Acoustic Noise Or Vibration - Danfoss FC 100 Series Operating Instructions Manual

Troubleshooting
ALARM 248, Illegal power section configuration
This alarm is only for F Frame drives. It is equivalent to Alarm
79. The report value in the alarm log indicates which power
module generated the alarm:
1 = left most inverter module.
2 = middle inverter module in F2 or F4 drive.
2 = right inverter module in F1 or F3 drive.
3 = right inverter module in F2 or F4 drive.
5 = rectifier module.
ALARM 250, New spare part
The power or switch mode power supply has been exchanged.
The frequency converter type code must be restored in the
EEPROM. Select the correct type code in par. 14-23 Typecode
Setting according to the label on the unit. Remember to select
'Save to EEPROM' to complete.
ALARM 251, New type code
The frequency converter has a new type code.

8.2 Acoustic Noise or Vibration

If the motor or the equipment driven by the motor - e.g. a fan
blade - is making noise or vibrations at certain frequencies, try
the following:
•
Speed Bypass, parameter group 4-6*
•
Over-modulation, par. 14-03 Overmodulation set to
off
•
Switching pattern and -frequency parameter group
14-0*
•
Resonance Dampening, par. 1-64 Resonance
Dampening
®
VLT HVAC Drive Operating Instructions
®
MG.11.AD.02 - VLT is a registered Danfoss trademark
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