GE PT920 Technical Service Manual page 27

Lock Assembly
The motorized door lock assembly is located above
the oven. The assembly consists of a lock motor
cam and switch assembly, lock hook, mounting
plate, door switch, spring, and plunger.
The lock motor is energized when the control is set
for Clean and Clean Time is selected. The K9 relay
contact will close and complete the circuit that
supplies the voltage to the lock motor.
SINGLE/UPPER OVEN
CIRCUIT TERMINALS
Oven Sensor 9 to 10
Door Latched 5 to 6
4 to 6
Door Unlatched 4 to 6
5 to 6
LOWER OVEN (Double Wall Oven Only)
CIRCUIT TERMINALS
Oven Sensor 9 to 10
Door Latched 4 to 5
3 to 5
Door Unlatched 3 to 5
4 to 5
Door Locking/Unlocking Strip Circuit
K9
LOCK RELAY
L
MOTOR
C MDL
The lock motor has approximate resistance value of
1.9K Ω.
Note:
• To enable proper operation of the door lock,
ensure that the door jamb switch is in "common"
to "normally closed" (door closed). This enables
power to be delivered when the door lock closes.
• Display of control will fl ash
switch is in the "C" (common) to "NC" (normally
open) position (door open).
• The word "LOCKED" will fl ash on and off in the
display while the lock motor is in motion. When
the door is locked, the word "LOCKED" remains
illuminated in the display.
OHMS
1091Ω @ Rm Temp.
1654Ω @ 350°F
2634Ω @ 865°F
0Ω
open
0Ω
open
OHMS
1091Ω @ Rm Temp.
1654Ω @ 350°F
2634Ω @ 865°F
0Ω
open
0Ω
open
LOCK N
"LOCKED" if the door
The cam on the motor performs two functions:
1. Positions the lock hook in the door to prevent
opening during clean operation.
2. Operates the lock switches, which signal the
control if the door is unlocked or locked and
ready for clean operation.
Note: When door is either being locked or unlocked,
both the lock and unlock switches will be in the open
position. The locked and unlocked diagrams are
representative of a single/upper oven but apply also
to a lower oven.
Door Lock - Locked Position
Unlock Switch
Door
Switch
BU
Y
UNLOCK SW
Y
– 27 –
Motor
Lock Switch
Hook
Plunger
Strip Circuit
LOW TEMP
THERMAL SW
BU
O
LOCK SW
LOCKED
(Continued Next Page)
4
5
6