Fault Finding - Grundfos TPE2 D Manual Del Usuario

29. Fault finding

DANGER
Electric shock
Death or serious personal injury
- Switch off the power supply to the motor and to the
signal relays. Wait at least 5 minutes before
starting any work on the motor. Make sure that the
power supply cannot be accidentally switched on.
DANGER
Magnetic field
Death or serious personal injury
- Do not handle the motor or rotor if you have a
pacemaker.
Fault
1. The motor does not run when started.
2. Motor alarm when the power supply is switched on.
3. Occasional motor alarm.
4. No motor alarm, but the pump does not run.
5. The pump performance is not constant.
6. The pump runs but delivers no water.
7. The pump runs backwards when switched off.*
8. Leakage in shaft seal.
9. Noise.
* In twin-head pump installations, the backup pump often rotates slowly.
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WARNING
Hazardous liquids
Death or serious personal injury
- If the pump is used for a liquid which is injurious to
health, it will be classified as contaminated. In
such cases, take proper precautions to avoid injury
to health when operating or working on the pump.
- Wear personal protection equipment.
CAUTION
Hot or cold liquids
Minor or moderate personal injury
- Wear personal protection equipment.
Cause and remedy
a) Supply failure.
b) The fuses are blown.
c) The motor is defective.
a) Supply failure.
b) The cable connection is loose or faulty.
c) The motor winding is defective.
d) The pump is mechanically blocked.
a) The supply voltage is periodically too low or too high.
b) The differential pressure across pump is too low.
a) Check the power supply.
b) Check fuses.
a) The pump inlet pressure is too low.
b) The inlet pipe or pump is partly blocked by impurities.
c) The pump draws in air.
a) The inlet pipe or pump is blocked by impurities.
b) The foot or check valve is blocked in closed position.
c) There is a leakage in the inlet pipe.
d) There is air in the inlet pipe or pump.
a) There is a leakage in the inlet pipe.
b) The foot or check valve is defective.
c) The foot or check valve is blocked in open or partly open position.
a) The shaft seal is defective.
a) The pump is cavitating.
b) The pump does not rotate freely (frictional resistance) because of
incorrect pump shaft position.
c) There is resonance in the installation.
d) There are foreign bodies in the pump.