6
R-7A55(W)/(B)
R-7E45(W)/(B)
FUNCTION OF IMPORTANT COMPONENTS
DOOR OPEN MECHANISM
The door can be opened by pushing the open button on the
control panel. When the open button is pushed, the open
lever pushes lower latch head on the door upward. The
upper latch head is linked with the lower latch head, so now,
the door can be opened.
FUSE F1 15A 250V
If the wire harness or electrical components are short-
circuited, this fuse F1 15A 250V blows to prevent an electric
shock or fire hazard.
FUSE F2 F6.3A 250V
1. If the wire harness or electrical components are short-
circuited, this fuse blows to prevent an electric shock or
fire hazard.
2. The fuse also blows when 1st latch switch SW1 remains
closed with the oven door open and when the monitor
switch SW4 contact (COM-NC) closes.
FUSE F3 F10A 250V
1. If the wire harness or electrical components are short-
circuited, this fuse blows to prevent an electric shock or
fire hazard.
2. The fuse also blows when the asymmetric rectifier, H.V.
rectifier,.H.V. wire harness, H.V. capacitor, magnetron or
secondary winding of high voltage transformer is shorted.
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 circuit.
Figure D-1. Door Open Mechanism
1ST LATCH SWITCH SW1, 2ND LATCH
SWITCH SW2 AND STOP SWITCH SW3
1. When the oven door is closed, the contacts COM-NO of
each switch must be closed.
2. When the oven door is opened, the contacts COM-NO of
each switch must be opened.
MONITOR SWITCH SW4
The monitor switch is activated (the contacts opened) by the
lower latch head on the door while the door is closed. The
switch is intended to render the oven inoperative 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 contacts (COM-NC) of
monitor switch SW4 close (to the ON condition) due to
their being normally closed and contacts (COM-NO)
open. At this time the 1st latch 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
SW3 contacts (COM-NC) are opened and contacts (COM-
NO) closed and 2nd latch switch SW2 contacts COM-NO
are closed and then the 1st latch switch and stop switch
contacts close.(On opening the door, each of these
switches operate inversely.)
3. If the door is opened and the 1st latch switch SW1
contacts fail to open, the fuse F2 (F6.3A) blows
immediately after closing of the monitor switch (COM-
NC) contacts.
CAUTION: BEFORE REPLACING A BLOWN FUSE F2
F6.3A TEST THE 1ST LATCH SWITCH, MONI-
TOR SWITCH AND MONITOR RESISTOR FOR
PROPER OPERATION.
(REFER TO CHAPTER “TEST PROCEDURE”).
TC TRANSFORMER
TC transformer converts A.C. line voltage into low voltage to
drive the control unit.
THERMAL CUT-OUT TC1 170˚C (OVEN)
The thermal cut out protects the oven against overheat
during grill cooking, convection cooking or dual (combina-
tion) cooking. If the temperature rises above 170˚C because
the fan motor is interrupted, the air inlet duct is blocked or the
ventilation openings are obstructed, the thermal cut-out
opens and switches off the all electrical parts.
The defective thermal cut-out must be replaced with a new
one.
THERMAL CUT-OUT TC2 125˚C (MG)
This thermal cut-out protects the magnetron against over-
heat. If the temperature goes up higher than 125˚C because
the fan motor is interrupted or the ventilation openings are
blocked, the thermal cut-out TC2 will open and line voltage
to the high voltage transformer T will cut off and operation of
the magnetron MG will be stopped. The defective thermal
cut-out must be replaced with a new one.
THERMAL CUT-OUT TC3 190˚C (CONV.)
The thermal cut out protects the convection motor CM
against overheat. If the temperature of the thermal cut-out
TC3 rises above 190˚C because the convection fan is
interrupted, the ventilation openings are obstructed or the
other abnormal matter occurs, the thermal cut-out opens and
switches off the convection heating element and conv.
indicator light. When the oven cools itself down to the
operating temperature of 170˚C, the contacts of the thermal
cut-out will close again.
LATCH
HEADS
LATCH HOOK
STOP
SWITCH
MONITOR
SWITCH
1ST. LATCH
SWITCH
OPEN LEVER
DOOR OPEN BUTTON
2ND. LATCH
SWITCH
