131
7. Isolate the system from the power supply. Wait at
least 2 min. Switch on the system.
8. Replace compressor.
F.840 Inverter phase currents to compressor asymmetrical
F.840
System characteristics
Heat pump output demand not possible, compressor
not available
Cause
Fluctuating power consumption on compressor, differ-
ential between min. and max. phase currents > 4 A
Possible noises from compressor
Measures
1. Check all cables connected to compressor for cor-
rect seating, contact corrosion and damage.
Replace cable if necessary.
2. Check phase connections for compressor for clock-
wise rotating field.
3. Check the winding resistances of the compressor
stator for symmetry.
4. Check the 3 phase currents on the compressor. If
the phase currents differ from one another, check
the rotating field. Replace phase connections if nec-
essary.
5. Isolate the system from the power supply. Wait at
least 2 min. Switch on the system.
6. Replace inverter.
7. Replace compressor.
F.841 Compressor torque too high
F.841
System characteristics
Compressor running unevenly.
Cause
■
Excessive compressor torque
■
Compressor power consumption too high
Measures
1. Isolate the system from the power supply. Wait at
least 2 min. Switch on the system.
2. Check compressor for increased running noise.
Replace compressor if required.
3. Check software version of the VCMU refrigerant cir-
cuit controller via ViGuide. Run software update if
required.
F.842 Short circuit, inverter internal power module
F.842
System characteristics
Heat pump output demand not possible, compressor
not available
Cause
Inverter short circuit
Measures
1. Check all connections to the compressor:
■
Check wires and plugs for correct seating.
■
Check connections for contact corrosion.
■
Check cables for mechanical damage, e.g. crush-
ing, kinking, chafing or breakage.
Replace cable if necessary.
2. Check phase connections for compressor for clock-
wise rotating field.
3. Isolate the system from the power supply. Wait at
least 2 min. Switch on the system.
4. Replace inverter.
5. Replace compressor.
Messages
Fault messages (cont.)
6218234
Diagnosis
To Next Page