Welbilt FB081TF, Service Manual

Page: 82 / 96

82 Part Number REV00 04/08/2020
Component Check Procedures Section 7
CLEANUP PROCEDURE
Mild System Contamination
1. Replace any failed components.
2. If the compressor is good, change the oil.
3. Replace the liquid line drier.
Important
Dry nitrogen is recommended for this procedure.
This will prevent release of refrigerants.
4. Follow the normal evacuation procedure, except
replace the evacuation step with the following:
A. Pull vacuum to 1000 microns. Break the vacuum
with dry nitrogen and sweep the system. Pressurize
to a minimum of 5 psig (35 kPa,.35 bar).
B. Pull vacuum to 500 microns. Break the vacuum
with dry nitrogen and sweep the system. Pressurize
to a minimum of 5 psig (35 kPa,.35 bar).
C. Change the vacuum pump oil.
D. Pull vacuum to 500 microns. Run the vacuum
pump for 1/2 hour on self-contained models,
1 hour on remotes.
NOTE: You may perform a standing vacuum test to make a
preliminary leak check. You should use an electronic leak
detector after system charging to be sure there are no leaks.
5. Charge the system with the proper refrigerant to the
nameplate charge.
6. Operate the ice machine.
Severe System Contamination
1. Remove the refrigerant charge.
2. Remove the compressor and inspect the refrigeration
lines. If burnout deposits are found, install a new TXV.
3. Wipe away any burnout deposits from suction and
discharge lines at compressor.
4. Sweep through the open system with dry nitrogen.
5. Install a new compressor and new start components.
6. Install a suction line filter-drier with acid and moisture
removal capability. Place the filter drier as close to the
compressor as possible.
7. Install an access valve at the inlet of the suction line
drier.
8. Install a new liquid line drier.
9. Follow the normal evacuation procedure, except
replace the evacuation step with the following:
A. Pull vacuum to 1000 microns. Break the vacuum
with dry nitrogen and sweep the system. Pressurize
to a minimum of 5 psig (35 kPa,.35 bar).
B. Change the vacuum pump oil.
C. Pull vacuum to 500 microns. Break the vacuum
with dry nitrogen and sweep the system. Pressurize
to a minimum of 5 psig (35 kPa,.35 bar).
D. Change the vacuum pump oil.
E. Pull vacuum to 500 microns. Run the vacuum
pump for 1/2 hour on self-contained models, 1
hour on remotes.
NOTE: You may perform a standing vacuum test to make a
preliminary leak check. You should use an electronic leak
detector after system charging to be sure there are no leaks.
10. Charge the system with the proper refrigerant to the
nameplate charge.
11. Operate the ice machine for one hour. Then, check the
pressure drop across the suction line filter-drier.
A. If the pressure drop is less than 1 psig (7 kPa,.7 bar),
the filter-drier should be adequate for complete
cleanup.
B. If the pressure drop exceeds 1 psig (7 kPa,.7 bar),
change the suction line filter-drier and the
liquid line drier. Repeat until the pressure drop is
acceptable.
12. Operate the ice machine for 48-72 hours. Then remove
the suction line drier and change the liquid line drier.
13. Follow normal evacuation procedures.