R-24AT. R22AT and R24AT Alternative - Sharp Home Appliance Service Manual (repair manual). Page 8

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1. The door release lever is pulled.
2. The upper latch head is lifted up by the linked door

release lever.

3. The head lever is lifted up by the door release lever.
4. The joint lever is lifted up by the head 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.

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.

The monitor switches SW3, SW4 are activated (the con-
tacts opened) the upper latch head and switch lever A
while the door is closed. The switch SW3 (or SW4) is
intended to render the oven inoperative by means of
blowing the fuse F1 F10A (or F2 F10A) when the contacts
of the interlock switch SW1 (or SW2) fail to open when the
door is opened.

Function
1. When the door is opened, the monitor switches SW3

+SW4 contacts close (to the ON condition) due to their
being normally closed. At this time the interlock switch
SW1+SW2 are 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

switches SW3+SW4 contacts are opened and inter-
lock switch SW1+SW2 contacts are closed (On open-
ing the door, each of these switches operate inversely.)

3. If the door is opened and the interlock switch SW1 (or

SW2) contacts fail to open, the fuse F1 F10A (or F2
F10A) blows simultaneously with closing of the monitor
switch SW3 (or SW4) contacts.

CAUTION:BEFORE REPLACING A BLOWN  FUSE F1

F10A (OR F2 F10A) TEST THE INTERLOCK
SWITCH  SW1 (OR SW2) AND MONITOR
SWITCHE SW3 (OR SW4)  FOR PROPER
OPERATION. (REFER TO CHAPTER “TEST
PROCEDURE”).

The noise filter assembly prevents radio frequency inter-
ference that might flow back in the power circuit.

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 F1 F10A (or F2 F10A) also blows when

interlock switch SW1 (or SW2) remains closed with the
oven door open and when the monitor switches SW3
(or SW4) closes.

If the wire harness or electrical components make a short-
circuit, this weak point F3 blows to prevent an electric
shock or fire hazard.

The high voltage fuse blows when the high voltage rectifier
or the magnetron is shorted.

The temperature fuses TF1, TF2 located on the top of the
upper and lower waveguide, are designed to prevent
damage to the magnetrons MG1, MG2. If an over heated
condition develops in the tube due to blower motor failure,
obstructed air ducts, dirty or blocked air intake, etc., the
circuit to the magnetrons are interrupted. Under normal
operation, the temperature fuses remains closed. How-
ever, when abnormally high temperatures are generated
within the magnetrons, the temperature fuses will open at
150˚C causing the microwave energy to stop. The defec-
tive temperature fuses must be replaced with new rated
ones.

The temperature fuse TF3, located on the side of the
exhaust duct assembly, 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 tempera-
ture fuse will open. Under normal operation, the oven
temperature fuse remains closed. However, when abnor-
mally high temperatures are generated within the oven
cavity, the oven temperature fuse will open at 120˚C,
causing the oven to shut down. The defective temperature
fuse must be replaced with new rated one.

Latch head

SW4: Monitor switch

(Oven side)

SW3: Monitor switch

Latch hook

SW1: Interlock switch

SW2: Interlock switch

(Oven side)

SW5: Stop switch

Latch head

Joint lever

Door release
lever

Head lever