R-2S56
5
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the
control panel, When the open button is pushed, the switch
lever on the latch hook is moved upward, operating the latch
head. The latch head is moved upward, and released from
latch hook. Now, the door can be opened.
LATCH HOOK
1ST. LATCH SWITCH
2ND. LATCH SWITCH
MONITOR SWITCH
LATCH
HEADS
SWITCH LEVER
DOOR OPEN BUTTON
DOOR
STOP SWITCH
Figure D-1. Door Open Mechanism
1ST. LATCH SWITCH, 2ND. LATCH SWITCH AND
STOP SWITCH
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.
MONITOR SWITCH
1. When the oven door is closed, the contacts (COM-NC)
must be opened.
2. When the oven door is opened, the contacts (COM-NC)
must be closed.
3. If the oven door is opened and the contacts (COM-NO)
of the 1st latch switch and 2nd latch switch fail to open,
the fuse blows simultaneously with closing the contacts
(COM-NC) of the monitor switch.
CAUTION: BEFORE REPLACING A FUSE TEST THE
1ST LATCH SWITCH, 2ND LATCH SWITCH,
MONITOR SWITCH AND MONITOR RESIS-
TOR FOR PROPER OPERATION. (REFER
TO CHAPTER "TEST PROCEDURE")
MONITOR RESISTOR R 0.8
Ω
20W
The monitor resistor prevents the fuse bursting when the
fuse blows due to the operation of the monitor switch.
ASYMMETRIC RECTIFIER
The asymmetric rectifier is a solid state device that prevents
current flow in both directions. And it prevents the tempera-
ture rise of the power transformer by blowing the fuse when
FUNCTION OF IMPORTANT COMPONENTS
the high voltage rectifier is shorted.
D2
D1
ASYMMETRIC
RECTIFIER
HIGH VOLTAGE RECTIFIER
A
B
C
The rated peak reverse voltage of D1 of the asymmetric
rectifier is 6 KV The rated peak reverse voltage of D2 of the
asymmetric rectifier is 1.7 KV. D1 and D2 of the asymmetric
rectifier or high voltage rectifier are shorted when the each
peak reverse voltage goes beyond the each rated peak
reverse voltage. (The process of blowing the fuse.)
1. The high voltage rectifier is shorted by any causes when
microwave cooking.
2. The peak reverse voltage of D2 of the rectifier goes
beyond the rated peak reverse voltage 1.7 KV in the
voltage doubler circuit.
3. D2 of the rectifier is shorted.
4. The large electric currents flow through the high voltage
winding of the power transformer.
5. The large electric currents beyond M6.3A flow through
the primary winding of the power transformer.
6. The fuse blows by the large electric currents.
7. The power supply to the all electrical parts are cut off.
FUSE
1. The fuse blows when the contacts (COM-NO) of the 1st
latch switch and 2nd latch switch remain closed with the
oven door open and when the monitor switch closes.
2. The fuse also blows when asymmetric rectifier, H.V.
rectifier, H.V. wire harness, H.V. capacitor, magnetron or
secondary winding of power transformer is shorted.
3. If the wire harness or electrical components are short-
circuited, this fuse blows to prevent an electric shock or
fire hazard.
TEMPERATURE FUSE 150˚C (MG)
This fuse protects the magnetron against overheating. If the
temperature goes up higher than 150˚C because the fan
motor is interrupted, the air inlet duct is blocked or the
ventilation openings are obstructed, the fuse blows and cuts
off the power supplying to the power transformer.
The defective fuse must be replaced with new rated one.
TEMP. FUSE 150˚C (OVEN)
The temp. fuse located on the top of the oven cavity is
designed to prevent damage to the oven if the foods in the
oven catch fire due to over heating produced by improper
setting of cook time or failure of control unit.
Under normal operation, the temp. fuse remains closed.
However, when abnormally high temperatures are reached
within the oven cavity, the temp. fuse will open at 150˚C,
causing the oven to shut down. The defective fuse must be
replace with a new one.
