Symptom Possible cause Test Solution
Acoustic noise or vibration
(e.g. a fan blade is making
noise or vibrations at
certain frequencies)
Resonances, e.g. in the motor/fan
system
Bypass critical frequencies by using
parameters in parameter group
4-6* Speed Bypass
Check if noise and/or vibration
have been reduced to an
acceptable limit
Turn off over-modulation in
14-03 Overmodulation
Change switching pattern and
frequency in parameter group
14-0* Inverter Switching
Increase Resonance Dampening in
1-64 Resonance Dampening
Table 10.1 Troubleshooting
Basic Start-up Troubleshoot... Operating Instructions
138 Danfoss A/S © Rev. 2014-07-29 All rights reserved. MG37A202
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