Kenmore 796.405190, Service Manual

Page: 38 / 59

37
9-2. DOOR LOCK SWITCH ASSEMBLY
Circuit
diagram
Circuit in the MAIN PWB
MAIN PWB
Vdc
Vac
MICOM
12V
12V
4 1
3 2
4 1
3 2
Relay
Relay
NA4
1
2
3
4 1
2
3
4 2
3
4
PTC
PTC
Door switch
SOLENOID
5
YL
BL
RD
BK
AC
Common
terminal
of Valve
Function
The Door Lock Switch Assembly consists of a Heating PTC, a Bimetal, a
Protection PTC, and a Solenoid. It locks the door during a wash cycle.
1. Operation for door closing
- After the system turns on, PTC heating starts up through terminal 2~4’s
authorizing the power on.
- After PTC heating starts up and before solenoid operation is driven,
force the system to the off position through CAM.
Door close
- Authorizing one impulse through terminal 3~4 (PTC & solenoid) will
make the door locked.
- Door lock is detected when switches in terminal 4~5 are set closed.
CAM rotation will forcibly clear off the connection.
The maximum, allowable number of impulse authorizations is 2
Upon the third authorization of the impulse,
the position of CAM goes back to the door-open position.
- Authorizing the impulse occurs in 4.5 seconds upon input for max
performance and two authorization processes are allowed at most.
Normal operation period of PTC heating: 1.5 - 5 seconds
(Defects from the development process)
2. Operation for door opening
- With a temporary stop, door automatically opens by CAM rotations after
authorizing the impulse from the terminal 3 ~ 4 and the power turns off -
maximum of 3 times of the authorizing period
- Upon the fourth authorization of the impulse, the position of CAM goes
back to the door-close position.