42
A.0500.551 – IM-TGMAG/02.00 EN (02/2008)
Symptom Cause Remedy
Not enough capacity Liquid leaking back to suction over the
magnetic coupling
21 • Check/correct assembly of the circulation pump
arrangement
• Check/adjust axial clearance of the circulation
pump and rear face of the rotor
Pump too noisy
Vibrations
Pump speed too high 22 • Reduce pump speed.
If necessary, install a larger pump.
Cavitation 23 • Reduce difference between pump and suction
tank level.
• Increase suction pipe diameter.
• Reduce length and simplify suction pipe (use as
few elbows and other fittings as possible).
Also see section 3.18 Installation.
Backpressure too high 24 • Increase pipe diameter.
• Reduce working pressure.
• Check accessories (filter, heat exchanger, etc.).
Coupling misalignment 25 • Check and correct alignment.
Also see section 3.18 Installation.
Vibration of base plate or pipings 26 • Make base plate heavier and/or affix baseplate/
pipework better.
Ball bearings damaged or worn 27 • Replace ball bearings.
Un-balance of the outer magnetic rotor 28 • Check/correct assembly of the outer magnetic
rotor on the pump shaft
• Check correct tightening of bolts, secure bolts
against loosening.
Pump consumes
too much power or
becomes hot
Pump speed too high 29 • Reduce pump speed.
If necesary, install a larger pump.
Coupling misalignment 30 • Check and correct alignment.
Also see section 3.18 Installation.
Viscosity too high 31 • Increase axial clearance.
See section 3.21 Maintenance instructions.
• Heat pump.
• Reduce pump speed.
• Increase discharge pipe diameter.
Excessive friction losses inside rotor shaft
/ bearing arrangement
32 • Check/correct axial clearance of circulation pump
and rear face of the rotor
• Check axial clearance of the plain bearing ar-
rangement replace bearing if necessary
Rapid wear Back pressure too high 33 • Increase pipe diameter.
• Reduce working pressure.
• Check accessories (filter, heat exchanger, etc.)
Solid matter in liquid 34 • Filter liquid.
Pump runs dry 35 • Correct liquid supply.
• Provide liquid level switch or dry running protec-
tion.
• Heat up liquid.
• Stop or reduce air sucking.
Corrosion 36 • Change pump materials or application
parameters.
Motor overloading Back pressure too high 37 • Increase pipe diameter.
• Reduce working pressure.
• Check accessories (filter, heat exchanger, etc.).
Viscosity too high 38 • Increase axial clearance.
See section 3.21 Maintenance instructions.
• Heat pump.
• Reduce pump speed.
• Increase discharge pipe diameter.
Excessive friction losses inside rotor shaft
/ bearing arrangement
39 • Check/correct axial clearance of circulation pump
and rear face of the rotor
• Check axial axial clearance of the plain bearing
arrangement replace bearing if necessary
Rotor shaft runs against pump cover 40 • Check axial axial clearance of the plain bearing
arrangement replace bearing if necessary