Panasonic 9RD198ZAA21 DC Inverter Twin Rotary Compressor – 1.6 HP / 19,300 BTU, R32

Panasonic 9RD198ZAA21 is a DC inverter twin (dual-piston) rotary compressor operating with R32 refrigerant. With a displacement of 19.8 cm³/rev it delivers a cooling capacity of 5,670 W (≈19,346 BTU/h). With its compact R series body, it is used in 18,000-20,000 BTU class R32 split air conditioner outdoor units and heat pumps.

Compact R32 Twin Rotary: 20,000 BTU Class Split AC Compressor

• Twin-piston compression: The pistons operate 180° out of phase; vibration and torque ripple are noticeably lower than with a single piston. This design is essential for a rotary at this capacity.
• 5,670 W cooling / 2,108 W input → COP 2.69 (P-JIS conditions, DC inverter 57.5 Hz measurement).
• Designed specifically for R32: Oil, seals and motor winding are selected for the high discharge temperature of R32.
• DC inverter: Speed is continuously adjusted to the load; on-off cycling is eliminated and consumption drops at partial load.
• Low GWP: The global warming potential of R32 is about one third of that of R410A.

Technical Specifications and Installation Notes

• Model: Panasonic 9RD198ZAA21  |  Supply Code: 10.183.0099  |  Series: R (2-piston)
• Type: Hermetic twin rotary, DC inverter  |  Refrigerant: R32
• Power Class: 1.6 HP  |  Capacity: 5,670 W / ≈19,346 BTU/h
• Power Input: 2,108 W  |  COP: 2.69  |  Displacement: 19.8 cm³/rev
• Measurement Conditions: P-JIS  |  DC inverter 57.5 Hz
• Application: High back pressure (HBP) — air conditioning and heat pumps

• 🔥 R32 is mildly flammable (A2L class). Before brazing/welding, fully recover the refrigerant and purge the system with nitrogen; ventilate the work area and use a leak detector suitable for R32. Do not work on it out of R410A habit.
• It is an inverter compressor and is not connected directly to the mains. It does not run without the driver board; when replacing, verify that the driver is also sound. Measure the winding resistance between the three terminals and check that it is balanced.
• Do not remove the accumulator — it is the only component protecting the compressor against liquid floodback.
• Upright installation is mandatory: Rotary compressors must not be run tilted; fix them upright with vibration mounts.
• Ester oil is hygroscopic: Remove the plugs just before installation and dry the system with a deep vacuum (≤500 micron).