Service manual

38
Pressure Switch
The pressure switch is mounted to the center bar under
the top of the washer and controls the water level in the
washer.
The pressure switch is made up of a single pole double
throw switch, but only contacts 1 and 2 are used, that is
controlled by a bellow inside a sealed chamber. The
chamber is connect by a hose to the air bell located at
the bottom of the washer attached to the drain boot.
Electrical power is applied to the pressure switch
whenever the contacts of the door switch are closed. If
the water level is below 1/2 inch from the bottom of the
spin basket, contacts 1 to 2 of the pressure switch close
applying power to one side of the hot and cold solenoids
of the water valve and the bleach and softener solenoids
of the dispenser. The other side of the solenoids are
connected to neutral by a relay contacts on the control
board. When the cycle calls for water, depending on the
water temperature selected and the increment of the
cycle, the control board connects one, two or three of
the solenoid coils to neutral activating the water valve or
dispenser solenoids.
switch, switch actuator, locking fork, wax motor, and
spin lock arm.
Power is applied to one side of the coil whenever power
is applied to the washer. When a cycle is selected and
the start pad is touched the control board connects the
other side of the coil to neutral. The magnet field of the
coil pulls the locking fork down and tries to pull the
contacts of the door lock switch closed. If the washer
door is open a tab on the switch actuator prevents the
contacts from closing, (dr) will flash in the display and
the locking fork will not allow the door to be closed until
the stop pad is touched removing current from the coil.
When the washer door is closed the door strike pivots
the switch actuator out of the way allowing the magnetic
field of the coil to close the contacts of the door lock
switch and the locking fork locks the door. The wax
motor and spin lock arm are used to prevent the door
from being opened while the spin basket is still spinning.
The wax motor is electrically in parallel with the drain
pump. Power is applied to the wax motor when the
washer is in spin. When power is applied to the wax
motor it expands its piston within 30 to 40 seconds driving
the spin lock arm between the locking fork and the switch
actuator holding the locking fork down. When power is
removed from the wax motor it takes about 90 seconds
for the wax motor to cool down and retract the piston,
pulling the spin lock arm back away from the locking
fork. This provides enough time for the spin basket to
slow its rotation down to the wash speed before the door
could possibly be opened.
Contact
Wax Motor
Coil
Switch
Actuator
SPIN
LOCK
ARM
Locking
Fork
Pressure sw.