corrected.
3. Thermal overload tripped.
3. Overloads are automatically reset. Check
unit closely when compressor comes back on
line.
4. No cooling required
4. None. Wait until control calls for cooling.
5. Control contacts stuck in open position. 5. Replace control.
6. Loose wiring.
6. Check all wiring junctions, tighten all
terminal screws.
7. Improper wiring
7. Check wiring against diagram.
8. Liquid line solenoid valve will not open. 8. Repair or replace solenoid coil
9. Motor electrical trouble.
9. Check motor for open windings, Short
circuit or burn out.
A
Compressor
will not start,
no hum
10. Liquid line solenoid will not open.
10. Repair or replace coil.
1. Low voltage to unit.
1. Determine reason and correct.
2. Start capacitor failure or wrong.
2. Replace start capacitor.
3. Run capacitor failure or wrong.
3. Replace run capacitor.
4. Start relay failure or wrong.
4. Replace start relay.
5. Motor electrical trouble.
5. Check motor for open windings, Short
circuit or burn out.
6. Internal mechanical trouble in
compressor.
6. Replace compressor.
7. Improper wiring
7. Check wiring against diagram.
B
Compressor
will not start,
hums but
trips on
thermal
overload.
8. Excessively high discharge pressure.
8. See high discharge pressure symptom.
1. Low voltage to unit.
1. Determine reason and correct.
2. Run capacitor failure or wrong.
2. Replace run capacitor.
3. Start capacitor failure or wrong.
3. Replace start capacitor.
4. Start relay failure or wrong.
4. Replace start relay.
5. Motor electrical trouble.
5. Check motor for open windings, Short
circuit or burn out.
6. Internal mechanical trouble in
compressor.
6. Replace compressor.
7. Improper wiring.
7. Check wiring against diagram.
C
Compressor
starts, but
does not
switch off of
start winding.
8. Excessively high discharge pressure.
8. See high discharge pressure symptom.
10
