Johnson Controls Penn VFD68D Series Technical Bulletin page 73

Table 71: Motor or Machine Generates Abnormal Acoustic Noise
Check Possible Cause
Points
Param. Resonance occurs (mechanical system
Setting resonance frequency)
Resonance occurs (carrier frequency)
Others Mechanical looseness
Motor Operating with output phase loss
Table 72: VFD Generates Abnormal Acoustic Noise
Check Possible Cause
Points
Fan The fan cover was not correctly installed when a
cooling fan was replaced.
Table 73: Motor Generates Heat Abnormally
Check Possible Cause
Points
Param. The fan motor is running too slowly to create
Setting airflow.
Motor The fan motor is not working (dust is
accumulating.)
Phase to phase insulation of the motor is
insufficient.
Main The VFD output voltage (U, V, W) are
Circuit unbalanced.
Table 74: Motor Rotates in the Opposite Direction
Check Possible Cause
Points
Main Phase sequence of output terminals U, V and W
Circuit is incorrect.
Action
•
•
When it is desired to avoid resonance attributable to the
natural frequency of a mechanical system, these
parameters allow resonant frequencies to be jumped.
Change P. 72 setting.
Changing the PWM carrier frequency can reduce the
audible noise created when the motor is running at
speeds slower than the maximum rated speed (see
PWM Frequency, Audible Motor Noise, and EMI on
page 52).
Adjust machine/equipment so that there is no
mechanical looseness.
Check the motor wiring. Contact the motor
manufacturer.
Action
Install the fan cover correctly.
Action
Verify that P. 31 is set to 0 and P. 32 is set to 12.5 Hz. If
12.5 Hz is too slow, increase frequency for
•
•
Clean the motor fan.
Improve the environment.
Check the insulation of the motor.
Check the output voltage of the VFD.
Check the insulation of the motor.
Action
Connect phase sequence of the output cables
(terminals U, V, W) to the motor correctly
VFD68 Variable Frequency Drives
73
For Frequency Jump 2, set P. 33 and P. 34.
For Frequency Jump 3, set P. 35 and P. 36
P.32, C 2, C 5 (VFD68Bxx and VFD68Cxx
models)
P.32, P.902a, P.904a (VFD68Dxx models).