Manitowoc Ice FLAKE/CHIPLET QF0400 User Manual

Page 143

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Section 7

Refrigeration System

Part No. 80-1214-3

7-21

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 500 microns. Run the vacuum

pump for 1/2 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 filter/drier and change the
liquid line drier. QF2300- Replace with a new suction
filter.

13. Follow normal evacuation procedures.

REPLACING PRESSURE CONTROLS WITHOUT
REMOVING REFRIGERANT CHARGE

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.

High pressure cut-out control

High side access valve

Low side access valve

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.

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.

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.)

NOTE: The pressure controls will operate normally once
the tubing is re-rounded. Tubing may not re-round 100%.

Important

Dry nitrogen is recommended for this procedure.
This will prevent CFC release.

Important

This is a required in-warranty repair procedure.

!

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.

Revised 8/2003

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