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English
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Service Manual
Yate Production Dryers
Edition
2006.09.21
2.3
ELECTRONIC CONTROL LOgIC
Estimate of programme duration on the basis of communication between the two
NTC sensors and the conductivity sensor.
The method for calculating the duration of programmes is as follows:
•
Each drying cycle includes a procedure, active for the first 10’, in which the controller establishes the
type of load, and in particular the moisture content.
•
With the programme selected, the dryer runs cold for a period of 10 minutes during which the software,
interacting with the front and rear NTC sensors and the conductivity sensor, will calculate the time nee-
ded to complete the cycle. During this initial stage, the display will show a maximum programme time of
2 hours and 20 minutes (Ariston with display).
Electrical and electromechanical loads and duration of single programmes
Electronic condenser and vented dryers.
Once the 10 minutes moisture content detection time has elapsed, the rear NTC sensor enables activation
of the loads and the drying programme starts.
The static heating element is always on, whereas the dynamic element cycles on and off according to the
temperature at the front NTC sensor.
The front NTC sensor measures the temperature of the air leaving the drum, the rear NTC sensor mea-
sures the temperature in the heater enclosure; the conductivity sensor monitors moisture in the load and
combines with the two NTCs to determine the duration of the programme.
As the moisture content drops, the temperature at the front of the drum approaches the temperature at the
rear.
This calculation is repeated every 40 seconds approx. The conductivity sensor, to which an input current
is applied at 5 Vdc, measures the moisture content of the load by way of a sensing strip wired to the GND
connection on the mainboard. The control module compares the resistance with a known reference value
for the selected programme and, utilizing algorithms and the readings from the front and rear NTC sensors,
proceeds to compute the cycle time remaining.
2.4
ELECTROMEChANICAL CONTROL LOgIC
Electromechanical condenser dryers
.
The programme of electromechanical dryers is governed by a heat switch (if installed) on the control panel
(selects high or low temperature), a programmer, and a thermostat located in the front air duct. The user
selects high or low temperature by way of the switch, and sets the duration of the cycle by selecting the
desired programme with the programmer. At the start of the programme, the heating element is on and the
temperature controlled by a thermostat positioned on the front air duct, which will pilot the element to cut
in and out as necessary until the cooling stage is reached.
Electromechanical vented dryers.
The programme of electromechanical dryers is governed by a heat switch, a programmer, and a thermostat
located in the front air duct. The user selects high or low temperature by way of the switch, and sets the
duration of the cycle with the programmer. At the start of the programme, the heating element is on and the
temperature controlled by a thermostat positioned on the front air duct, until the moment when the timer
switches to the cooling stage.
