27
Ausgabe
issue
B / 11.09.2007
Dokument
document
OM.REC.01e
Blatt
sheet
1 (2)
8
Malfunctions, causes, rectification
Refer to technical data (chapter 3.) for application range of the pump.
Malfunction
Causes
Rectification
Pump is
not
sucking
Pum
p
pum
ping
u
n
e
v
e
n
ly
Co
nv
ey
ing
c
a
p
a
cit
y
is
no
t
ac
hie
v
e
d
Pre
s
su
re
h
ead
is
no
t
reache
d
Pum
p
doe
s n
o
t
st
ar
t
u
p
Pum
p
se
ize
d
/
p
u
mp
d
oes no
t pu
mp
Pump is
loud when
running
Mo
to
r ge
ts
too
h
o
t
Pre
m
atu
re st
ator
we
ar
Sh
af
t se
al
is le
a
ky
X
X
X Static friction between sta-
tor/rotor too great.
Apply lubricant (liquid soap)
between stator and rotor.
X
Incorrect direction of rota-
tion.
Check direction of rotation
and swap over motor con-
nections if necessary.
X X X
X X
Suction pipe or shaft seal
leaking.
Eliminate leaks.
X X X
X
Suction head too great.
Check the suction head, if
necessary increase pipe
cross section on suction
pipe and use a larger filter,
open suction-side valve
fully.
X X X
Viscosity of conveying
product too great.
Check/adapt (data sheet).
X
X
X
Pump rotation speed
incorrect.
Correct rotation speed (data
sheet).
X X
Avoid air bubbles in the
conveying product.
X
X X
X X
Pressure head too great.
Check pressure head with
pressure gauge, reduce
pressure head by using
larger pressure pipe
crossed section or shorten-
ing the pressure pipe.
X X X
X
X
Pump running partially/
completely dry.
Check there is adequate
conveying product avail-
able on the suction side.
Dry running protection DRP.
X X
Check coupling.
If necessary, move pump in
relation to drive, check wear
on coupling gear, re-adjust
coupling if necessary.
X
X
Rotation speed too low.
Increase rotation speed for
low-viscosity media/large
suction volume.
