14
FZR Undercounter Freezer
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 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 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. 14).
2. Turn the power switch to the on position.
3. Following the instructions on
page 7,
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 fittings and measure air
temperature at condenser intake grille.
6. Verify correct pressures with the temperature chart below.
7. Troubleshoot refrigeration system as needed.
Fig. 14
208
264
Prod
uct
Modu
le No
.
Serv
ice No
.
Ea
sto
n P
enn
syl
van
ia
MO
TOR C
OMPRES
SO
R TH
ER
MA
LLY PR
OTE
CTED
DESIGN
PRES
SUR
E HI
GH
SID
E
MIN.
BR
AN
CH
CI
RC
UIT
AMP
AC
ITY
MA
X. B
RA
NC
H C
IRC
UIT
FU
SE
SIZ
E
SING
LE
PH
AS
E
LO
W SI
DE
L
TH
E U
SA
MA
DE
IN
OZ
PSI
G
R
C
NS
F
UL
PA
RT
NO
HZ
CH
AR
GE
AMP
S
R
AMP
S
U
VO
LTS
CORPORA
TIO
N
SE
RIAL NO
MODEL
FU
LL
LO
AD
AMPS
REFR
IGERAN
T
1
2
3
Discharge and suction pressure table
Condenser Inlet Air Temperature
70 F (21 C)
80 F (27 C)
90 F (32 C)
100 F (38 C)
Discharge pressure (psi)
197
225
255
285
Suction pressure (psi)
12
13
14
15
Note: Do not attempt to obtain correct refrigeration pressures by adjusting the system charge.
Refrigeration System Diagram
DRYER
HIGH PRESSURE VAPOR
LOW PRESSURE VAPOR
HIGH PRESSURE LIQUID
LOW PRESSURE LIQUID
COMPRESSOR
FA
N
10oz. Charge
High Psi
Liquid
Low Psi
Liquid
High Psi
Vapor
Low Psi
Vapor
HEAT EXCHANGE
EV
APORA
TOR
FA
N
EVAPORATOR/DEFROST UNIT
CONDENSING UNIT
DEF
R
O
S
T
HEA
TE
R
EV
APORA
TO
R
TXV
LOW SIDE
SERVICE PORT
HIGH SIDE
SERVICE PORT
