» Static unbalance of rotor
» Couple unbalance of rotor
» Radial misalignment across coupling
» Angular misalignment across coupling
» Loose mounting of structural & support components
» Looseness in rotating components
» Excessive clearances in bearings
» Various defects in rolling element bearings like race,
Stator shorts
– Soft foot
» Electric DC drive motors:
– SCR firing faults (Silicon Controlled Rectifier)
» Gear drive abnormalities like:
– Gear wear / abnormal meshing
– Gear / Pinion misalignment
– Gear / Pinion Excessive backlash
cage damages etc. – Gear / Pinion eccentricity
» Bearing damages due to electric current leak
» Lubrication issues in rolling element bearings
» Resonance
» Beat and Modulation phenomena
» Rubbing between rotating and static components.
» Abnormal acoustics issues due to the interaction of
– Gear / Pinion pitch line runout
– Gear / pinion tooth damage
» Belt / Chain drive abnormalities like:
– Belt / chain resonance
– Eccentric Drive / Driven pulley
» Conveyor Rollers: Various fault conditions like
Electromagnetic forces in motors, aerodynamics forces in – misalignment across both bearings of the Roller
Compressors/ Fans, hydrodynamics forces in Pumps etc. – Roller eccentricity
» Centrifugal pump abnormalities like: » Positive displacement Pumps (Gear / reciprocating etc.
– cavitation abnormalities like:
– Flow related issues due to improper operation – piping vibration due to excessive pressure pulses
– Impeller vane frequency due to excessive hydraulic – excessive noise and vibration due to hydraulic
forces pressure pulses
– Excessive mechanical loadings on pump connections
» Centrifugal Fans/Blowers/Compressor abnormalities like:
» Positive displacement compressors / blowers (Lobe /
Screw / Reciprocating etc.)
– Surge / Stall – Piping vibration due to excessive pressure pulses
– Flow related issues due to improper operation – excessive noise and vibration due to undesirable
– Blade pass frequency due to excessive aerodynamic aerodynamic interaction of static and rotating
forces components.
– Excessive Leakage across sealing arrangements
» Electrical Induction drive motors: Various fault
conditions like
» High vibration in equipment mounted on “Isolators”
due to malfunction / damage of the “Isolators”.
» Diesel Engines abnormalities like
– Air gap problem due to stator or rotor eccentricity – Bearing wear
– Cracked / loose rotor bars – Mounting wear and tear