Manitowoc Ice S1800 service manual Section Refrigeration System

Section 7 Refrigeration System

10.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.

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 .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 psi (35 kPa .35 bar).

D.Change the vacuum pump oil.

E.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.

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

12.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 (7 kPa,

.7 bar), the filter-drier should be adequate for complete cleanup.

B.If the pressure drop exceeds 1 psi (7 kPa, .7 bar), change the suction line filter-drier and the liquid line drier. Repeat until the pressure drop is acceptable.

13.Operate the ice machine for 48-72 hours. Then, remove the suction line drier and change the liquid line drier.

14.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.

•Water regulating valve

•High pressure cut-out control

•High side service valve

•Low side service valve

Important

This is a required in-warranty repair procedure.

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.

!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.

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%.

Part Number 80-1634-3 7-25