Maico WS 170 L Notice D'installation page 71

9.3.1 Procedure in the case of fan failure
Danger to life from electric
shock.
DANGER Never touch live components.
1. Check the function of the door contact
switch [7]. Replace this if necessary.
If the front door is closed (door
contact switch [7] is activated), there
is a 230 V AC supply voltage to the
terminal pairs "X" and "Y" of the "A2"
control circuit board  Chapter 6.7
Electrical connection.
2. With the door contact switch [7] actuated,
check the 230 V AC exhaust air and
supply air fan supply voltage to the
terminal pairs "X" and "Y".
3. Delete the fault message as described in
Chapter 9.1.
The 1.7 to 10 V DC fan control voltage is then
present for around 1 minute on the plug pins
of the "A2" control circuit board.
The fault message now appears again.
9. Faults, messages │ uk
4. Check the supply air and exhaust fan
control voltage at the plug pins: supply air
side on pins 1 and 3, exhaust air side on
pins 5 and 3.
5. The control voltage for both the supply
air and exhaust fan is in each case
1.7...10 V DC.
6. Replace the circuit board or fans if
necessary
9.3.2 Temperature sensor fault
The ventilation unit goes into fault mode if the
internal frost protection temperature sensor
fails (short-circuit, cable break or because it is
not connected).
Both fans switch off immediately. The fault
message on the room air control goes out
after approx. 1 minute (no LED lit up any
more), both fans remain switched off.
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