Operation; Temperature Control; Automatic Defrost; Controller Operation - Follett REF1 Installation, Operation And Service Manual

Operation

The temperature control board and probe indicate when the refrigeration system is required to turn on and off.
The refrigeration system removes heat from the cabinet interior and rejects it to the surrounding room air.
When the cabinet interior temperature rises above the controller cut-in temperature, the controller turns the
refrigeration system on. The controller energizes the evaporator fan and solid-state control relay which energizes
the condensing unit. The compressor uses a current-style starting relay and a starting capacitor to start the
compressor motor.
When the cabinet interior temperature falls below the controller cut-out temperature, the controller turns the
refrigeration system off. The controller contacts reopen, which de-energizes the evaporator fan motor and solid-
state control relay which de-energizes the condensing unit (compressor and condenser fan motor).
Any accumulated frost on the evaporator coils melts during the off cycle. The condensate drains out of the unit
to the condensate tray to the left of the condensing unit. The heat from the condensing unit evaporates any
condensate in the drain pan.

Temperature Control

The temperature control system is preset by the factory to maintain a cabinet temperature of 3.3 – 5.5 C
(38 – 42 F). If desired, the set-point temperature can be raised as high as 10 C (50 F) by following the
instructions in Controller Operation for changing the temperature set point. The 2.2 C differential will be
maintained regardless of the controller set point.

Automatic Defrost

REF Series refrigerators do not require manual defrosting. The unit defrosts automatically when the condensing
unit is in the OFF cycle.
Any accumulated frost on the evaporator coil melts during the OFF cycle. The condensate drains to a plastic
drain pan mounted below the condensing unit. The heat from the condensing unit evaporates any condensate in
the drain pan.

Controller Operation

In normal operation, the controller displays product temperature in degrees C (default) or user-selected degrees F.
The controller is pre-programmed with a 4.4 C (40 F) set point. COMP displays when the compressor is running.
If this set point does not meet your specific application needs, instructions for changing the set point are found
below.
Note: Follett presets its refrigeration system to hold product temperature at approximately 4.4 C (40 F). If you are
using this in a food service application, and installing in accordance with NSF, you must set the control
set-point to 3.3 C (38 F). This will deliver a product temperature below the 4.4 C (40 F) NSF requirement.

Controller Display

The controller display will show the product/bottle temperature in degrees C or degrees F as selected by the user
except when the unit is in an alarm.
The controller has system indicators above the temperature display to let you know when: the compressor is
energized (COMP), the evaporator fan is energized (FAN) or the unit is in defrost (DEF).
REF1/REF2 Compact Refrigerators 13