Viking VHSO205SS Service Manual page 14

VHSO205SS
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will open at 30 F (150 C) causing the oven to shut down.
When the thermal cut-out has cooled, the thermal cut-out
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closes at 66 F (130 C).
TOP HEATING ELEMENT
The top heating element is located at the top of the oven
cavity. It is intended to heat air driven by the convection fan.
The heated air is kept in the oven and force-circulated and
reheated by the top heating element.
SIDE HEATING ELEMENT
The side heating element is located at the left side of the
oven cavity. It is intended to heat air driven by the convection
fan. The heated air is kept in the oven and force-circulated
and reheated by the top heating element.
TURNTABLE MOTOR
The turntable motor rotates the turntable located in the
bottom of the oven cavity, so that the food on the turntable
is cooked evenly during cooking. The turntable may turn in
either direction.
FAN MOTOR (MAGNETRON SIDE)
The fan motor drives a blade which draws external cool air.
This cool air is directed through the air vents surrounding the
magnetron and cools the magnetron. This air is channelled
through the oven cavity to remove steam and vapors given
off from the heating foods. It is then exhausted through the
exhausting air vents at the oven cavity.
FAN MOTOR (POWER TRANSFORMER SIDE)
The fan motor drives a blade which draws external cool air.
This cool air is directed through the air vents surrounding the
power transformer and cools the power transformer. This air
is channelled through the oven cavity to remove steam and
vapors given off from the heating foods. It is then exhausted
through the exhausting air vents at the oven cavity.
CONVECTION COOKING SYSTEM
This oven is designed with a hot air heating system where
food is not directly heated by the heating element, but is
heated by forced circulation of the hot air produced by the
heating elements. The air heated by the heating elements is
circulated through the convection passage provided on the
outer casing of the oven cavity by means of the convection
fan which is driven by the convection motor. It then enters
the inside of the oven through the vent holes provided on
the top and left sides of the oven. Next, the hot air heats the
food on the turntable and leaves the oven cavity through the
vent in the center of the oven cavity back side wall. Without
leaving the oven, this hot air is reheated by the heating ele-
ments, passes through the convection passage and enters
the inside of the oven cavity again, in a continuing cycle.
In this way, the hot air circulates inside the oven cavity to
raise its temperature and, at the same time, comes into
contact with the food being cooked. When the temperature
inside the oven cavity reaches the selected temperature, the
heating elements are de-energized. When the temperature
inside the oven cavity drops below the selected temperature,
the heating elements are energized again. In this way, the
inside of the oven cavity is maintained at approximately the
selected temperature. When the convection time reaches 0,
the heating elements are de-energized and the convection
fan stops operating and the oven shuts off.
Flow of hot air:
The rotation direction of the convection motor is controlled
by relay RY6. When the convection fan rotates clockwise,
the hot air from the oven cavity left side wall blows stronger
than one from the oven cavity top wall. ( This mode is called
"Convection mode".) When the convection fan rotates coun-
terclockwise, the hot air from the oven cavity top wall blows
stronger than one from the oven cavity left side wall. (This
mode is called "JET mode".)
Top heating
element unit
Side heating
element unit
Convection
fan
FRONT VIEW
Figure D-2. Rotation direction of convection fan
Oven cavity left side
Hot air
Top heating element unit Top heating element unit
Hot air
Side heating
Turntable
element unit
Convection Mode
Figure D-3. Flow of hot air
DAMPER OPEN-CLOSE MECHANISM
Usually, the damper is in the open position except during
convection cooking, reheat, speed grill, speed roast, speed
bake, or all cooking modes which use the top / side heating
elements. Damper position is set automatically by damper
motor, damper switch, motor cam and damper shaft. These
components are operated by a signal that judges if micro-
wave cooking, convection cooking operation or other cooking
14
JET
mode
Convection mode
Hot air
Oven cavity
top wall
Convection
fan
Side heating
element unit
JET Mode
Hot air