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The Timer Motor Circuit:
When timer contacts B to C close, line 1 is applied to
one side of the timer motor. The other side of the timer
motor is connected to terminal TM of the timer. Terminal
TM is connected to neutral through terminals P4 and P5
of the electronic moisture control, the push to start switch
(when the motor is not running) and through the centrifu-
gal switch in the motor (when the motor is running). Cur-
rent flow through the timer motor in the auto dry cycle is
controlled by the electronic moisture sensor control. The
control circuit in the electronic moisture sensor control
is in series with the timer motor. The electronic mois-
ture sensor control measures the capacitance between
the two sensor bars located in the vent cover.
When wet clothes are placed in the dryer the clothes
touch the sensor bars and the moisture lowers the ca-
pacitance between them. The electronic moisture sen-
sor control reads this and increases the resistance be-
tween terminals P4 and P5. When resistance is in-
creased in a series circuit, current flow in the circuit is
reduced. The increase in resistance inside the control
lowers the current flow through the timer motor below
the level needed to operate the motor, preventing the
timer from advancing. As the moisture is removed from
the clothes, the capacitance between the bars increases.
When the increase in capacitance satisfies the elec-
tronic moisture control, the electronic moisture control
removes the resistance between terminals P4 and P5,
increasing the current flow through the timer motor, caus-
ing the motor to advance.
Note:
In the auto regular cycle the timer motor can
run for 51 minutes. The cycle time can be 51
min plus the time current flow is being shunted
by the electronic moisture sensor control.
The Heat Circuit:
Timer contacts B to A connect line 1 to terminal 1 of
the fabric selector switch. The fabric selector switch
allows the dryer to be set to operate at High tempera-
ture, Medium temperature, Low temperature and Air
Fluff. In the Air Fluff setting the drum turns but the heater
does not operate. Whenever the fabric selector switch is
set to either High, Medium or Low, contact 1 is closed to
contact 2 and line 1 is applied to the control thermostat.
When the fabric selector switch is set to either Medium
or Low, power is applied to a small heater in the control
thermostat, and the contacts of the control thermostat
are cycled by a combination of heat from the heater and
the heat in the drum. When the fabric selector switch is
set to Medium, contacts 3 to 4 of the switch are closed
connecting the series circuit formed by a 560 Ohm re-
sistor and the small heater in the control thermostat to
neutral. When the fabric selector switch is set to Low,
contacts 4 to 5 of the switch are closed connecting the
small heater in the control thermostat to neutral. Since
more current flows through the thermostat heater in the
Low setting, the contacts cycle at a lower drum tem-
perature than Medium.
The control thermostat senses the temperature of the
air in the blower housing and controls the temperature
in the dryer by opening and closing the heating circuit.
When the temperature in the drum is below the cycle
temperature, the contacts of the control thermostat are
closed, connecting line 1 to the high limit thermostat.
The high limit thermostat is a safety device that pre-
vents the dryer from overheating, if the contacts of the
control thermostat fail closed. The contacts of the high
limit thermostat are normally closed and are set to open
at a temperature above the cycling temperature of the
control thermostat. From the output terminal of the
high limit thermostat, line 1 is connected to one side of
the holding coil of the gas valve, the secondary coil of
the gas valve and the sensor that is mounted on the
burner chamber.
The holding coil, secondary coil, booster coil, sensor
and igniter circuits interact with one another to assure
safe operation of the dryer gas burner.
Booster
Holding
Secondary
