20 | ENGLISH
The motor starts, but the motor protection switch triggers shortly after start-up
Cause
Solution
The thermal trigger on the motor protection switch is incorrectly
set
Have a specialist compare the setting of the trigger with the technical speci-
fications and adjust it if necessary
Increased power consumption due to major voltage drop
Have an electrician check the voltage on each phase and rewire if necessary
Excessive voltage differences on the three phases
Have a specialist inspect the connection and the switching system and correct
it as necessary
Incorrect direction of rotation
Swap the 2 phases from the mains supply
Impeller/propeller impeded by adhesive material, blockages and/or
solid matter, increased current consumption
Switch off the machine, secure it against being switched on again and free the
impeller/propeller or clean the suction port
The pumped fluid is too dense
Contact the manufacturer
The machine runs, but not at the stated operating levels
Cause
Solution
Intake blocked
Clean the intake, valve, suction port or intake strainer
Valve in the discharge line closed
Fully open the valve
Impeller/propeller blocked or obstructed
Switch off the machine, secure it against being switched on again and free the
impeller/ propeller
Incorrect direction of rotation
Replace 2 phases on the mains supply
Air in the system
Check the pipes, pressure shroud and/or pump unit, and bleed if necessary
Machine pumping against excessive pressure
Check the valve in the discharge line, if necessary open it completely
Signs of wear
Replace worn parts
Defective hose or piping
Replace defective parts
Inadmissible levels of gas in the pumped liquid
Contact the factory
Two-phase operation
Have a specialist inspect the connection and correct it as necessary
The machine does not run smoothly and is noisy
Cause
Solution
Machine is running in an impermissible operation
range
Check the operational data of the machine and correct if necessary and/or ad-
just the operating conditions
The suction port, strainer and/or impeller/propeller is blocked
Clean the suction port, strainer and/or impeller/Propeller
The impeller is blocked
Switch off the machine, secure it against being switched on again and free
the impeller
Inadmissible levels of gas in the pumped liquid
Contact the factory
Two-phase operation
Have a specialist inspect the connection and correct it as necessary
Incorrect direction of rotation
Replace 2 phases on the mains supply
Signs of wear
Replace worn parts
Defective motor bearing
Contact the factory
The machine is installed with mechanical strain
Check the installation, use rubber spacers if necessary
Mechanical shaft seal leaks, sealing chamber monitor reports fault and switches the machine off
Cause
Solution
Increased leakage when running in new mechanical shaft seals
Change the oil
Defective sealing chamber cables
Replace the moisture sensors
Mechanical shaft seal is defective
Replace the mechanical shaft seal after contacting the factory
Further steps for troubleshooting
If the items listed here do not help you rectify the fault,
contact our customer service. They can help you as fol-
lows:
• Telephone or written help from customer service
• On-site support from customer service
• Checking and repairing the machine at the factory
Note that you may be charged for some services provided
by our customer support. Customer service will provide
you with details on this.