Wilo ISAR MODH1 Series Installation And Operating Instructions Manual page 14

Fault
Current consumption too high
Motor protection switch triggers
Pump(s) produce(s) no or too little power
Pump(s) produce(s) no or too little power
Dry-running protection switches off
although water is present
Dry-running protection does not switch
off, although water low
You can find information on pump or control device faults not dealt with here in the attached documentation for the components concerned.
If the operating fault cannot be resolved, contact a Wilo customer service department.
Cause
Non-return valve leaking
Flow rate too high
Turn-to-turn fault in the motor
Mains voltage: a phase is missing
Non-return valve defective
Flow rate too high
Contactor defective
Turn-to-turn fault in the motor
Mains voltage: a phase is missing
Major fluctuations of the inlet pressure
Inlet pipe clogged or shut off
Nominal diameter of the inlet pipe too small
Inlet pipe installed incorrectly
Air in the inlet
Impellers clogged
Non-return valve leaking
Non-return valve clogged
Gate valve in the system closed or not
sufficiently open
Low-water level switch has been
triggered
Incorrect direction of rotation of the
motors
Turn-to-turn fault in the motor
Major fluctuations of the inlet pressure
Nominal diameter of the inlet pipe too
small
Inlet pipe installed incorrectly
Electrodes connected incorrectly or
supply pressure switch set incorrectly
Low water switch defective
Electrodes connected incorrectly or pressure
for low water cut-out switch set incorrectly
Low water switch defective
Remedy
Check and replace the seal or non-return
valve if necessary
Check the pump data and default values and
correct if necessary
Check, if necessary replace motor or have it
repaired
Check the fuses, cables and connections
Check and replace the non-return valve if
necessary
Check the pump data and default values and
correct if necessary
Check it and replace it if necessary
Check, if necessary replace motor or have it
repaired
Check the fuses, cables and connections
Check the inlet pressure and take measures to
stabilise the inlet pressure if necessary
(e.g. pressure reducers)
Check the inlet pipe and remove the clogging
or open the shut-off valve if
necessary
Check the inlet pipe and increase the cross-
section of the inlet pipe if necessary
Check the inlet pipe and change the pipe
routing if necessary
Check and shut off the piping and vent the
pumps if necessary
Check the pump and replace it or have it
repaired if necessary
Check and replace the seal or non-return
valve if necessary
Check and remove the clogging or replace
the non-return valve if necessary
Check and open the shut-off valve
completely if necessary
Check the inlet pressure and the level in the
break tank
Check direction of rotation and correct by
changing over phases if necessary
Check, if necessary replace motor or have it
repaired
Check the inlet pressure and take measures to
stabilise the inlet pressure if necessary
(e.g. pressure reducers)
Check the inlet pipe and increase the cross-
section of the inlet pipe if necessary
Check the inlet pipe and change the pipe
routing if necessary
Check the pump data and default values and
correct if necessary
Check and, if necessary, replace the low
water switch
Check installation and setting and correct as
required
Check and, if necessary, replace the low
water switch
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