GE EWA4600G0 Technical Service Manual page 8

Mode Shifter Operation - Agitation
The mode shifter is controlled by the motor inverter circuit. When the washer starts the agitation cycle,
the inverter energizes the mode shifter coil. The magnetic field of the coil lifts the mode shifter cam,
disengaging it from the drive pulley. Without the cam engaged, the drive pulley rotates only the
agitator shaft.
At the beginning of the agitation cycle, the inverter energizes the mode shifter coil with
MODE SHIFTER
135 VDC (PWM) for approximately 18 seconds. This high voltage pulls the mode shifter
AGITATE
PROGRAM
cam up from the drive pulley. During this time, the motor also rotates clockwise and
RUNS
(18 SEC)
counterclockwise in short strokes to ensure the mode shifter cam has been released from
the drive pulley. This operation is called the Mode Shifter Agitate Program. It is normal to
hear metal-to-metal "clunking" sounds during this time as the cam and drive pulley
disengage. The washer runs this program when the agitation cycle first starts, when
power is restored if lost during agitation or when the user restarts the washer if paused.
Once the Mode Shifter Agitate Program has completed (18 seconds), agitation begins. During agitation,
the inverter continues to supply 30 VDC (PWM) to the mode shifter coil. This voltage is sufficient to hold
the mode shifter cam away from the drive pulley throughout the remainder of the agitation cycle.
The inverter motor controls the speed of agitation. The agitator stroke rate is approximately 30 strokes
per minute. This rate is the same for all cycles. The speed of the motor controls the arc. At fast speed,
the arc is approximately 360 degrees. At slower speeds, the arc is substantially less. It is the distance of
the arc that determines normal or gentle wash cycles.
Mode Shifter Operation - Spin
At the beginning of the spin cycle, the inverter runs a short sequence (approximately 30
seconds) to make certain the mode shifter cam is engaged with the drive pulley. The
MODE SHIFTER
SPIN
inverter does not supply voltage to the mode shifter coil during this sequence. Since the
PROGRAM RUNS
(30 SEC
coil is not energized, the spring loaded cam drops down into the teeth of the drive pulley.
During this time, the motor also rotates clockwise and counterclockwise in short strokes to
ensure the cam has engaged with the drive pulley. This 30 second operation is called the
Mode Shifter Spin Program. It is normal to hear metal-to-metal "clunking" sounds during
this time as the cam and drive pulley engage.
Notes:
If the washer is paused while in agitation, it is NORMAL to hear sounds for an additional 30 seconds as
the inverter control runs the Mode Shifter Spin Program to de-energize the coil and enter a pause state.
If the washer is in agitation and power is lost, the inverter control will run the Mode Shifter Agitate
Program when power is restored.
If the washer is in spin and power is lost, the inverter control will run the Mode Shifter Spin Program
when power is restored.
To help prevent out-of-balance conditions, the last 10 seconds of agitation on certain cycles will be
short, fast strokes to help redistribute the clothes load prior to entering the spin cycle.
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