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| Illustration 1 | g03398995 |
Hydraulic schematic for the hydraulic fan cooling circuit (1) Swivel (2) Rear back pressure manifold (3) Front back pressure manifold (4) Fan directional solenoid (5) Fan motor (6) Hydraulic oil cooler (7) Fan speed solenoid (8) Check valve (9) Fan pump (10) Hydraulic oil tank | |
The IQAN system uses a temperature sensor to monitor the hydraulic oil. When the temperature of the hydraulic fluid exceeds the setting programmed into the monitoring software, the cooling fan is activated. Hydraulic oil is delivered to fan motor (5) by fan pump (9) . Fan pump (9) is connected to the engine making the output of the pump less variable than the requirements of cooling fan motor (5) .
The fan is controlled by electrical current from the IQAN monitoring system. As the temperature of the fluid increases, the speed of the fan increases proportionally by the PWM signal that is sent to fan speed solenoid (7) . Fan speed solenoid (7) is located between fan pump (9) and fan directional solenoid (4) . If the temperature of the hydraulic fluid exceeds the maximum level determined by the IQAN software, the operator monitor will alert the machine operator.
Periodically, the IQAN system instructs fan directional solenoid (4) to shift the spool of the solenoid changing the direction of the fan. This change in fan direction, allows dirt and debris to be cleared from hydraulic oil cooler (6) .