Electrolux EI27MO45GSA, Technical & Service Manual, Page: 17 / 52

Operation
2-5
MONITOR SWITCH
The monitor switch is activated (the contacts opened)
by the latch head on the door while the door is closed.
The switch is intended to render the oven inoperative,
by means of blowing the C/T fuse, when the contacts of
the secondary interlock relay (RY2) and primary interlock
switch fail to open when the door is opened.
Functions:
1. When the door is opened, the monitor switch contact
close (to the ON condition) due to their being
normally closed. At this time the secondary interlock
relay, primary switch and third door switch 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
switch contacts are first opened and then the door
sensing switch, primary switch and third door switch
contacts close. (On opening the door, each of these
switches operate inversely.)
3. If the door is opened, and the secondary interlock re-
lay (RY2) and primary interlock switch contacts fail to
open, the C/T fuse blows simultaneously with closing
of the monitor switch contacts.
COOLING FAN MOTOR
The cooling fan motor drives a blade which draws in
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 vapors given off from the
heating foods. It is then exhausted through exhausting air
vents at the oven cavity.
Before replacing a blown C/T fuse, test the door
sensing switch, secondary interlock relay (RY2),
relay (RY1), primary/third door interlock switch and
monitor switch for proper operation. (Refer to
Section 3 “Test procedure”).
C/T fuse and monitor switch are replaced as an
assembly.
TURNTABLE MOTOR
The turntable motor rotates the turntable located on the
bottom of the oven cavity, so that foods on the turntable
cook evenly during cooking. The turntable may turn in
either direction.
MONITOR FUSE
1. The monitor fuse blows when the contacts (COM-
NO) of the primary switch 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 monitor fuse blows to prevent an
electric shock or fire hazard.
CAVITY TEMPERATURE FUSE
The cavity 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 cavity tempera-
ture fuse will open. Under normal operation, the cavity
temperature fuse remains closed. However, when
abnormally high temperatures are reached within the
oven cavity, the cavity temperature fuse will open at
302°F (150°C) causing the oven to shut down.
NOTE: The fuse must be replaced, it does not reset.
C/T TEMPERATURE FUSE
The C/T fuse, located near the magnetron, is designed to
prevent damage to the magnetron if an over heated
condition develops in the tube due to cooling fan failure,
obstructed air guide, dirty or blocked air intake, etc.
Under normal operation, the C/T fuse remains closed.
However, when abnormally high temperatures are
reached within the magnetron, the C/T fuse will open at
302°F (150°C) causing the oven to shut down.
1. The C/T fuse blows when the contacts (COM-NO) of
the secondary interlock relay (RY2) and primary
interlock switch 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 monitor fuse blows to prevent an
electric shock or fire hazard.
NOTE: The fuse must be replaced, it does not reset.