KAMAZ 5490 Operation Manual page 221

4.6 The source of heat is gases got from burning
of air-fuel mixture in the combustion chamber. Hot gases
moving through the blades inside the heat exchanger
warm it and the cooling liquid that washes the heat
exchanger from outside is heated and sends this heat into
the cooling system.
4.7 The operation of the heater is carried out by
the control panel which must be located on the dash
panel of a motor vehicle. On the front board of the panel
a handhold position 1 (figure 3) of potentiometer is
inserted for controlling the air temperature inside the
vehicle cabin. The temperature can be set from +15 °С
till +30 °С.
A button position 2 and a button position 3 are
also located on the front board of the panel. Each of them
is assigned for starting and switching the heater.
Two light-emitting diodes are also output on the
front board of the panel (see figure 3). They show the
condition of the heater:
- it doesn't glow , the heater doesn't work;
- it glows green, the heater works;
- it flickers with intervals and beeps (the
malfunction code), the heater is out of order.
Fig. 3. The Control panel board
4.8 After pushing the startup button of the heater
the control panel diagnoses all the operation system
elements and their electric circuits. If all the elements are
operable the control panel begins the work of the heater
under the set program. When button position 2 is pushed
the heater starts working under program № 1 and when
button position 3 is pushed – under program № 2.
Startups under programs № 2 and № 1 don't
differ from each other until the heater reaches the
medium operating mode.
In the beginning the control unit gradually boosts
the voltage in the glow plug; the cellular structure in the
combustion chamber is heated. Then fuel and air are
supplied, which begins the process of burning that is
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