Compressor description by Ralkin

BITZER ECOLINE 2-Stage Compressor S4G-12.2

The BITZER ECOLINE 2-Stage compressors are the best choice for extended low-temperature applications with a variety of refrigerants. This series is the result of extensive research and experience, boasting an especially robust construction, an optimized drive gear, and an efficient motor. They are designed for durability and reliability and are available as both single and tandem compressors. The gas ports and working valves are specifically matched to low-temperature operation to achieve the highest performance.

Model Identification

• S: Identification letter for 2-stage construction.
• 4: Index for number of cylinders (4).
• G: Identification letter for bore x stroke.
• 12: Code for motor size.
• .2: Index for series.
• (Y): Identification letter for ester oil charge (for HFC refrigerants like R404A/R507A/R448A/R449A). Note: The request 'S4G-12.2' typically implies the standard series; if 'Y' is not present, it may default to Mineral/Ester oil depending on specific manufacturing year, but 'Y' is standard for modern HFC retrofits.

Technical Features

• Design: Short gas canals for minimum heat exchange, solid valve plate design with impact-resistant spring steel reeds, compact dimensions, and quiet/low-vibration operation due to optimized mass balance.
• Performance: High refrigerating capacity with minimal energy requirements due to highly efficient working valves, minimal dead space, and a large volume, gas-cooled motor.
• Drive Gear: Wear-resistant design with surface-hardened eccentrics and crankshafts, a sealed main bearing, patented oil return system, and low-friction components.
• Lubrication: Pressure oil lubrication via a reversible gear pump.
• Protection: Electronic thermal monitoring with PTC sensors and an integrated differential pressure relief valve.
• Cooling: Liquid injection for intermediate cooling is standard, usable with a mechanical TX valve or an electronically controlled CIC® system.
• Enclosure: IP54 terminal box (optional IP66).

Specifications & Data

• Displacement (LP Stage): 42.3 m³/h
• Displacement (HP Stage): 27.0 m³/h
• Number of Cylinders: 4
• Oil Charge: 4.5 dm³
• Weight: 180 kg
• Discharge Line Connection: 28 mm (1 1/8 inch)
• Suction Line Connection: 35 mm (1 3/8 inch)
• Motor Connection: 380..420V Y/3/50, 440..480V YY/3/60
• Max. Operating Current: 24 A
• Max. Power Consumption: 13.8 kW
• Starting Current (Locked Rotor): 69/113 A (Y/YY)

Performance Data

• Refrigerating Capacity (Q₀): 9.78 kW
• Conditions: R448A/449A, tₑ= -35°C; t꜀= 40°C, 10K suction gas superheat.