Series MNKA bearing pedestal assembly 4
Page 25
9250-003-en
Revision 01
TM 10458
Published 06/2022
8
Faults
Faults can occur due to impermissible
methods
of
operation. Improper
methods of operation, even for short
periods, can result in serious damage
to the unit.
In terms of explosion protection, potential ignition
sources (overheating, electrostatic and induced
charges, mechanical and electrical sparks) can
result from these improper methods of operation.
This can only be prevented by observing the
proper use.
See also
section 6.5
.
If there is any uncertainty about the remedial
method to be used, please consult the in-house
pump department or the pump manufacturer.
No delivery:
♦
Is the pump filled and vented?
♦
Is the suction line open, vented, cleaned and
correctly routed?
♦
Is the discharge line open, vented, cleaned and
correctly routed?
♦
Is the geodetic head too high?
♦
Is air being sucked in?
♦
Is the magnetic coupling torn off?
Delivery rate too low:
♦
Have the pump, suction line and pressure line
been completely vented, filled and cleaned?
♦
Have any dirt traps been cleaned?
♦
Are all shut-off devices open?
♦
Is the geodetic head too high?
♦
Is the NPSHA too low or the NPSHR too high?
♦
Are the pipe resistances too high?
♦
Is the viscosity too high?
♦
Is the direction of rotation correct?
♦
Is the speed too low or the impeller diameter
too small?
♦
Are pump parts worn?
♦
Is there gas in the medium?
Flow rate too high:
♦
Is the geodetic head too low?
♦
Are the pipe or nozzle resistances too low?
♦
Is the pump speed or impeller diameter too
high?
Delivery pressure too high:
♦
Is the speed or impeller diameter too high?
♦
Is the density too high?
Motor draws too much current:
♦
Are the flow rate, density or viscosity too high?
♦
Is the speed too high or impeller diameter too
large?
♦
Is the coupling correctly aligned?
♦
Can the drive shaft be turned properly?
Pump runs unsteadily or noisily:
♦
Is the coupling well aligned?
♦
Are the coupling assemblies worn?
♦
Are the rolling bearings damaged?
♦
Are parts of the hydraulics damaged?
♦
Is the flow rate too low or too high?
♦
Is the impeller balanced?
♦
Is the pump strained?
♦
Are there foreign bodies in the pump?
Temperature of the rolling bearings is too
high:
♦
What is the actual measured temperature?
♦
How high may this be according to the operat-
ing instructions?
♦
Is the running-in phase already over?
♦
Lack of lubricant?
♦
Overageing/wear?
Leakage at the pump:
♦
Are all screws tightened to the correct torque?
♦
Have the sealing surfaces been assembled in
a clean condition?
♦
Have approved seals been installed?
