Grundfos TPE2 Installation And Operating Instructions Manual page 77

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. a)
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.
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.
Check the power supply.
b) Check the fuses.
a) The pump inlet pressure is too low.
b) The inlet pipe or pump is partly is blocked by
impurities.
c) The pump draws in air.
a) The inlet pipe or pump is blocked by impurities.
b) The foot or non-return 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 non-return valve is defective.
c) The foot or non-return 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.
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