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*.
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*.
Increase Resonance Dampening in
1-64 Resonance Dampening
.
Table 10.1
Basic Troubleshooting
VLT® Refrigeration Drive 110-250 kW Operating Instructions
62
MG16F102 - VLT® is a registered Danfoss trademark
10
10