System Operation - Viking VUWC244DRSS Service Manual

2.2

System Operation

The dual zone wine cellar is designed with the intent of storing and chilling of wines. It is not classified
as a refrigerator and should not be utilized as such.
The dual zone wine cellar has two independent, temperature controlled zones. The temperature range for
each zone has an adjustable set-point range of 45˚F to 65˚F. Ideally these units should be set to operate
with a warmer upper zone for red wines (55˚F) while maintaining the lower zone at a colder temperature
for white wines (45˚F).
The temperature shown on the user interface is displayed as "real time" temperature for each zone. This
is unlike competitive models. It is important that the customer realizes that during normal operation of
the wine cellar, the display will show slight variations. This is the result of temperatures monitored dur-
ing on/off cycles, calls for heat, and defrosts periods.
The evaporator is located behind the evaporator cover located on the back wall of the cabinet interior. A
sealed divider separates the upper and lower compartments. Each zone has an independent thermistor,
compartment fan, and heater / fan assembly.
The dual zone wine cellar utilizes a single refrigeration system.
Temperature control for each zone is achieved by tempering the air in each compartment. This is
achieved by cycling the compressor with compartment fans or the heater / fan assembly at intervals
when needed. The thermistor of each compartment monitors the need for either a call for cooling or the
call for heat. The signal is then sent to the User Interface board on the control panel.
When a call for heat is monitored, the compressor, condenser fan, and compartment fans will all be dis-
abled. A 10 minute delay will occur before a call for heating can be initiated in the same compartment,
unless the set-point for that compartment has been changed. During a call for heat cycle, the compart-
ment fan is disabled during a simultaneous call for cooling in the other compartment
A call for heating will only occur if a set-point is set at 49˚F or above. A call for heating cycle will be
terminated if the set-point is changed to a setting less then 49˚F.
2.3 Defrost
The dual zone wine cellar does not incorporate either an electric heater or hot gas method for defrost.
Depending on the software version (See following page), defrost is achieved by utilizing additional com-
pressor off time at the conclusion of a predetermined, accumulated run time period. These parameters
have been programmed into the User Interface board and can not be changed or re-programmed.
2010 - Viking Preferred Service
9
SMR-0005