Wilo Economy - Page 39

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Installation and operating instructions Wilo-DEA 33
Pump(s) not stable and/or make unusual
noises
Inlet pressure fluctuates sharply Check inlet pressure, if necessary take
measures to stabilise supply pressure
(e.g. pressure reducer)
Inlet pipe blocked or shut off Check inlet pipe, if necessary remove
blockage or open check valve
Nominal diameter of inlet pipe too small Check the inlet pipe, increase the cross-
section for the inlet pipe if necessary
Inlet pipe incorrectly installed Check inlet pipe, if necessary change
pipe guide
Air in inlet Check, if necessary seal pipe. Vent
pumps
Air in the pump Vent pump, check suction line for leaks
and seal if necessary
Impellers blocked Check pump, if necessary replace or have
repaired
Volume flow too large Check pump data and default values and
correct if necessary
Direction of motor rotation false Check direction of rotation and correct
by changing over phases if necessary
Mains voltage: a phase is missing Inspect fuses, cables and connections
Pump not adequately secured to base
frame
Check fixation, tighten screws if neces-
sary
Bearing damage Check pump/motor, replace if necessary
or have repaired
Motor or pump become too warm
Air in inlet Check, if necessary seal pipe. Vent
pumps
Gate valve in system closed or not suffi-
ciently open
Check, open the check valve completely
if necessary
Impellers blocked Check pump, if necessary replace or have
repaired
Non-return valve blocked Check, if necessary remove blockage or
replace non-return valve
Check valve closed at pressure sensor Inspect, open check valve if necessary
Switch-off point set too high Check setting and correct if necessary
Bearing damage Check pump/motor, replace if necessary
or have repaired
Turn-to-turn fault in motor Check, if necessary replace motor or
have repaired
Mains voltage: a phase is missing Inspect fuses, cables and connections
Current consumption too high Non-return valve leaking Check, if necessary replace seal or
replace non-return valve
Volume flow too large Check pump data and default values and
correct if necessary
Turn-to-turn fault in motor Check, if necessary replace motor or
have repaired
Mains voltage: a phase is missing Inspect fuses, cables and connections
Motor protection switch triggers
Non-return valve defective Check, if necessary replace non-return
valve
Volume flow too large Check pump data and default values and
correct if necessary
Contactor defective Check and replace if necessary
Turn-to-turn fault in motor Check, if necessary replace motor or
have repaired
Mains voltage: a phase is missing Inspect fuses, cables and connections
Fault Cause Remedies