Follett FZR Series Installation, Operation And Service Manual - Page 12
Browse online or download pdf Installation, Operation And Service Manual for Freezer Follett FZR Series. Follett FZR Series 20 pages. Undercounter freezer
Print Page
Refrigeration system
The FZR series -20 C (-4 F) freezer refrigeration system is designed to give many years of trouble-free service.
Except for routine cleaning and inspection of the air-cooled condenser and evaporator defrost, the refrigeration system
requires no service or maintenance. The system uses a thermostatic expansion valve and is critically charged. Access
fi ttings are provided for ease of service. However, the connection of refrigeration service hoses to the fi ttings will almost
invariably result in a signifi cant change in the system charge. This change can adversely affect the performance of
your freezer. 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.
Note: Do not charge the system by pressures.
Checking refrigeration system pressures
1.
Remove the rear access panel (Fig. 11).
2. Turn the power switch to the on position.
3. Following the instructions on page 6 verify that the temperature controller is
set to the original factory cut-in setting of -25 C (-13 F).
4. Allow the freezer to operate and stabilize at least 60 minutes, verifying the
cut-out temperature is being reached.
5. Connect refrigerant gauges to access fi ttings and measure air temperature
at condenser intake grille.
6. Verify correct pressures with the temperature chart below.
7.
Troubleshoot refrigeration system as needed.
Discharge and suction pressure table
Condenser Inlet Air Temperature
Discharge pressure (psi)
Suction pressure (psi)
Note: Do not attempt to obtain correct refrigeration pressures by adjusting the system charge.
Refrigeration system diagram
Low Psi
Vapor
EVAPORATOR/DEFROST UNIT
HIGH PRESSURE VAPOR
12
Service
70 F (21 C)
197
12
Low Psi
TXV
Liquid
HIGH PRESSURE LIQUID
80 F (27C)
90 F (32 C)
225
255
13
14
LOW SIDE
SERVICE PORT
HEAT EXCHANGE
DRYER
LOW PRESSURE LIQUID
Fig. 11
2
3
100 F (38 C)
285
15
COMPRESSOR
10oz. Charge
High Psi
Vapor
HIGH SIDE
SERVICE PORT
High Psi
Liquid
CONDENSING UNIT
LOW PRESSURE VAPOR
FZR Series 00939124R00