Manual Compressor Bitzer <720p | UHD>

Refrigeration Engineering Dept. Reviewer: Bitzer Service Manual (KT-660-1) compliant Distribution: Service technicians, commissioning engineers

| Load Step | Solenoid 1 (Cyl. 1&2) | Solenoid 2 (Cyl. 3&4) | |-----------|------------------------|------------------------| | 25% | OFF | OFF | | 50% | ON | OFF | | 75% | OFF | ON | | 100% | ON | ON | manual compressor bitzer

| Symptom | Probable Cause | Manual Corrective Action | | :--- | :--- | :--- | | | Electrical fault / Safety lockout | Check oil pressure switch; reset high-pressure cutout; verify phase monitor status. | | Low Oil Pressure | Oil filter clogged / Low oil level | Replace oil filter; add oil; check for refrigerant dilution in oil (floodback). | | High Discharge Temp | Condenser fouled / Low suction pressure | Clean condenser coils; check for restriction in liquid line; verify Vi setting (Screw). | | Knocking Noise | Liquid floodback / Worn bearings | Check superheat setting at expansion valve; inspect crankshaft and connecting rods for wear. | Refrigeration Engineering Dept

BZ-MAN-2026-04 Date: April 14, 2026 Subject: Manual compressor Bitzer – Operational and maintenance guidelines for manual start, unloader, and oil management. | | Knocking Noise | Liquid floodback /