Service manual

Component descriptions
Components and function description
Here we describe the function and
specification of the most important
components. Certain components are found
only in more highly specified machines or in
particular markets. See the Troubleshooting
chapter for fault and information codes.
CU (Control Unit)
The CU (Control Unit) functions as both a
control panel and a logic component. The
control panel is equipped with knobs/buttons
for selecting programs, Start/Stop buttons and
a display. It is an integrated part of the CU
and cannot be replaced separately. The logic
component manages functions needed for
drying programs and diagnosis. The CU has an
internal power supply for the logic component.
In the event of a fault, the CU can diagnose
a number of components and functions, and
a total of 4 fault codes can be displayed. To
facilitate troubleshooting there is a component
testing function in which the outputs are
activated according to a special sequence.
Power supply
Mains voltage, built-in internal voltage
converter for the logic component.
Light
Certain machines have an internal light
that is activated when the door is opened.
LED technology is used to improve energy
efficiency.
Thermistors
The thermistors are of the NTC type (Negative
Temperature Coefficient), which means their
resistance decreases as temperature increases.
Thermistor 1 is in the air duct on the front frame,
after the internal impeller. If there is an interruption
in the thermistor circuit or if it short circuits, the
drying program stops and the display shows
“Thermistor fault”.
Purpose: Measures the temperature of the air that
has passed the load and controls the drying process
and the heating element.
Thermistor 2 is on condenser dryers located after the
condenser and on heat pump dryers located on the
evaportator pipe by the comperssor.
Purpose: Measures the temperature of the
dehumidified air, the value of which is used as a
parameter in the drying process.
Resistance values for thermistors 1 and 2
Temperature Resistance
20°C 5989
25°C 4869
30°C 3946
35°C 3197
40°C 2598
45°C 2126
50°C 1758
55°C 1471
60°C 1240
65°C 1043
70°C 857
Tolerance: ±1%
Service Manual TD70
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