Service manual

Refrigeration System Section 7
7-40
Part No. 80-1206-3
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 psi.
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 psi.
D. Change the vacuum pump oil.
E. Pull vacuum to 250 microns. Run the vacuum
pump for 1 hour.
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 2 psi, the filter-
drier should be adequate for complete cleanup.
B. If the pressure drop exceeds 2 psi, 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.
Important
Dry nitrogen is recommended for this procedure.
This will prevent CFC release.