Bottom Thermal Cutout; Magnetron Thermal Cutout - Samsung SMH7178STE Service Manual

5-9-3 Bottom Thermal Cutout

This cutout will protect the touch control from exces-
sive 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 micro-
wave 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
temperatures it sense.
To Remove hood Thermal Cutout :
1. Disconnect power and remove grille.
2. Remove control box assembly.
3. Remove two wire leads and unscrew one screw
capturing cutout on base plate.
NOTE : It 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.

5-9-4 Magnetron Thermal Cutout

THIS COMPONENT REQUIRE REMOVAL OF
MICROWAVE OVEN FROM INSTALLATION FOR
SERVICING.
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 temperature we
do want it to run, however during a fire it is advantage-
ous 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 designed to not be
resetable.
To Remove Bottom Thermal Cutout :
1. Disconnect power and remove grille.
2. Remove control box assembly.
3. Remove two wire leads and unscrews one screw
capturing cutout on base plate.
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HOOD THERMAL CUTOUT
BOTTOM THERMAL CUTOUT
HOOD THERMAL CUTOUT
BOTTOM THERMAL CUTOUT