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Refrigeration System
REPLACING PRESSURE CONTROLS
WITHOUT REMOVING REFRIGERANT
CHARGE
11. Follow the normal evacuation procedure, except
replace the evacuation step with the following:
Important
Dry nitrogen is recommended for this procedure.
This will prevent CFC release.
This procedure reduces repair time and cost. Use it
when any of the following components require
replacement, and the refrigeration system is
operational and leak-free.
A. Pull vacuum to 1000 microns. Break the
vacuum with dry nitrogen and sweep the
system. Pressurize to a minimum of 5 psi.
• Water regulating valve (water-cooled only)
• High pressure cut-out control
B. Change the vacuum pump oil.
• High side service valve
C. Pull vacuum to 500 microns. Break the
vacuum with dry nitrogen and sweep the
system. Pressurize to a minimum of 5 psi.
• Low side service valve
Important
D. Change the vacuum pump oil.
This is a required in-warranty repair procedure.
E. Pull vacuum to 250 microns. Run the
vacuum pump for 1/2 hour on self-contained
models, 1 hour on remotes.
1. Disconnect power to the ice machine.
2. Follow all manufacturer’s instructions supplied
with the pinch-off tool. Position the pinch-off
tool around the tubing as far from the pressure
control as feasible. (See the figure on next
page.) Clamp down on the tubing until the
pinch-off is complete.
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 is no leak.
12. Charge the system with the proper refrigerant to
the nameplate charge.
WARNING
Do not unsolder a defective component. Cut it out
of the system. Do not remove the pinch-off tool
until the new component is securely in place.
13. 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 psi, the
filter-drier should be adequate for complete
cleanup.
3. Cut the tubing of the defective component with
a small tubing cutter.
4. Solder the replacement component in place.
Allow the solder joint to cool.
B. If the pressure drop exceeds 1 psi, change
the suction line filter-drier and the liquid
line drier. Repeat until the pressure drop is
acceptable.
5. Remove the pinch-off tool.
6. Re-round the tubing. Position the flattened
tubing in the proper hole in the pinch off tool.
Tighten the wingnuts until the block is tight and
the tubing is rounded. (See the drawing on next
page.)
14. Operate the ice machine for 48-72 hours. Then,
remove the suction line drier and change the
liquid line drier.
15. Follow normal evacuation procedures.
NOTE: The pressure controls will operate normally
once the tubing is re-rounded. Tubing may not re-
round 100%..