Danfoss VLT FC 280 Operating Manual page 116

VLT® Midi Drive FC 280
Operating Guide
Symptom Possible cause
Mains current imbal- Problem with mains
ance greater than 3% power (see alarm 4,
Mains phase loss de-
scription)
Problem with the
drive unit
Motor current imbal- Problem with motor
ance greater than 3% or motor wiring
Problem with the
drive unit
Acoustic noise or vi- Resonances, for ex-
bration (for example a ample, in the mo-
fan blade is making tor/fan system
noise or vibrations at
certain frequencies)
116 | Danfoss A/S © 2022.02
Test
Rotate input power leads into the drive 1
position: A to B, B to C, C to A.
Rotate input power leads into the drive 1
position: A to B, B to C, C to A.
Rotate output motor leads 1 position: U to
V, V to W, W to U.
Rotate output motor leads 1 position: U to
V, V to W, W to U.
Bypass critical frequencies by using param-
eters in parameter group 4-6* Speed Bypass.
Turn off overmodulation in parameter 14-03
Overmodulation.
Increase resonance damping in parameter
1-64 Resonance Dampening.
Maintenance, Diagnostics, and
Troubleshooting
Solution
If the imbalanced leg follows the
wire, it is a power problem. Check
mains supply.
If the imbalanced leg stays on
same input terminal, it is a prob-
lem with the unit. Contact the
supplier.
If the imbalanced leg follows the
wire, the problem is in the motor
or motor wiring. Check motor and
motor wiring.
If the imbalanced leg stays on
same output terminal, it is a prob-
lem with the unit. Contact the
supplier.
Check if noise and/or vibration
have been reduced to an accepta-
ble limit.
AQ381425076031en-000101 / 130R1223