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b)
Overload motor.
c)
Low line voltage.
d)
Over tensioned belts.
e)
Misalign drive.
connection.
b)
Reduce system load.
c)
Check supplied voltage within motor
voltage range.
d)
Adjust belt tension.
e)
Re-align drive.
Motor overheats
a)
Overloaded motor.
b)
Motor Fan dirty/ damage.
a)
Reduce load or replace larger motor.
b)
Clean/ replace motor fan.
Low air volume after
start up
a)
Fan rotating in wrong direction.
b)
Air damper not properly set.
c)
Pressure drop by filter above
recommended level.
a)
Reverse any two phase connection at
motor terminal.
b)
Ensure system correctly balance & set.
c)
Change filters – (complete bank).
Excessive motor noise
a)
Motor mounting bolt loosen.
b)
Worn motor bearing.
a)
Tighten motor mounting bolt.
b)
Replace bearing and seals.
Excessive noise from
unit
a)
Worn fan or motor bearing.
b)
Fan impeller rubbing on inlet cone or
cover.
c)
Incorrect drive belts tension.
a)
Replace bearing and seals.
b)
Check clearance or remove for repair.
c)
Check tension.
Excessive vibration
a)
Fan impeller out of balance.
b)
Transport bracket not remove.
c)
Improper pulley alignment.
d)
Over-tensioned belts.
e)
Vibration isolator damaged.
f)
Motor shaft bend.
g)
Bad bearings.
h)
Loosen bearing hold down bolt
i)
Fan & motor section not evenly
supported on foundation.
j)
Fan assembly’s tolerance is out of
range.
a)
Consult manufacturer.
b)
Remove transport bracket.
c)
Check pulley alignment.
d)
Re-tension belts.
e)
Replace vibration isolator.
f)
Send the motor for repair.
g)
Replace bearing and seals.
h)
Tighten hold down bolt.
i)
Re-adjust and tighten.
j)
Conducts dynamic balancing.
Bearing excessively hot
a)
Over-tensioned belts.
b)
No lubricant.
c)
Over-lubricant.
d)
Misaligned bearing.
a)
Re-tension belts.
b)
Apply lubricant
c)
Purge and clean surface.
d)
Check & re-align shaft.
Water present in cooling
coil drain pan or overflow
a)
Drain trap clog.
b)
Incorrect hydraulic trapping.
a)
Clean & clear clog.
b)
Resize trap and check air break
arrangement.
Premature drive belts
failure
a)
Improper tension or alignment.
b)
Incorrect belt being fitted.
c)
Dirt or grease on belts.
d)
Belt rubbing.
e)
Worn sheaves.
a)
Check tension and alignment.
b)
Replace with full set.
c)
Clean belt & pulley, check for grease
leak.
d)
Remove obstruction.
e)
Replace sheaves.
Belt swelling or softening
a)
Excessive contamination by oil, certain
cutting fluids or rubber solvent.
a)
Replace with full set. Isolate the source
of contaminate.
Belt whipping during
running
a)
Incorrect tensioning.
a)
Re-tension belts.
Filter collapsing
a)
Filter block with dirt.
b)
Air velocity too high.
a)
Replace at advised dirty condition.
b)
Check unit running conditions.
Note: The table is intended as a diagnostic aid.