Component Teardown and Testing
4-9
Thermal Cutout Removal
There are 4 different thermal cutouts in this unit with 4
different purposes.
1. Oven thermal cutout (flame sensor), on cavity top.
2. Bottom thermal cutout, on floor of control area.
3. Hood thermal cutout, inside control area on duct.
4. Magnetron thermal cutout, on magnetron.
Oven Thermal Cutout (Flame sensor)
The oven thermal cutout (Cavity TCO) is located on the
top side of oven cavity beside the exhaust duct with a
temperature rating of 320°F (160°C) / 140°F (60°C).
The cutout is tightly held to the top of the oven cavity by
duct-upper.
Replacement of Oven Thermal Cutout
1. Disconnect oven power.
2. Remove grille & outer panel.
3. Remove screws securing the duct upper.
4. Lift up the exhaust duct from the cavity.
5. Disconnect two wire leads. (See Figure 4-19)
Bottom Thermal Cutout
During a fire on the stove, the heat could be intense
enough to close the hood thermal cutout and force the
fan to run. While at moderate high temperatures we do
want the fan to run, during a fire it is advantageous to
NOT have the vent fan running. So if a fire were to start
on the stove top, the bottom thermal cutout would open
at 248°F (120°C) and remove all power to the microwave
oven. This cutout is not resetable.
To remove the Bottom Thermal Cutout:
1. Disconnect power and remove grille.
2. Remove control box assembly.
3. Remove two wire leads and extract one screw
securing cutout on base plate.
Figure 4-19. Oven Thermal Cutouts
Oven Thermal Cut-out
Hood Thermal Cutout
This cutout will protect the touch control from excessive
heat by turning the vent fan on at low speed. If the
surface units of the range are used for long periods of
time heat will build up and could damage the microwave
control. In order to prevent this a thermal cutout is
installed on the duct behind the control. This cutout
will close (158°F/70°C vent fan energized) and open
(104°F/40°C vent fan de-energized) depending on the
sensed temperature.
To remove the Hood Thermal Cutout:
1. Disconnect power and remove grille.
2. Remove control box assembly.
3. Remove two wire leads and extract one screw
securing cutout on duct. (See Figure 4-20)
Magnetron Thermal Cutout
The magnetron thermal cutout is located above the leads
to the magnetron. It is designed to prevent damage to
the magnetron if an overheated condition develops in the
tube caused by a cooling fan failure, obstructed air ducts,
dirty or blocked air intake. Under normal operation, the
magnetron thermal cutout remains closed. However,
when abnormally high temperatures are reached within
the magnetron, the magnetron thermal cutout will open at
320°F (160°C) causing the oven to shut down. After the
temperature drops to 140°F (60°C) it will reset and
cooking can be resumed.
Figure 4-20. Bottom and Hood Thermal Cutouts
Bottom Thermal Cut-out
If this cutout were to open, it would be difficult
to detect. The only time it functions is during an
overheat condition. It will be normally open when
checked with an ohmmeter.
Hood Thermal Cut-out
Содержание E30MH65GPSA
Страница 2: ......
Страница 32: ...Component Teardown and Testing 4 14 Notes ...
Страница 33: ...Wiring Diagrams 5 1 Wiring Diagram ...
Страница 34: ...Wiring Diagrams 5 2 Notes ...
Страница 38: ...Parts List 6 4 Notes ...