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 27: 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 whether the impeller can be easily
rotated.
Clean the impeller, if required.
X X X X Wear of internal pump 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 mains power supply.
Check the connection of the power cables.
X
Motor is not running because of lack of
voltage.
Check the electrical installations.
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
X
In case of star-delta configuration: motor
running in star configuration only.
Check star-delta contactor.
X
Water level lowered too much during
operation.
Check the level control.
X
The temperature switch monitoring the
winding has tripped because of excessive
temperature rise in the winding.
The motor will restart automatically once the
winding has cooled down.
X
Thermistor tripping unit with manual reset
for temperature limiter (explosion protection)
has tripped the pump as a result of the
permissible winding temperature being
exceeded.
Assign qualified and trained personnel to
determine and remedy the cause of failure.
X
The leakage monitoring system of the motor
has tripped.
Assign qualified and trained personnel to
determine and remedy the cause of failure.
X
The mechanical seal monitoring system has
tripped.
Assign qualified and trained personnel to
determine and remedy the cause of failure.
X
The bearing temperature monitoring system
has tripped
Assign qualified and trained personnel to
determine and remedy the cause of failure.
A
B
C
D
E
8 Trouble-shooting
54 of 74
Amarex KRT
Goodnal STP ST041 Sewage Delivery (Amarex KRT Submersible Motor Pump) Vendor Manual
Q-Pulse Id VM362
Active 29/10/2013
Page 56 of 96
