Refrigeration System
The Precision series refrigeration system is designed to give many years of trouble-free service. Except for
routine cleaning of the air-cooled condenser and related parts, the refrigeration system requires no service or
maintenance. The system uses a capillary tube and is critically charged. Access fittings are provided for ease
of service. However, the connection of refrigeration service hoses to the fittings will almost invariably result in a
significant change in the system charge. This change can adversely affect the performance of your refrigerator.
Therefore, Follett recommends that if hoses are ever connected to the refrigeration system for service, the
refrigerant should be recovered, the system evacuated, and recharged by weighing in the correct refrigerant
charge.
Checking Refrigeration System Pressures
1. Remove the rear access panel.
2. Turn the power switch to the ON position.
3. Verify that the temperature controller is set to the original factory cut-in setting.
4. Allow the refrigerator to operate and stabilize at least 30 minutes, verifying the cut-out temperature is
being reached.
5. If the compressor doesn't cycle after 20 minutes, the following checks must be completed before
checking refrigeration pressures:
§
condenser coil is clean and clear
§
condenser fan is running
§
evaporator coil is clean and clear
§
evaporator fan motor is running
§
compressor is running at normal amp draw
6. Connect refrigerant hoses to access fittings and measure air temperature at condenser intake grille.
7. Verify correct pressures with the temperature chart below.
8. Troubleshoot refrigeration system as needed.
REF4P, REF5P
Condenser inlet air temperature
70 F (21.1 C)
80 F (26.7 C)
90 F (32.2 C)
100 F (37.8 C)
Discharge pressure (psi)
113
134
158
181
Suction pressure (psi)
11.5
13
15
17
Note: Do not attempt to obtain correct refrigeration pressures by adjusting the system charge.
Refrigeration System Diagram
HIGH PRESSURE VAPOR
HIGH PRESSURE LIQUID
LOW PRESSURE LIQUID
LOW PRESSURE VAPOR
HIGH SIDE
SERVICE PORT
LOW SIDE
SERVICE PORT
FILTER-DRIER
COMPRESSOR
EVAPORATOR
CAPILLARY TUBE
CONDENSER
REF4P and REF5P Undercounter Refrigerators 15
REUC235
