Fault Finding The Product - Grundfos SMD Series Installation And Operating Instructions Manual

11. Fault finding the product

Before starting work on the mixer or flowmaker,
– make sure that the fuses have been removed or
the main switch has been switched off
– make sure that the power supply cannot
accidentally be switched on
– make sure all rotating parts have stopped
moving.
Fault Cause
1. The mixer or a) No power supply, or supply failure.
flowmaker does not
b) The power cable is faulty.
start.
c) The control system is faulty.
d) The propeller is not free to rotate.
e) The stator windings are faulty.
f)
g) Different phase voltages.
h) The overload relay is set too low or is faulty.
i)
j)
2. The mixer or a) The stator windings are faulty.
flowmaker starts but
b) Different phase voltages.
stops immediately.
c) The overload relay is set too low or is faulty.
d) The leakage sensor has cut out the mixer or
e) Humidity in the motor.
3. No or inadequate a) The propeller rotates in the wrong direction.
circulation produced
b) The the mixer or flowmaker runs on two phases.
even if the motor is
running.
c) The internal parts are worn.
d) The propeller blades are dirty or damaged.
4. The mixer or a) The internal parts are worn.
flowmaker runs
b) The propeller blades are dirty or damaged.
unevenly and is
noisy.
c) The motor or gearbox roller bearings are faulty.
d) Oscillations and resonance caused by the
The motor has cut out because of overheating.
The leakage sensor has cut out the mixer or
flowmaker.
Humidity in the motor.
flowmaker.
installation.
All regulations applying to mixers installed in
potentially explosive environments must be
observed.
FM
Make sure that no work is carried out in potentially
explosive environments.
Keep a service log.
Remedy
Call an electrician.
Call an electrician.
Call an electrician.
Clean the propeller blades, and check manually that
the propeller can rotate freely.
Contact Grundfos.
Wait until the motor has cooled, and try to restart the
mixer or flowmaker.
Call an electrician.
Check the overload relay. Set the relay to the rated
current.
See section Overload relays
Contact Grundfos.
Contact Grundfos.
Contact Grundfos.
Call an electrician.
Check the overload relay. Set the relay to the rated
current.
See section Overload relays
Contact Grundfos.
Contact Grundfos.
Interchange two phases of the mains supply.
• Check electrical connections.
• Replace faulty fuses.
• Call an electrician.
Contact Grundfos.
Clean the blades, and inspect for any wear. If the
propeller blades are worn or damaged, contact
Grundfos.
Contact Grundfos.
Clean the blades, and inspect for any wear. If the
propeller blades are worn or damaged, contact
Grundfos.
Contact Grundfos.
Check the installation design.
on page 16.
on page 16.
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