Description And Function Of Components - Electrolux E30SO75ESS Service Manual

DOOR OPEN MECHANISM
The door is opened by pulling the door handle down and
forward, referring to the figure D-1. When the door handle is
pulled down, the latch heads are moved upward. And then
when the door handle is pulled forward, the latch heads are
released from the latch hooks right and left. Now, the door
will open.
Monitor switch
Latch
head
Door handle
Figure D-1. Door Open Mechanism
DOOR SENSING AND SECONDARY INTERLOCK
SWITCHES
The door sensing switch in the primary interlock system is
mounted in the lower position on the latch hook right, the
secondary interlock switch is mounted in the lower position on
the latch hook left. They are activated by the latch heads on
the door. When the door is opened, the switches interrupt the
circuit to all components except for the oven lamp. A cook
cycle cannot take place until the door is firmly closed thereby
activating both interlock switches. The primary interlock sys-
tem consists of the door sensing switch and primary interlock
relay located on the control circuit board.
MONITOR SWITCH
The monitor switch is mounted on the upper position of latch
hook left. It is activated (the contacts opened) by the left latch
head while the door is closed. The switch is intended to render
the oven inoperative by means of blowing the monitor fuse
when the contacts of the primary interlock relay and second-
ary 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 door sensing and secondary
interlock switches 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
and the secondary interlock switch contacts close. (On
opening the door, each of these switches operate inversely.)
3. If the door is opened, and the primary interlock relay and

DESCRIPTION AND FUNCTION OF COMPONENTS

Latch hook left
Secondary
interlock switch
Latch hook right
Latch
head
Door
sensing switch
secondary interlock switch contacts fail to open, the
monitor fuse blows simultaneously with closing of the
monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN
MONITOR FUSE TEST THE DOOR SENSING
SWITCH, PRIMARY INTERLOCK RELAY,
SECONDARY INTERLOCK SWITCH AND
MONITOR
OPERATION. (REFER TO CHAPTER "TEST
PROCEDURE").
NOTE: MONITOR FUSE AND MONITOR SWITCH ARE
REPLACED AS AN ASSEMBLY.
THERMISTOR
The thermistor is a negative temperature coefficient type.
The temperature in the oven cavity is detected through the
resistance of the thermistor, and then the control unit
causes the heater relay to operate, thus the current to the
heating elements is turned ON/OFF. If the convection
cooking or some cooking modes which use the top / side
heating elements is started and the oven temperature does
ο
not rise above 100 F (37.8
oven after 10 minutes. In this case, the thermistor may be
opened.
MAGNETRON TEMPERATURE FUSE.
The temperature fuse located on the waveguide flange is
designed to prevent damage to the magnetron if an over
heated condition develops in the magnetron due to cooling
fan failure, obstructed air guide, dirty or blocked air intake,
etc.
Under normal operation, the temperature fuse remains
closed. However, when abnormally high temperatures are
reached within the magnetron, the temperature fuse will
ο
remain open at 302 F(150
down.
TOP HEATER THERMAL CUT-OUT
The thermal cut-out located on the thermal cover upper is
designed to prevent damage to the top heating element unit
if an over heated condition develops in the top heating
element unit due to convection fan failure, thermistor failure,
obstructed air ducts, dirty or blocked air intake, etc.
Under normal operation, the thermal cut-out remains closed.
However, when abnormally high temperature are reached
within the top heating element unit, the thermal cut-out will
ο ο
open at 338 F (170 C) causing the oven to shut down. When
the thermal cut-out has cooled, the thermal cut-out closes
ο ο
at 311 F(155 C).
SIDE HEATER THERMAL CUT-OUT
The thermal cut-out located on the thermal cover left is
designed to prevent damage to the side heating element
unit if an over heated condition develops in the top heating
element unit due to convection fan failure, thermistor failure,
obstructed air ducts, dirty or blocked air intake, etc.
Under normal operation, the thermal cut-out remains closed.
However, when abnormally high temperature are reached
11
E30SO75ESS
SWITCH FOR PROPER
ο
C), the control unit will stop the
ο
C) causing the oven to shut