46 Carrier — Oil recovery failure / olio compressore non ritorna
At a glance
- Severity
- FAULT STOP
- Domain
- VRV_VRF_system
- Reference standard
- EN 378-2:2016, ASHRAE 15-2019
- Product / context
- Oil pressure differential fault
What it means
The automatic oil recovery procedure of the VRV/VRF system does not complete successfully. The oil level in the compressor drops below the minimum, risking bearing seizure and permanent damage. The system periodically attempts the oil recovery cycle but fails.
Probable causes
- Refrigerant charge loss preventing oil transport
- Piping with oil traps due to excessively long runs or too many bends
- Defective check valve on the oil line
- Compressor with already critically low oil level unable to generate sufficient pressure
- Clogged oil filter in the circuit
Where to start
Critical situation. Stop the compressor immediately. Check refrigerant charge (if low, oil will not return). Look for leaks. Top up oil with a compatible type before restarting.
Full guided diagnosis in the app
The diagnostic tree for this fault has 6 guided steps with measurements, checks and resolutions. You'll find it in HVACIQ, one of the four IndexOS apps: free, works offline.
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