PLATE AS 1359248 - Caterpillar

General Information
In this system, the pitch of the fan blades is controlled by a timer and a solenoid valve. The timer will initiate purges at preset intervals. This timer is also capable of receiving signals from a manual purge switch. When the manual purge switch is pressed of the preset time interval has passed, the timer sends a signal to the solenoid valve. This solenoid valve directs hydraulic oil to the hydraulic connectors on the fan assembly. The pressure from the hydraulic oil allows the fan to change the pitch of the blades. The system does not use temperature sensors or position sensors.System Operation
The fan will be placed in the standard operating position when the machine is started. The timer will initiate purges at preset intervals for a preset duration. The manual purge switch may be pressed at any time in order to initiate a purge cycle. When the manual purge switch is pressed and released, the fan will do a full purge cycle and the timer will be reset. After a purge has been initiated by the manual purge switch, the next purge will occur after a complete interval has passed. The pressure from the hydraulic oil allows the fan blades to be placed in one of the following positions: PUSH -Air is drawn from the engine compartment and out through the radiator. PULL -Air is drawn through the radiator into the engine compartment.A hydraulic solenoid valve is used in the system.