Wilo MVIE Série Notice De Montage Et De Mise En Service page 20

ENGLISH
Other defects, not detected by the speed variator, due to the
pump.
Before any operation, SWITCH OFF the pump(s).
If the liquid is toxic, corrosive or dangerous for human being,
WILO or the qualified person in charge of the repairing must
be informed. In this case, clean the pump to ensure a complete
safety to the repairing man.
DEFAULTS
8.4 THE PUMP TURNS
BUT NO DELIVERY
8.5 THE PUMP IS VIBRATING
8.6 NO SUFFICIENT
PRESSURE FOR THE
PUMP
8.7 THE FLOW IS
IRREGULAR
If the fault cannot be remedied, please contact your plumbing and heating specialist or
your nearest WILO customer services or representative.
Subject to technical alterations!
20
CAUSES
a) The pump does not run quickly enough :
b) The internal parts are obstructed
by particles :
c) Suction pipe are obstructed :
d) Air in suction piping :
e) Suction pressure is too low,
it causes generally
cavitation noise :
a) Loose on its foundation :
b) Particles obstrucing the pump :
c) Difficult rotation of the pump :
a) The motor speed is not high enough :
b) The motor is defective :
c) Bad filling of the pump :
d) The drain-priming plug is not
fully tightened :
a) The suction head (HA) is not
respected :
b) The suction pipe has a lower
diameter than the one of the pump :
c) The strainer and the suction
pipe are partially obstructed :
REMEDIES
a) Check the adequate adjustment of the po-
tentiometer (conformity to the required points).
b) Let dismantle the pump and clean it.
c) Clean all the pipes.
d) Check tightness of the whole pipe up to be
pump an make it tight.
e) Too high losses of load on suction or suction
head is too high.
(Check the NPSH of the pump installed and
of the installation).
a) Check and tighten completely the nuts of
the stud bolts.
b) Have the pump dismantled and clean it.
c) Check the pump turns freely without
abnormal sticking.
a) Check the reference is correctly adjusted
(conformity of the reference points).
b) Replace Motor-converter.
c) Open the venting device and venty until
there are no more air bubbles.
d) Check it and screw it again.
a) Study again the installation conditions and the
recommendations described in this manual.
b) The suction pipe must have the same
diameter as the suction pump port.
c) Remove and clean.