Door Lock - Panasonic NA-127VB3WDA Service Manual

11.9. Door Lock

Door lock is activated at the beginning of the program in order
to prevent the door from opening. Locking is generated by sup-
plying power to PTC-bimetal, after max 6sec (220V), the
bimetal will be warm and ready to close the contacts. Thus the
first impulse to the solenoid will allow the contact to close and
consequently the slider will be locked by the pin of the slider-
lock. The second impulse causes no electrical and mechanical
modifications. It can be unlocked by the third impulse; the con-
tact is opened even if the PTC-bimetal remains energized.
Emergency Opening System (PTC-Bimetal) In Case of Lack
of Electric Energy
• In case of lack of electric energy during a washing cycle, the
PTC-bimetal assembly will cool down and after minimum 60
sec (considering previous power supply of 30 sec min and
T=20 °C) the door will be unlocked and thus can be opened.
• In case the door is closed when current comes back, the
PTC-bimetal assembly will heat again, the slider-lock will
lock, the contact will close and the program will continue
from where it stopped.
11.9.1. Technical Features
Nominal voltage 250 V
11.9.2. Checking of Component
Check the resistance value on the component with multi-meter
as shown in below figures.
Resistance value on the (PTC overload + solenoid) should be
240Ω ±20% at 25 °C. That resistance value can be measured
from terminal 3-4 (refer to 13 Wiring Connection Diagram).
41