Refrigeration System

Section 7

 

 

Mild System Contamination Cleanup Procedure

1.Replace any failed components.

2.If the compressor is good, change the oil.

3.Replace the liquid line drier.

NOTE: If the contamination is from moisture, use heat lamps during evacuation. Position them at the compressor, condenser and evaporator prior to evacuation. Do not position heat lamps too close to plastic components, or they may melt or warp.

Important

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

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 psi (35 kPa).

B.Pull vacuum to 500 microns. Break the vacuum with dry nitrogen and sweep the system. Pressurize to a minimum of 5 psi (35 kPa).

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 is no leak.

5.Charge the system with the proper refrigerant to the nameplate charge.

6.Operate the ice machine.

Severe System Contamination Cleanup Procedure

1.Remove the refrigerant charge.

2.Remove the compressor.

3.Disassemble the harvest solenoid valve. If burnout deposits are found inside the valve, install a new harvest valve, and replace manifold strainer, TXV and harvest pressure regulating valve.

4.Wipe away any burnout deposits from suction and discharge lines at compressor.

5.Sweep through the open system with dry nitrogen.

Important

Refrigerant sweeps are not recommended, as they release CFC’s into the atmosphere.

6.Install a new compressor and new start components.

7.Install a suction line filter-drier with acid and moisture removal capability (P/N 89-3028-3). Place the filter drier as close to the compressor as possible.

8.Install an access valve at the inlet of the suction line drier.

9.Install a new liquid line drier.

Continued on next page …

7-24

Part Number 80-1634-3

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Manitowoc Ice S1800 Mild System Contamination Cleanup Procedure, Severe System Contamination Cleanup Procedure