Primary / secondary latch switches
These are safety switches, and their basic function is to interrupt the power
supply to the magnetron when the door starts to open. They are open when the
door is opened.
Switch position
Switch
Door Opened
Door Closed
Primary Open Close
Secondary Open
Close
Table 1
Short switch
This switch is used to prevent the operation of the microwave oven while the
door is opened.
The short switch creates a short circuit to blow the line fuse and stop microwave
oven’s operation if the door switches fail to open when the door is opened.
This switch is normally open when the door is closed.
Switches Location
Primary Switch
Short Switch (Lower)
Secondary Switch (Upper)
Side view of Microwave Oven
Figure 6
Note:
When the fuse is blown due to operation of the short switch, replace the
primary switch, the short switch, the secondary switch, and the power relay.
6
