KSB WKTR - Page 66

Fault Possible cause Remedial action
Pump back pressure is lower than
specified in the purchase order.
Re-adjust to duty point by means of the
valve in the discharge line.
In the case of persistent overloading, turn
down impeller(s), if possible.
Contact KSB Service.
Alignment of the pump set Check the alignment; re-align, if required.
Pump is warped. Check piping connections and secure
pump fastening.
Oil quality Check.
Rotor out of balance Clean the rotor.
Balance the rotor.
Defective bearing Replace.
Flow rate < specified value Flow rate Q
min
Cavitation noise in the pump
and/or piping
Damaged inlet pipe Check the inlet pipe.
Valve in the inlet pipe not completely
opened
Open the valve.
Pressure in the inlet tank is too low. Check the inlet tank and/or increase the
pressure.
NPSHavailable/NPSHrequired too low Check the inlet pipe.
Alter the inlet pipe.
Excessive speed of pressure fall Observe permissible speed of pressure fall.
Air ingress at the sealing element/
valves/shaft seal
Check the piping. Check shaft seal for
leakage.
Pump or piping are not completely
vented or primed.
Vent and/or prime.
Motor overloaded Wear of internal pump parts Replace defective parts.
Contact KSB Service.
Pump back pressure is lower than
specified in the purchase order.
Re-adjust to duty point by means of the
valve in the discharge line.
In the case of persistent overloading, turn
down impeller(s), if possible.
Contact KSB Service.
Density or viscosity of the fluid handled
higher than stated in the purchase
order
Contact KSB Service.
Speed is too high. Alter the impeller diameter.
Contact KSB Service.
Reduce the speed of the drive.
Pump is warped. Check pipeline connections and secure
pump fastening.
Supply voltage is too low. Check electrical connections.
Motor is running on two phases only. Replace defective fuses.
Check electrical connections.
8 Trouble-shooting
66 of 78
WKTR