On Sat, 18 Mar 2006 18:05:00 GMT, Alex
wrote:

I think I found it in this manual:
http://www.baldor.com.au/products/pd...D%20manual.pdf

Motor Frequency Multiplier Selection (J6) ? Jumper
J6 is factory set to the ?1X? position, for motor frequency
corresponding to the frequency setting of Jumper J5 (50
or 60 Hz). To double the output frequency to the motor,
set Jumper J6 to the ?2X? position (100 or 120 Hz). See
Figure 14.
Note: When doubling the motor frequency, the motor
will produce full torque up to its rated speed. The torque
will be linearly reduced to 50% at the maximum doubled
frequency.

Am I right?


wrote:

Have a closer look - practically all VFDs have a facility to
change this frequency. Low for maximum power handling and long
leads between VFd and load motor. Higher for minimum noise.

The data sheet is of no help.You need the full manual - there
may be as many as a 100 possible performance tweaks!

Names vary a bit - pulse frequency or carrier frequency are
the common ones. Some VFDs have a two tier menu system. The first
tier is easily accessible and contains the frequently used
control variables. The second tier contains the full range of
possibilities but can only be accessed after entering a special
access code.

Jim

The manual that you posted shows that the carrier frequency
for your.VFD is fixed at 16KHz with no facility for adjustment.
This is right at the very top of the range of commonly provided
carrier frequencies (about 2 to 16Khz). Since this is well above
audible frequency and corresponds to minimum noise this is
unlikely to be the cause of your high noise level.

The double motor frequency setting is a useful one
which enables motor operation well beyond its nameplate speed.
Since the carrier frequency is unaltered, will have little effect
on noise level.

Not very helpful I'm afraid - a call to the
manufacturer may help!

Jim