Manitowoc QuietQube Series Technician's Handbook page 174

Dry nitrogen is recommended for this procedure. This
will prevent refrigerant release.
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 hour.
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,
0.07 bar), the filter-drier should be adequate for
complete cleanup.
B. If the pressure drop exceeds 1 psig (7 kPa,
0.07 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.
174

Important
Part Number: 000015431 Rev01 5/19