VALVE AS-FLUID SAMPLING 8C3345 - Caterpillar

Generator Set:
3508 (S/N: CNF1-UP)
3508B (S/N: CNB1-UP; 4GM1-UP; 6PN1-UP)
3512B (S/N: CMC1-UP; BLF1-UP; ZAH1-UP)
3516 (S/N: CMD1-UP; CAL1-UP; ZAL1-UP; GZR1-UP)
3516B (S/N: FDN1-UP; GZT1-UP)
G3516 (S/N: 25Z1-UP)
Engine:
3508 (S/N: CNF1-UP; 23Z1-UP)
3508B (S/N: 4GM1-UP; 6PN1-UP)
3512 (S/N: 24Z1-UP)
3512B (S/N: 8RM1-UP; 6WN1-UP)
3516 (S/N: 25Z1-UP; 73Z1-UP)
3516B (S/N: 7RN1-UP; 1NW1-UP)
The 115-1783 Fan Spider As is designed to operate in the range of 726 to 780 rpm. Operation at speeds below 726 rpm compromise the structural integrity of the fan. A speed of approximately 690 rpm can create damaging resonant vibrations. Excessive vibrations can damage the fan.Follow these guidelines for maintaining the structural integrity of the 115-1783 Fan Spider As :
Perform maintenance for the fan drive belts according to the Operation and Maintenance Manual
Maintain the belt tension according to the Specifications manual or according to the 7N-9693 Tension Chart. Use the 144-0235 Belt Tension Gauge .
Verify the speed of the fan with the 9U-7400 Multitach Tool Gp .Note: Alternatively, consider upgrading to the 128-5631 Blower Fan As, which does not have an issue with resonant vibrations below the designed operating speed. The 128-5631 Blower Fan As does require approximately 50 additional horsepower.When a fan is replaced, new belts are required. Tension the new belts to approximately 801 N m (590 lb ft). After the fan has operated for one hour, adjust the tension of the belts to 378 N m (280 lb ft).