Vollrath Stoelting F231, Service Manual, Page: 40 / 63

Service Manual #513659 32 Model F231
C. CHECK VALVE
The machine has 3 magnetic check valves (Refer to
Figure 5-6). Each valve is positioned in the suction line
and prevents back
fl ow of refrigerant into the evapora-
tor. If there is reversed fl ow, the product in the freezing
cylinder softens and liquid refrigerant can fl ood into the
compressor on startup.
If a check valve needs to be replaced, use a heat sink (wet
cloth) when installing the new valve to prevent damage.
D. HIGH PRESSURE CUTOUT
The high pressure cutout stops the compressor if the
discharge pressure reaches the cutout, 445 psig for the
freezing cylinders. It is an automatic reset when the pres-
sure drops below 350 psig.
HIGH PRESSURE CUTOUT TEST
A. Connect a gauge to the Schrader valve on the
discharge line.
B. Disconnect cooling:
In a water-cooled machine, shut off the water
supply.
In an air-cooled machine, shut off the fan motor
in the IntelliTec2™ control. Refer to Section 4.6
for details.
C. High pressure cutout should trip when pressure
reaches 445 psig ±9.
HIGH PRESSURE CUTOUT REMOVAL
A. Remove the left side panel.
B. Recover refrigerant charge per instructions in
Section 5.2.
C. Leave the suction and discharge ports open to
prevent pressure buildup during removal.
D. Unsweat capillary tube from suction line.
E. Disconnect terminals from high pressure cutout.
HIGH PRESSURE CUTOUT REPLACEMENT
A. With the suction and discharge ports open, braze
the capillary tube to the discharge line.
C. Replace the drier per the instructions in Section
5.9.
D. Braze bulb into place on suction line.
E. Evacuate the system per the instructions in Section
5.2.
F. Recharge the system per the instructions in
Section 5.3.
G. Connect the terminals to the high pressure cutout.
H. Attach the high pressure cutout using the two
screws with star washers.
E. HOT GAS BYPASS
The hot gas bypass valve is installed parallel to the com-
pressor and helps to regulate the compressor temperature
(Refer to Figure 5-8). When the cab evaporator is the only
part of the system requiring refrigerant, the bypass valve
will allow discharge gas to bypass into the suction line to
prevent liquid refrigerant from entering the compressor.
Figure 5-8 Hot Gas Bypass
Figure 5-7 High Pressure Cutout
Figure 5-6 Check Valve