Fault Finding - Grundfos SMD Installation And Operating Instructions Manual

10. Fault finding

WARNING
Electric shock
Death or serious personal injury
‐
Before starting any work on mixers or
flowmakers, disconnect the motor from
the power supply or make sure that the
fuses are removed or the main switch
is switched off. Make sure that the
power supply cannot be switched on
unintentionally. Make sure that all rotat-
ing parts have stopped moving.
Fault Cause
No power supply, or supply failure.
Power supply cable is damaged.
Control system is damaged.
Propeller cannot rotate freely.
Mixer or flowmaker
Stator windings are damaged.
does not start.
Motor has cut out due to overheating.
Different phase voltages.
Overload relay is set too low or is dam-
aged.
Leakage sensor cut out mixer or flowmak-
er.
Humidity in the motor.
Stator windings are damaged.
Different phase voltages.
Mixer or flowmaker Overload relay is set too low or is dam-
starts, but stops im- aged.
mediately.
Leakage sensor has cut out mixer or flow-
maker.
Humidity in the motor.
Propeller rotates in the wrong direction.
Mixer or flowmaker runs on two phases.
No or inadequate cir-
culation produced
even if the motor is
Internal parts are worn.
running.
Propeller blades are dirty or damaged.
Mixer or flowmaker
Internal parts are worn.
runs unevenly and is
All regulations applying to mixers or flow-
makers installed in potentially explosive
environments must be observed.
Make sure that no work is carried out in
potentially explosive environment.
Keep a service log.
Remedy
• Re-establish the power supply. Start the
mixer or flowmaker manually.
• Contact an authorised service work-
shop.
Contact an authorised service workshop.
Contact an authorised service workshop.
Clean the propeller blades and make sure
that the propeller can rotate freely.
Contact Grundfos.
Wait until the motor is cooled, and try to re-
start the mixer or flowmaker.
Contact an authorised service workshop.
Check the overload relay. Set the relay to
the rated current.
Contact Grundfos.
Contact Grundfos.
Contact Grundfos.
Contact an authorised service workshop.
Check the overload relay. Set the relay to
the rated current.
Contact Grundfos.
Contact Grundfos.
Interchange two phases of the main supply.
• Check the electrical connections.
• Replace damaged fuses.
• Call an electrician.
Contact Grundfos.
Clean the blades and inspect them for any
wear. In case the propeller blades are worn
or damaged, contact Grundfos.
Contact Grundfos.
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