Chapter 6. Function Of Important Com; Door Open Mechanism; 1St. Latch Switch And 2Nd. In- Terlock Relay Control Switch; Monitor Switch - Sharp R-350Y Service Manual

R-350Y(S)
CHAPTER 6.

[1] DOOR OPEN MECHANISM

The door is opened by pushing the open button on the control panel,
refer to the Figure D-1.
When the open button is pushed, the open button pushes up the
switch lever, and then the switch lever pushes up the latch head. The
latch heads are moved upward and released from latch hook. Now the
door will open.
Door
Latch
Heads
Figure D-1. Door Open Mechanism
[2] 1ST. LATCH SWITCH AND 2ND. INTER-
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 and 2nd. interlock relay fail to open, the fuse F10A
blows simultaneously with closing the contacts (COM-NC) of the
monitor switch.
CAUTION: BEFORE REPLACING A BLOWN FUSE F10A TEST THE
1ST. LATCH SWITCH, 2ND.INTERLOCK RELAY, MONI-
TOR SWITCH AND MONITOR RESISTOR FOR PROPER
OPERATION.

[4] FUSE F10A

1. The fuse F10A blows when the contacts (COM-NO) of the 1st. latch
switch and 2nd. interlock relay remain closed with the oven door
open and when the monitor switch closes.
2. If the wire harness or electrical components are short-circuited, this
fuse F10A blows to prevent an electric shock or fire hazard.

[5] INVERTER UNIT

The inverter unit converts the rated voltage into high-voltage and high-
frequency current and drives the magnetron.
FUNCTION OF IMPORTANT COMPONENTS
Latch Hook
2nd. Interlock
Relay Control
Switch
Monitor Switch
1st Latch Switch

[6] OVEN TEMPERATURE FUSE

The temperature fuse, located on the top of the oven cavity, is
designed to prevent damage to the oven by fire. If the food load is
overcooked, by either error in cook time or defect in the control unit,
the temperature fuse will open.Under normal operation, the tempera-
ture fuse remains closed. However, when abnormally high tempera-
tures are reached within the oven cavity, the temperature fuse will
open at 150 C, causing the oven to shut down.

[7] TURNTABLE MOTOR

The turntable motor drives the turntable roller assembly to rotate the
turntable.

[8] FAN MOTOR

The fan motor drives a blade which draws external cool air.This cool
air is directed through the air vents 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.

[10] HUMIDITY SENSOR

This sensor detects the humidity from the food which is being cooked,
to control its automatic cooking.
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