8
Operation
The temperature controller 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 reaches 2 C (4 F) above the controller set point, the probe signals the controller to turn
the refrigeration system on. The normally-open controller contacts 4 and 5 close and energize the evaporator and
condenser fan motors, compressor and door heater. The snowfl ake and fan LED's on the controller will come on to
indicate the refrigeration system is on. The compressor uses a current-style starting relay and a starting capacitor to
start the compressor motor.
When the cabinet interior temperature falls to the set point, the probe signals the controller to turn the refrigeration
system off. The controller contact 5 reopens, which de-energizes the condenser fan motor and the compressor. The
snowfl ake LED will go out, the fan LED will remain on.
Any accumulated frost on the evaporator coils melts during the defrost cycle. Freezer products will remain at or
below -20 C (-4 F) during the defrost cycle. The condensate drains to a drain pan mounted along 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 -33 C (-27 F). If
desired, the cut-out temperature can be raised as high as -25 C (-13 F) by following the instructions on page 6
for changing the temperature set point. The 2 C cut-out differential will be maintained regardless of the controller
set point.
Defrosting
The FZR5-PL undercounter freezer controls frost accumulation on the evaporator through automatic timed defrost
cycles. The defrost cycle is initiated by the temperature controller every 4 hours. Contacts 4 and 5 on the controller
open and the refrigeration system is turned off. Contact 2 is closed and the defrost heater is energized. The melting
snowfl ake LED on the controller will come on, and the temperature display will read: “dEF” to indicate the freezer is
in the defrost cycle.
The heater warms the evaporator coil and drain pan to melt the frost and drain the water to the condensate pan.
The temperature controller monitors evaporator temperature using a probe embedded in the coil. The controller
terminates the defrost cycle when the evaporator temperature reaches 5 C (41 F) or after 25 minutes of defrost
time, whichever occurs fi rst. As the defrost cycle terminates, the controller de-energizes the heater and restarts
the compressor and condenser fan. The snowfl ake LED on the controller will come on to indicate the refrigeration
system is running.
There is a 10 minute delay before the evaporator fan motor is re-energized. The fan LED on the controller will
come on to indicate the fan is running and the temperature display resumes displaying cabinet temperature. A
defrost cycle can be initiated manually at any time by depressing and holding the melting snowfl ake button for
approximately three seconds. As a safety feature, a temperature safety switch mounted on the evaporator will turn
off the defrost heater if the temperature of the evaporator r27 C (+80 F) regardless of controller operation.
Cleaning
Interior – Using a sponge or soft cloth, clean unit with a non-abrasive, non-chlorinated, all-purpose detergent.
Exterior – Wipe exterior with a soft cloth in the direction of grain as needed. Stainless steel polish may be used to
enhance the fi nish of the unit.
Use only non-chlorine-based cleaners. Cleaners containing chlorine can cause staining and pitting of the
stainless steel.
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Summary of Contents for C45184
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