LG MH-1355M Service Manual page 21

CONVECTION COOKING SYSTEM (FIG. 12)
Convection cooking is not performed by direct heat
from the heating elements, but by forced circulation of
the hot air produced by the heating elements located
at the back side of the oven cavity.
The air heated by the heating elements (heater) is
circulated through the convection chamber of the
oven cavity by means of the circulation fan which is
driven by the circulation motor.
Then the hot air enters the inside of oven through the
vent holes provided in the back plate of the oven
cavity. Next the hot air heats up the food on the turn-
table and leaves the oven cavity through the vent in
the centre of the oven cavity back side. In a continuous
cycle, this hot air is reheated by the heater, passes
through the back chamber (convection chamber) and
enters the inside of the oven cavity again. In this way,
the hot air raises inside air temperature of the oven
cavity and thus the food is being cooked. Convection
heater will heat continuously before the setting tem-
perature is reached, and alternates on and off accord-
ing to temperature after the setting temperature is
reached.
The on/off of the convection heater is controlled by
thermistor.
CIRCULATION FAN
CONVECTION
HEATER
Fig. 12
– 21 –
CHAMBER ASSEMBLY (FIG. 12)
The air heated by the heating element is circulated
through the convection passage provided on the back
side of the oven by means of the convection fan which
is driven by the convection motor. It then enters the
inside of oven through the vent holes provided on the
rear of the oven cavity. Next, the hot air heats up the
food on the turntable and leaves the oven cavity
through the vent in the centre of the oven cavity rear
wall.
Without leaving the oven, this hot air is reheated by
the heating element, passes through the convection
passage and enters the inside of the oven cavity
again, in a continuing cycle.
DAMPER OPERATION
When the oven starts convection and combination
function, damper bracket is pulled by solenoid so that
the hot air does not leave the cavity.
When the function is microwave, the power supply to
the solenoid is turn off and damper spring push the
damper bracket so that the fan circulate the air within
the cavity.
FOOD
CONVECTION RACK