KSB RWCN, Original Manual

Page: 16 / 20

RWCP, RWCN
16
8 Trouble-shooting
The pump does not move the fluid
| Insufficient pressure or flow
| | Excessive absorbed power
| | | Excessive vibrations and noise
| | | | Excessive support temperature
| | | | | Loss of fluid through the mechanical seal
| | | | | | Wear rings deteriorate quickly
| | | | | | |
Cause Solution
x x
Suction or impulsion valves closed or poorly
regulated Open the suction valve or search for work
point with the impulsion valve
x Incorrect rotation direction Change the motor connections
x x Pipes or impeller obstructed Dismount and unblock
x x x Pump not correctly submerged Check minimum submergence (See point -)
x x
Maximum height generated by the pump lower
than that required by the installation or counter
pressure too high. Increase the rotation speed. If this is not
possible, a larger impeller or larger pump
needs to be assembled. Please ask
x Rotation speed incorrect
Measure the speed, check the motor drive
power supply voltage
x x
Wear rings or bearings deteriorated or incorrectly
assembled
Dismount and change, or reinstall them
x Leaks between the casing and pipes Dismount and check the joints
x
Unsuitable installation/disturbances from other
pumps
Check with the installer
x Liquid viscosity or density greater than normal.
Reduce the design point or change the
motor
x x x x Poor motor assembly Check and clean the pump-motor joint.
x Obstruction inside the pump.
Dismount the pump and clean the impeller,
inlets or pipe
x
The real height to be generated by the pump is
lower than that of the design point, meaning the
flow and power are greater
Partially close the impulsion valve
x x x
Ballbearings deteriorated, poorly assembled or
poorly lubricated
Check them, check the assembly or
lubricate them, adjust them properly in their
positions.
x Excessive contact in rotating parts
Dismount the pump and check elements are
correctly assembled and/or worn
x x x x Misaligned or deformed shaft Dismount it and replace it
x Loose impeller support nuts Dismount the pump and tighten them
x x x x Pipe tensions on the pump Check the installation
x
Lack of rigidity in the foundations or anchor bolts
loose
Make new foundations or tighten the bolts
x Pump cavitation Improve the suction. Please ask.
x x x Impeller imbalanced or deteriorated Balance the impeller or change it
x x Bearings excessively worn or deteriorated Change bearings
x
Very deteriorated mechanical seal, seal spring
broken or without elasticity, poorly assembled
seal, or joints broken, deformed or without
elasticity, or contact faces of the seal very
deteriorated.
Dismount and replace the seal, or dismount,
review damage and change as appropriate.
x High suction pressure Please ask
x Re-changeable bushing scratched or deteriorated Dismount and change the bushing