Omega
39
Trouble--shooting Table
Pum
p
pressure
too
low
Pum
p
pressure
too
high
Flow
rate
too
high
Flow
rate
too
low
Pow
er
consum
ption
too
high
P
um
p
fa
ils
to
pum
p
liqui
d
af
ter
bei
ng
sw
itc
hed
on
Pum
p
ceases
to
pum
p
liquid
Pum
p
does
not
run
sm
oothly
(noise,
vibrations)
Inadm
issible
tem
perature
increase
at
pum
p
/
seal
casing
Bearing
tem
perature
too
high
Exessive
leakage
at
shaft
seal
D
rive
overloaded
Leakage
at
pum
p
Cause
Remedy
1
)
F
F
In star / delta operation
motor hangs at star sta-
ge
Check electrical connections
Check switchgear.
F
F
F
Inadmissible air or gas
content in liquid
Vent
Check integrity of suction pipe, seal if
necessary
F
F
F
F
F
Air drawn in at pump in-
let
Correct suction conditions
Reduce flow velocity at suction pipe en-
try
Increase suction head
Check integrity of suction pipe and seal,
if necessary
Replace defective pipes.
F
Cavitation (rattling noise) Correct suction conditions
Check mode of operation
Increase suction head
Install pump at a lower level
F
F
Foundation not rigid
enough
Check
Alter
F
F
F
F
F
Inadmissible parallel
operation
Re--adjust operating point
Alter pump characteristic H
1).
F
F
Shaft is out of true
Renew / Replace
F
F
F
F
Impeller rubs against ca-
sing components
Check rotor
Check impeller position
Check that the piping is connected wi-
thout transmitting any stresses or
strains.
1
) Consult KSB