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R259(W)
6 – 1
R259(W)
Service Manual
CHAPTER 6.
FUNCTION OF IMPOR-
TANT COMPONENTS
[1] DOOR OPEN MECHANISM
The door is opened by pulling the door, refer to the Figure D-1.
Figure D-1. Door Open Mechanism
[2] 1ST. LATCH SWITCH AND 2ND. INTER-
LOCK RELAY CONTROL SWITCH
LOCK RELAY CONTROL 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.
[3] 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, the relay (RY1) and the 2nd. interlock relay (RY2) fail
to open, the fuse (T6.3A) blows simultaneously with closing the
contacts (COM-NC) of the monitor switch.
to open, the fuse (T6.3A) blows simultaneously with closing the
contacts (COM-NC) of the monitor switch.
CAUTION: BEFORE REPLACING A FUSE (T6.3A) TEST THE 1ST.
LATCH SWITCH, RELAY (RY1) AND 2ND. INTERLOCK
RELAY (RY2) AND MONITOR SWITCH FOR PROPER
OPERATION. (REFER TO CHAPTER “TEST PROCE-
DURE”.)
RELAY (RY2) AND MONITOR SWITCH FOR PROPER
OPERATION. (REFER TO CHAPTER “TEST PROCE-
DURE”.)
[4] FUSE T6.3A
1. The fuse (T6.3A) blows when the contacts (COM-NO) of the 1 st.
latch switch, the relay (RY1) and the 2nd. interlock relay (RY2)
remain closed with the oven door open and when the monitor
switch closes.
remain closed with the oven door open and when the monitor
switch closes.
2. If the wire harness or electrical components are short-circuited, the
fuse (T6.3A) blows to prevent an electric shock of fire hazard.
[5] HIGH VOLTAGE FUSE
The high voltage fuse blows when the high voltage rectifier or the mag-
netron is shorted.
netron is shorted.
[6] TEMPERATURE FUSE 150C (OVEN)
The temperature 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 temperature fuse remains
closed. However, when abnormally high temperatures are reached
within the oven cavity, the temperature fuse will open at 150
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 temperature fuse remains
closed. However, when abnormally high temperatures are reached
within the oven cavity, the temperature fuse will open at 150
°C, caus-
ing the oven to shut down. The defective temperature fuse must be
replaced with a new one.
replaced with a new one.
[7] TURNTABLE MOTOR
The turntable motor drives the turntable roller assembly to rotate the
turntable.
turntable.
[8] FAN MOTOR
The fan motor drives a blade which draws external cool air. This cool
air is directed through the air vanes surrounding the magnetron and
cools the magnetron. This air is channelled through the oven cavity to
remove steam and vapours given off from the heating foods. It is then
exhausted through the exhausting air vents at the oven cavity.
air is directed through the air vanes surrounding the magnetron and
cools the magnetron. This air is channelled through the oven cavity to
remove steam and vapours given off from the heating foods. It is then
exhausted through the exhausting air vents at the oven cavity.
[9] NOISE FILTER
The noise filter prevents the radio frequency interference that might
flow back in the power circuit.
flow back in the power circuit.
Latch Heads
Latch Hook
Door
2nd. Interlock Relay
Control Switch
Control Switch
1st. Latch Switch
Monitor Switch
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