42
180R9262 / IOM APP 0.6-1.0 Appendices - v02 / 12.2012
Instruction
Trouble shooting guide for APP pumps
5.
Noise from installation
Cause
Remedy
Comments
5.1 Inlet/outlet connections (hoses/pipes)
5.1.1 Use
fl
exible hoses at inlet/outlet connec-
tions. Danfoss A/S can provide
fl
exible
hoses. Please contact Danfoss sales o
ffi
ce
for further information.
5.1.2 Mount the connections to the frame by a
vibration damper mounting plate.
Non-
fl
exible connectionsmounted directly on
the frame will cause even small pressure
pulsations from pump and create vibrations in
the system/plant.
5.2 Length/dimension of inlet/outlet line
5.2.1 Increase pipe diameter and/or reduce the
number of bends.
Too small pipes or too many bends may create
too fast
fl
ow/turbulence through the pipes and
thus increase the noise level.
5.3 Hose sti
ff
ness
5.3.1 Use amore
fl
exible hose. Danfoss A/S can
provide
fl
exible hoses. Please contact
Danfoss sales o
ffi
ce for further informa-
tion.
Too sti
ff
hoses cannot damp the small pressure
pulsations from the pump, and subsequently
vibrations occur in the system/plant.
5.4 Hoses/pipes mounted directly on frame
5.4.1 Mount the connections to the frame by a
vibration damper mounting plate.
If the hoses are mounted directly on the frame,
the small pressure pulsations from the pump
can be transferred to the frame and the rest of
the system/plant.
5.5 Vibration damper under the electric motor
5.5.1 Mount a vibration damper below the
motor/pump.
When no damper is installed below the electric
motor, vibrations from the motor and pump
may be transferred to the frame/r est of the
system/plant.