The Beach Boys hit song Good Vibrations was about picking-up on the good vibrations coming from another person. But there are no good vibrations coming from a centrifugal fan that has a problem. If the vibration problem is left uncorrected, it will eventually lead to fan failure. In the blog this week, I will provide some steps for trouble shooting a centrifugal vibration problem.
Trouble Shooting Steps
Here are the steps to take in trouble shooting a centrifugal fan vibration problem:
- Safety First: Your first step is to make sure that the fan is powered off and has been locked out/tagged out. This will prevent accidental start-up while you are working on it.
- Visual Inspection: Examine the fan for any obvious signs of damage or loose components. Check if any fasteners, bolts or screws are loose, especially the bolts on the motor mounts.
- Ductwork Inspection: Assess the condition of the fan’s ductwork or discharge system. If there are any obstructions, restrictions, or imbalance in the ductwork, it can cause the fan to vibrate.
- Examine Wheel: Look for any material build-up on the wheel which may cause the wheel to be unbalanced. After cleaning the wheel for any material build-up, now examine it for any excessive wear or loose blades.
- Belt Tension and Alignment: If the fan is belt driven, check the tension and alignment of the belts. Uneven wearing of the belt is a sign of miss alignment that could cause a vibration issue.
- Bearing Inspection: Inspect the bearings for damage, wear or lubrication issues. Excessive play, noise or heat in the bearing can lead to vibration.
- Review Fan Curve: Any changes in the process ductwork, such as adding a pick-up point or damper, will change the operating point of the fan. Fans operating in the unstable region of the fan curve will experience surges, stalling or vibration.
- Resonant Frequency: A fan operating at its resonant frequency will vibrate. The way to check for this is to use a VFD to slow down the fan until it no longer vibrates.
Conclusion
Don’t ignore a vibrating centrifugal fan. The longer the vibration problem goes unresolved the higher the potential for damage to the fan. If you need help trouble shooting your centrifugal fan vibration problem, contact a ventilation expert at Eldridge. We will find the problem and recommend solutions to get your centrifugal fan back in top operating condition.