5
R-2277
R-2287
MONITOR SWITCH SW4
The monitor switch is activated (the contacts opened) the
upper latch head and switch lever A while the door is
closed. The switch is intended to render the oven inopera-
tive by means of blowing the fuse F2 F6.3A when the
contacts of the 1st latch switch SW1 fail to open when the
door is opened.
Function
1. When the door is opened, the monitor switch SW4
contacts close (to the ON condition) due to their being
normally closed. At this time the 1st latch switch SW1
is in the OFF condition (contacts open) due to their
being normally open contact switches.
2. As the door goes to a closed position, the monitor
switch contacts are opened and 1st latch switch con-
tacts are closed (On opening the door, each of these
switches operate inversely.)
3. If the door is opened and the 1st latch switch contacts
fail to open, the fuse F2 F6.3A blows simultaneously
with closing of the monitor switch contacts.
CAUTION:BEFORE REPLACING A BLOWN FUSE F2
F6.3A TEST THE 1ST LATCH SWITCH,
MONITOR SWITCH AND MONITOR RESIS-
TOR FOR PROPER OPERATION. (REFER
TO CHAPTER “TEST PROCEDURE”).
MONITOR RESISTOR R1
The monitor resistor prevents the fuse F2 F6.3A 250V
bursting when the fuse F2 F6.3A 250V blows due to the
operation of the monitor switch.
NOISE FILTER
The noise filter assembly prevents radio frequency inter-
ference that might flow back in the power circuit.
WEAK POINT (R-2287)/ FUSE (R-2277) F1
If the wire harness or electrical components make a short-
circuit, this weak point/ Fuse F1 blows to prevent an
electric shock or fire hazard.
DOOR OPEN MECHANISM
1. The door release lever is pulled.
2. The upper latch head is lifted up by the linked door
release lever.
3. The latch lever is lifted up by the door release lever.
4. The joint lever is lifted up by the latch lever.
5. The lower latch head is lifted up by the joint lever.
6. Now both latch heads are lifted up, so they can be
released from the latch hook.
7. Now the door can be opened.
Latch head
Monitor switch
Latch hook
1st. latch switch
2nd. latch switch
Stop switch
3rd. latch switch
Latch head
Joint lever
Door release
lever
Figure D-1. Door Open Mechanism
1ST LATCH SWITCH SW1, 2ND LATCH SWITCH
SW2, 3RD LATCH SWITCH SW3 AND STOP
SWITCH SW5
1. When the oven door is closed, the contacts COM-NO
must be closed.
2. When the oven door is opened, the contacts COM-NO
must be opened.
COMMERCIAL
FREQUENCY
(50HZ)
POWER OUTPUT
BY MAGNETRON 1
POWER OUTPUT
BY MAGNETRON 2
OPERATION OF
MAGNETRON
magnetron can be oscillated alternatively according to the
frequency of the power supply. Refer to the Figure 1 and 2.
Figure B-1. High Voltage Circuit
Figure B-2. Operation of Magnetron
FUNCTION OF IMPORTANT COMPONENTS
T1: HIGH VOLTAGE
TRANSFORMER
ASYMMETRIC
RECTIFIER
H. V. RECTIFIER
C1: H.V. CAPACITOR
MG1: MAGNETRON (UPPER)
(REAR)
ASYMMETRIC
RECTIFIER
H. V. RECTIFIER
C2: H.V. CAPACITOR
MG2: MAGNETRON (LOWER)
T2: HIGH VOLTAGE
TRANSFORMER
(FRONT)
