Wilo Economy Notice De Montage Et De Mise En Service page 38

English
Fault
Pump(s) do not switch off
Switching frequency too high
or fluttering
32
Cause
Inlet pressure fluctuates sharply
Inlet pipe blocked or shut off
Nominal diameter of inlet pipe too small Check the inlet pipe, increase the cross-
Inlet pipe incorrectly installed
Air in inlet
Impellers blocked
Non-return valve leaking
Non-return valve blocked
Gate valve in system closed or not suffi-
ciently open
Volume flow too large
Check valve closed at pressure sensor
Switch-off pressure set too high
Direction of motor rotation false
Inlet pressure fluctuates sharply
Inlet pipe blocked or shut off
Nominal diameter of inlet pipe too small Check the inlet pipe, increase the cross-
Inlet pipe incorrectly installed
Check valve closed at pressure sensor
Supply pressure at diaphragm pressure
vessel incorrect
Valve on diaphragm pressure vessel
closed
Set switching difference too small
Remedies
Check inlet pressure, if necessary take
measures to stabilise supply pressure
(e.g. pressure reducer)
Check inlet pipe, if necessary remove
blockage or open check valve
section for the inlet pipe if necessary
Check inlet pipe, if necessary change
pipe guide
Check, if necessary seal pipe. Vent
pumps
Check pump, if necessary replace or send
for repair
Check, if necessary replace seal or
replace non-return valve
Check, if necessary remove blockage or
replace non-return valve
Check, open the check valve completely
if necessary
Check pump data and default values and
correct if necessary
Inspect, open check valve if necessary
Check setting and correct if necessary
Check the direction of rotation and cor-
rect by changing over the phases if nec-
essary
Check inlet pressure, if necessary take
measures to stabilise supply pressure
(e.g. pressure reducer)
Check inlet pipe, if necessary remove
blockage or open check valve
section for the inlet pipe if necessary
Check inlet pipe, if necessary change
pipe guide
Inspect, open check valve if necessary
Check supply pressure and correct if
necessary
Check valve and open if necessary
Check setting and correct if necessary
WILO SE 07/2010