Analysis of the five main types of faults in centrifugal fans

1. The bearing housing is vibrating violently.

The centrifugal fan shaft and motor shaft are not aligned, and the coupling is tilted.
The housing or inlet is rubbing against the impeller.
The foundation lacks sufficient stiffness or is unstable.
The impeller rivets are loose or the impeller disc is deformed.
The impeller shaft disc is loose from the shaft, and the coupling bolts are loose.
Loose connection bolts between the housing and the support, the bearing housing and the support, the bearing housing cover and the exhaust fan base, etc.
Improper installation of the inlet and outlet pipes of the centrifugal fan, causing vibration.
Unbalanced rotor.
Too narrow ductwork and excessive air velocity.

2. Excessive bearing temperature rise.

Severe vibration of the bearing housing.
Poor quality lubricating grease, deterioration, excessive filling, or contamination with dust, sand, dirt, and other impurities.
Excessive or insufficient tightness of the connecting bolts between the bearing housing cover and base.
Misalignment of the shaft and rolling bearing assembly, with the front and rear bearings not concentric.
Rolling bearing damage.

3. Excessive motor current and excessive temperature rise.

The gate or throttle valve in the intake duct is not fully closed during startup.
Flow exceeds the specified value or there is air leakage in the duct.
The gas transported by the centrifugal fan contains viscous substances or the ambient temperature is too low, resulting in excessive gas density.
The motor input voltage is too low or there is a single-phase power failure in the power supply room.
Misaligned coupling, overly tight belt, or uneven clearance.
Severe vibration from the bearing housing.
Deterioration in the operating condition of parallel fans or fan malfunction.

4. Belt slipping.

The corresponding grooves of the two pulleys are not aligned.

5. Belt jumping.

The distance between the two pulleys is too close, or the belt is too long.