Viking VCSB360 Service manual

VCSB360 / 420 / 480
VIKING RANGE CORPORATION, P.O. DRAWER 956, GREENWOOD,MS 38930 USA

TABLE OF CONTENTS
TOOLS NEEDED FOR REPAIRS..................................................................................... 3
COMPONENT LOCATION
Theory of Operation........................................................................................................ 4-12
COMPONENTS ACCESS AND REPAIR
Components in the Refrigerator Section........................................................................ 13
1. Electronic Control Board................................................................ 13
2. Light Switch........................................................................................ 14
3. Motorized Air Door........................................................................... 15
4. Temperature Sensor (Thermistor)................................................... 15
5. Meat Locker Control......................................................................... 16
Components in the Freezer Compartment
1. Removing Freezer Thermostat......................................................... 17
2. Removing Light Switch..................................................................... 18
3. Removing the Evaporator Fan Motor............................................. 19
4. Removing the Bi-metal...................................................................... 20
5. Removing the Defrost Heater............................................................ 21
6. Installing a New Defrost Heater....................................................... 22
Components on Top of the Unit...................................................................................... 23
1. The Power On / Off Switch............................................................... 24
2. Removing the Defrost Timer............................................................. 25
3. Removing the Run Capacitor........................................................... 25
4. The Condenser Fan Motor................................................................ 26
5. The Water Valve................................................................................ 27
Door Assemblies
Replacing the Door Gaskets..................................................................... 28
TROUBLE SHOOTING AND DIAGNOSIS................................................................................ 29--40
R134a REFRIGERANT SERVICE INFORMATION............................................................ 41
MODULAR ICE MAKER SERVICE SHEET............................................................................ 42
WIRING DIAGRAMS AND LINE CIRCUITS........................................................................... 43--60
APPENDIX:
Refrigerator Installation Cutout ................................................................................... 61
Adjust Door Swing........................................................................................................... 62
Level Refrigerator............................................................................................................ 62
Installing Custom Side Panels........................................................................................ 63
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VIKING RANGE CORP.
BUILT-IN REFRIGERATOR / FREEZER
Tools Needed For Repair
1. Channel locks or 5/8" open end wrench
2. Medium size Phillips screwdriver
3. Medium & small straight blade screwdriver
4. Needle nose pliers
5. Socket set with medium & long extensions, socket sizes ½" to 1/4"
6. Set of nut drivers ½" to 1/4"
7. #15 Torx driver
8. Six foot step ladder
9. Sealed system equipment for R134a
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4 4

5 5

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The Freezer Compartment
The evaporator fan (1) draws air over the evaporator coils (4) located in the lower portion of the freezer
compartment. As the air passes over the evaporator, heat is extracted and the cold air travels up the back
of the freezer compartment through an air duct (2) to the top of the unit.
An air diffuser (3) at the top of the freezer compartment allows the cold air to circulate into the freezer
area and drop to the bottom of the compartment where it is drawn over the evaporator again.
Air traveling up the freezer air duct is also directed out the small diffuser (9) just below the ice maker.
The air travels along the bottom of the ice maker to the front of the freezer and down toward the bottom
of the compartment and then up through the evaporator coils (4).
The Refrigerator Compartment
An air duct regulated by a motorized air door (5) located at the top of the freezer section allows cold air to
pass through the separator wall (8) into the refrigerator section. Air then circulates throughout the
refrigerator section, generally flowing from top to bottom. As it reaches the bottom of the refrigerator
section it is drawn through a return air duct (6) in the separator (8) wall located just below the meat savor
drawer. This return air is drawn to the bottom of the freezer compartment through a passage between the
side of the evaporator (7) and the separator wall (8) and then up past the evaporator coils (4).
Cold air from the freezer section also enters the meat savor drawer through a small air duct (10) in the
separator wall (8). Air travels through the meat savor control (11). If the baffle in the meat savor control
is open, the air travels out the round port (12) into the back of the meat savor drawer. The air exits the
meat savor drawer and returns to the freezer through the return duct (6) The air then travels down
between the side of the evaporator (7) and the separator wall (8) and then up through the evaporator coils
(4).
Air Circulation In The Component Compartment
A second air circulation system in the component compartment at the top of the unit dissipates the heat
picked up by the refrigeration system ( Fig. 5). The condenser fan, located at the back of the
compartment draws room air across the condenser, absorbing the heat in the refrigerant. This warmed air
is then exhausted through a grille located at the left of the compartment behind the decorative grille
assembly.
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Motorized Air Operation
A motorized air door regulates the air flow coming from the freezer. The operation of the motorized air
door is determined by the following components:
• The temperature sensor (thermistor) located on the back wall of the refrigerator cover.
• The electronic control board located inside the refrigerator section control cover.
When the temperature sensor calls for cooling in the refrigerator section, the electronic control energizes
the air door motor and opens the baffle (Fig 6-A). from the “closed” position, the baffle rotates clockwise
270°. During this rotation it opens, closes and then parks in the “open” position. The OPEN MICRO-
SWITCH shuts the door motor off when the baffle is fully open.
When the temperature sensor is satisfied, the electronic control again energizes the air door motor and
closes the baffle (Fig 6-B). from the “open” position, the door rotates clockwise 90°and parks in the
“closed” position. The CLOSED MICRO SWITCH shuts off the door motor when the baffle is fully
closed.
Air Circulation in the Meat Savor Drawer
The Meat Savor drawer in the refrigerator compartment is provided with a separate controlled flow of
cold air from the freezer compartment. Air enters the Meat Savor drawer through an air passage through
the center divider wall into the upper part of the Meat Savor drawer control. If the control knob is rotated
fully counterclockwise the control knob arrow is pointing to “COLD” (Fig 7A). In this position the cold
air is blocked by the baffle and will not enter the Meat Savor drawer.
As the control knob is turned clockwise (toward the “COLDEST” setting), cold air will be able to pass
around the baffle into the lower part of the Meat Savor control it can flow through the round port into the
Meat Savor drawer. Air then leaves the drawer and joins the normal air circulation in the refrigerator
compartment and return to the freezer compartment through the return air ducts in the center divider wall.
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Control and Operation
The temperature controls in the built-in refrigerator/freezer are designed to regulate temperature more
accurately and operate the product more efficiently than freestanding side-by-side refrigerator/freezers.
Freezer Thermostat Control
The freezer thermostat controls the temperature of the freezer compartment be sensing cold air coming
from the cold air duct on the back wall of the freezer liner. The thermostat’s sensing tube is located in the
upper right side and upper back of the freezer compartment and is covered by plastic wiring covers
When the thermostat calls for cooling, the following components are energized:
• Compressor
• Condenser
• Defrost Timer Motor
• Freezer Side Panel Heater
In addition, the thermostat sends a signal to the electronic control board indicating that the compressor is
running. The electronic control board then energizes the evaporator fan motor. Although the evaporator
fan motor is energized independently through the electronic control board, it always runs when the
compressor is operating. This insures air circulation across the evaporator coils and through the freezer
compartment during the compressor “on” cycle.
Refrigerator Electronic Temperature Control
The refrigerator electronic temperature control system consists of a thermistor and an electronic control
board. The flexibility of the electronic control enables the refrigerator to operate with greater efficiency
by activating the motorized air door and the evaporator fan motor independently of the compressor
circuit.
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• The electronic control board continuously sends a flow of voltage, or signal current, through the thermistor.
The thermistor is sensitive to temperature fluctuations and changes resistance accordingly. When the
temperature rises in the refrigerator compartment:
• The thermistor resistance decreases, altering the signal going to the electronic control board.
• The electronic control board, sensing the change in the signal current:
a) Energizes the motorized air door to open.
b) Energizes the evaporator fan motor (if it is not already running during a compressor “on”
cycle).
When the refrigerator compartment temperature decreases:
• The thermistor resistance increases, altering the signal current to the electronic control board.
• The electronic control board sensing the change in the signal current:
a) Closes the air door.
b) Cycles the evaporator fan motor off (if the compressor is not running).
The electronic control board is operated by a variable resistor, or potentiometer, which sets the desired refrigerator
compartment temperature. Adjusting the potentiometer changes the sensitivity of the electronic control board to the
signal current from the thermistor. Varying the sensitivity raises or lowers the regulated temperature.
The refrigerator thermistor and the electronic control board directly affect the operation of the evaporator fan motor
and the motorized air door. Evaporator fan motor and motorized air door cycling may occur one or more times
before the freezer calls for a cooling cycle.
Control Interaction
The following information explains how the freezer thermostat and the refrigerator electronic temperature control
system interact.
When the freezer thermostat closes (calling for cooling):
• The cycle is initiated.
• A voltage signal is sent to the electronic control board.
• The electronic control board energizes the evaporator fan motor.
• If the thermistor is satisfied, the motorized air door remains closed.
• If the thermistor is calling for cooling, the motorized air door opens.
When the freezer thermostat opens (is satisfied):
• The cooling cycle is terminated.
• The voltage signal to the electronic control board is terminated.
• If the thermistor is satisfied, the motorized air door is closed and the evaporator fon motor is turned off.
• If the thermistor is calling for cooling, the motorized air door opens and the evaporator fan motor runs.
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