Cause Remedy
• Retighten the anchor bolt nuts. Make sure that the
foundation is made according to the installation and
operating instructions.
8.8 Cavitation noise
Cause Remedy
Air leak in the inlet pipe or flange.
• Replace or repair the defective pipe section or
flange.
Cavitation; insufficient NPSH (depending on
installation).
1. Increase the net positive suction head by placing the
pump in a lower position.
2. Pressurise the inlet vessel.
The inlet pipe is not immersed deeply enough.
• Extend the inlet pipe so that the risk of sucking air is
eliminated.
Air or gases in the liquid.
• Remove the gas or air from the pumped liquid.
• See remedy in Cavitation; insufficient NPSH
(depending on installation) above.
The speed is too high.
• Check that the frequency of the power supply
corresponds to the frequency stated on the motor
nameplate.
8.9 The pump bearings are overheated
Cause Remedy
The shaft is bent due to damage.
• Check the deflection of the shaft. The total indicator
runout must not exceed 0.05 mm.
• Possibly replace the shaft.
Mechanical failure of bearing and/or impeller.
• Check the bearings and the impeller for damage.
• Replace the bearings or the impeller, if necessary.
Misalignment.
• Realign the pump and the motor.
The lubricating oil or grease is dirty or contaminated.
• Clean the bearings and bearing housings according
to the instructions and relubricate the bearings.
8.10 The pump operates for a short time and then stops
Cause Remedy
The pump is not primed, lack of priming liquid,
incomplete priming.
• Fill the pump and inlet pipe completely with pumped
liquid.
The suction lift or static lift is too high.
• Reduce the difference in height between the water
reservoir or water supply and the pump.
Air leak in the inlet pipe or flange.
• Replace or repair the defective pipe section or
flange.
Air leak in the stuffing box.
• Clean the flushing pipe. Replace the stuffing box
packing rings, if necessary.
42
English (GB)
To Next Page
Loading...
Need help?
General
