Service manual

SOI/DT 2007-02 dmm 49/66 599 38 61-92
9.2.2 Instantaneous door interlock
• With this safety device it is possible to open the door immediately after the end of the cycle.
9 Door interlock
19 Suppressor
20 PCB
ON/OFF = Main switch (programme
selector)
9.2.2.1 Operating principle
ª When the ON/OFF switch closes and the appliance is switched on, power is applied to the bimetallic
PTC switch (contact 4-2), but the door remains unlocked.
ª When the programme starts (Start/Pause button), the main board sends a 20 msec pulse to contacts 4-
3 on the solenoid (at least 6 seconds must have passed since the appliance was switched on). This
locks the door and simultaneously closes the main switch (contacts 4-5), thus applying power to all
components on the appliance.
ª When the programme ends, the main board sends two additional 20 msec pulses (200 msec apart):
- the first pulse does not unlock the door
- the second pulse (which is sent only if the appliance is operating properly) unlocks the door lock
device and simultaneously opens the contacts on the main switch.
9.2.2.2 Conditions required for opening the door
ª Before pulses are sent to open the door, the main board checks for the following conditions:
- The drum must not be moving (no signal from the tachometric generator).
- The water level must not be higher than the bottom of the door.
- The water temperature must not exceed 40º C.
9.2.2.3 Automatic unlock
If a power failure occurs, if the appliance is shut off, or if the solenoid malfunctions, the bimetallic PTC will cool
down and the door will unlock in 1 - 4 minutes.