New Holland CX720 Repair Manual page 2204

POWER PRODUCTION - ENGINE COOLANT SYSTEM
Rotary screen Screen brush - Logical diagram (B.50.A.58.60 -
C.20.B.72)
The rotary screen brush is mounted inside the rotary screen, and is used to periodically remove dust, chaff and other
debris from the rotary screen to allow for good airflow through the hydraulic coolers and engine radiator. The rotary
screen brush is controlled by the combine electronics, and not by the operator.
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When the operator first turns the key to power up the electrical system, the electronics will ensure that the radiator
screen brush is retracted (Actuator extended). During operation in the field, the electronics will activate the actuator
to engage the brush (Brush In) whenever the operator engages the grain tank unloading system, as long as it has
been at least 10 minutes since the last occurance.
The brush motor is powered for 7 seconds to apply the brush to the surface of the screen, and is then reversed for
7 seconds to return the brush to the "Home" position (not contacting the rotary screen).
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