s
Product documentation 1D
3.8.
en
Rev. E, 10/13
page 33/42
4.5
Diagnostics of defects
4.5.1
Mechanical causes
Breakdown
Possible cause
Remedy precaution
Scr
at
chy
no
is
e
Bea
ri
n
g
s a
re
o
ver
h
ea
ted
Ex
ce
ssi
ve
tem
per
at
u
re o
f
g
en
er
at
or
Radi
al
v
ibr
ati
on
Axia
l v
ib
ra
tio
n
Ex
ce
ssi
ve
n
oi
se
•
Contact of rotor or shaft with
solid parts of machine appears
Find and eliminate cause
•
Limited access of air, excessive
amount of dust in winding,
dust in cooler ducts
Perform check of access of air,
pollution of winding, check cooler
•
Polluted or blocked air filter (if
it is equipped)
Filter exchange, if need to clean
•
Cooler function gets worse
(goes for design with water
cooler)
Clean cooler with regards to
operational instructions, check
amount of cooling medium, vent
cooler
•
Unbalance on rotor
Contact producer and require
balancing
•
Unbalance in coupling
Rebalancing
•
Transfer of vibration from
linked machine
Check of linked machine
•
•
Badly fixed generator in
foundation or changes in
foundation
Level machine, check foundation,
and tightening of generator
•
•
Resonance with foundation
Strengthen foundation
•
Lack of lubricant in bearing
Check amount of lubricant in bearing
•
Bearing is overloaded
Check tightening, levelling and
clamping of machine
•
Damaged or badly worn out
bearing
Perform exchange
Tab. 9 Mechanical causes