8
Trouble-shooting
Pump is running but does not deliver
Pump delivers insufficient flow rate
Excessive current/power consumption
Insufficient discharge head
Vibrations and noise during pump operation
Table 24: Trouble-shooting
A B C D E Possible cause
Remedy
X
Pump delivers against an excessively high
discharge pressure.
Re-adjust to duty point.
X
Gate valve in the discharge line is not fully
open.
Fully open the gate valve.
X
X Pump is running in the off-design range (low
flow/overload).
Check the pump's operating data.
X
Pump or piping are not completely vented.
Vent by lifting the pump off the duckfoot bend
and lowering it again.
X
Pump intake clogged by deposits.
Clean the intake, pump components and non-
return valve.
X
X X Suction line or impeller clogged.
Remove deposits in the pump and/or piping.
X
X Dirt/fibres in the clearance between the
casing wall and impeller of a sluggish rotor.
Check that the impeller can be easily rotated.
Clean the impeller, if required.
X X X X Wear of internal parts
Replace worn parts by new ones.
X X
X
Defective riser (pipe and seal elements)
Replace defective riser pipes.
Replace seal elements.
X
X X Impermissible air or gas content in the fluid
handled
Contact KSB.
X System-induced vibrations
Contact KSB.
X X X X Wrong direction of rotation
Check the connection of the motor and
switchgear, if any.
X
Wrong supply voltage
Check the power cable.
Check the cable connections.
X
Motor is not running because of lack of
voltage.
Check the electrical installation.
Contact the energy supplier.
X
X
Motor winding or power cable are defective. Replace by new original KSB parts or contact
KSB.
X Defective rolling element bearing
Contact KSB.
X
Water level lowered too much during
operation
Check level control equipment.
X
The temperature switch monitoring the
winding has tripped because of excessive
temperature rise in the winding.
The motor will restart automatically once it has
cooled down.
X
Temperature limiter (explosion protection)
has tripped the pump as a result of the
permissible winding temperature being
exceeded.
Have cause determined and eliminated by
trained personnel.
X
Motor has been tripped by leakage monitor.
Have cause determined and eliminated by
trained personnel.
A
B
C
D
E
8 Trouble-shooting
50 of 66
Amarex® N
Goodnal STP ST041 Biological Treatment (KSB WAS PUMP 1 & 2 PU-0530-010 OM Instructions) Vendor Manual
Q-Pulse Id VM381
Active 29/10/2013
Page 52 of 76
