Inhoudsopgave
Advertenties
10. Faults, causes and remedies
WARNING! Risk of electric shock!
Danger from electrical current must be
eliminated.
Ensure that the pump's power supply is switched
off and secured against unauthorised reactiva-
tion before performing any work on the electric
system.
WARNING! Risk of burns!
In case of high water temperatures and high sys-
tem pressures, close the guard valves upstream
and downstream of the pump. First, allow pump
to cool
down.
Defaults
The pump is running but no
delivery
The pump is vibrating
No sufficient pressure for the
pump
The flow is irregular
In "Constant pressure" or "Variable pres-
sure" mode, the pump does not switch
off when the delivery rate is zero
If the fault cannot be resolved, please
contact Wilo customer
Installation and operating instructions – Wilo-Economy MHIE
Possible causes
The pump does not run quickly enough
The internal parts are obstructed by
particles
Suction pipe is obstructed
Air in suction pipe
Suction pressure is too low, it causes
generally cavitation noise
Pump is loosed on its foundation
Particles obstructing the pump
Difficult rotation of the pump
The motor speed is not high enough
The motor is defective
Bad filling of the pump
The drain-priming plug is not fully
tightened
The suction head (Ha) is not observed
The suction pipe has a lower diameter
than the one of the pump
The strainer and the suction pipe are
partially obstructed
In « Constant pressure » mode, the
pressure sensor is not adequate
The non-return valve is not tight
The non-return valve is not adequate
The tank has low capacity due to the
installation
service.
Remedies
Check the adequate adjustment of the
requirement (conformity to the setpoint)
Let dismantle the pump and clean it
Clean the pipe
Check tightness of the whole pipe up to
the pump and make it tight
Too high losses of load on suction or
suction head is too high (check the NPSH
of the pump installed and the installa-
tion)
Check and tighten completely the nuts
of the stud bolts
Have the pump dismantled and clean it
Check the pump turns freely without
abnormal sticking
Check if the setpoint is correctly
adjusted
Replace it
Open the venting device and vent until
there are no more air bubbles
Check it and screw it again
Study again the installation conditions
and the recommendations described in
this instruction
The suction pipe must have at least the
same diameter as the suction pump port
Remove and clean
Put a sensor with conforming pressure
scale and accuracy, see <chapter 4.4>
Clean it or change it
Replace it by an adequate non-return
valve, see <chapter 4.4>
Change it or add an other one on the
installation
English
59
Advertenties
Inhoudsopgave
