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the door switch. The start winding is now out of the
circuit and the run winding circuit is bypassing the start
switch, so the switch can be released without interrupt-
ing power to the run winding.
The drive motor performs two tasks in the dryer. A
pulley attached to one end of the motor shaft uses a
belt to drive the dryer drum. The blower wheel is at-
tached to the other end of the motor shaft and pulls the
air through the clothes and forces it out the exhaust
vent.
The Timer Motor Circuit:
When timer contacts B to C close, line 1 is applied to
one end of the timer motor winding. The other end of
the timer motor winding is connected to terminal TM of
the timer. Terminal TM is connected to neutral through
terminals P4 and P5 of the electronic moisture sensor
control, the start switch (when the motor is not running)
and through the centrifugal switch in the motor (when
the motor is running). Current flow through the timer
motor in the auto dry cycle, is controlled by the elec-
tronic moisture sensor control. The control circuit in
the electronic moisture sensor control is in series with
the timer motor. The electronic moisture sensor con-
trol 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 the bars. The electronic moisture
sensor control reads this and increases the resistance
between terminals P4 and P5. When resistance is in-
creased in a series circuit, the current flow in the cir-
cuit 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, prevent-
ing the timer from advancing. As the moisture is re-
moved from the clothes, the capacitance between the
bars increases. When the increase in capacitance
satisfies the electronic moisture control, the electronic
moisture control removes the resistance between ter-
minals P4 and P5, increasing the current flow through
the timer motor, causing the motor to advance.
Auto Dry Regular Cycle
When the dryer is connected to electrical power line 1
is connected to terminal B of the timer and one side of
the drum light. When the timer is set to the Auto Dry
cycle contacts B to C and B to A are closed. This
provides power at the start of the cycle to four circuits;
the drive motor circuit, timer motor circuit, electronic
moisture sensor control circuit and the heating circuit.
Drive Motor Circuit:
When contacts B to C are closed, line 1 is applied
through the thermal limiter (a non resettable fuse
mounted on the rear wall of the dryer) to terminal M4 of
the drive motor. Terminal M4 is connected in the motor
to one side of the thermal overload. (The thermal over-
load protects the motor from being damaged by over-
heating.) The other side of the thermal overload is con-
nected to one end of both the run winding and the start
winding of the drive motor. When the motor is not turn-
ing, the other end of the start winding is connected inter-
nally to terminal M5 of the motor through the NC contact
of the motor centrifugal switch. The other end of the run
winding is also connected internally to terminal M5.
When the motor is not turning the start winding and
the run winding are connected in parallel. Terminal
M5 of the motor is connected to the start switch, which
is connected to neutral through the door switch. When
the start switch is activated, with the dryer door closed,
line 1 to neutral voltage is applied across both the start
and run windings of the drive motor. With power ap-
plied to both the start and run windings, the motor starts
to turn.
When the speed of the motor reaches about 80% of its
normal run speed the contacts of the centrifugal switch
change from NC to NO, opening the circuit to the start
winding and connecting the run winding to motor ter-
minal M6. Terminal M6 is connected to neutral through
