Greenheck Vane Axial Fans (452954) - Manual (Page 10)

Problem Cause Corrective Action
Motor vibrates after
corrections have been
made
Motor misaligned Realign.
Weak support Strengthen base.
Coupling out of balance Balance coupling.
Driven equipment
unbalanced
Rebalance driven equipment.
Defective ball bearing Replace bearing.
Bearings not in line Line up properly.
Balancing weights shifted Rebalance motor.
Polyphase motor running
single phase
Check for open circuit.
Excessive end play Adjust bearing or add washer.
Unbalanced line
current on polyphase
motors during normal
operation
Unequal terminal volts Check leads and connections.
Single phase operation Check for open contacts.
Scraping noise
Fan rubbing air shield Remove interference.
Fan striking insulation Clear fan.
Loose on bedplate Tighten holding bolts.
Noisy operation
Airgap not uniform Check and correct bracket fits or bearing.
Impeller unbalanced Rebalance.
Hot bearings general
Bent or sprung shaft Straighten or reshaft.
Excessive belt pull Decrease belt tension.
Pulleys too far away Move pulley closer to motor bearing.
Pulley diameter too small Use larger pulleys.
Misalignment Correct by realignment of drive.
Hot ball bearings
Insufficient grease Maintain proper quantity of grease in bearing.
Deterioration of grease or
lubricant contaminated Remove old grease, wash bearings thoroughly in kerosene
and replace with new grease.
Excess lubricant
Reduce quantity of grease, bearing should not be more
than 1/2 filled.
Overloaded bearing Check alignment, side and end thrust.
Broken ball or rough races Replace bearing, first clean housing thoroughly.
Troubleshooting
10 Vane Axial Fans
®