The QP series is the highest-capacity R22 series among LG fixed-speed rotary compressors, specifically designed for tropical applications. It covers the demand for high-power air conditioning and refrigeration equipment in the range of approximately 2 to 2.5 horsepower.
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Tropical-specific reinforced design: The QP series is labeled by LG as "Special application for Tropical," optimized for high-temperature environments.
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High energy efficiency: The series achieves a COP generally between 3.16 and 3.28 W/W. The QP407P reaches up to 3.28, and the QP325P reaches 3.22, placing them at the world's highest efficiency level among non-inverter rotary compressors.
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Broad application adaptability: Suitable for a wide range of equipment including air conditioners, chillers, dryers, and more.
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Wide voltage tolerance: Designed to be compatible with different global power grid environments, ensuring stable operation under wide voltage fluctuations.
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High reliability + low vibration and noise: Inheriting the simple yet robust structural advantages of LG fixed-speed rotary compressors.
Q1: Poor cooling performance?
A: In large-capacity scenarios, poor cooling with the QP series is often not caused by the compressor itself, but rather by refrigerant leakage, dirty/clogged filters or condenser coils, restricted airflow, or a faulty thermostat. Field experience shows that technicians sometimes spend hours troubleshooting the compressor, only to find the real culprit is a blocked condenser coil — a situation that is far from uncommon.
Q2: Why is protection against liquid slugging emphasized?
A: Rotary compressors are extremely sensitive to liquid refrigerant. Since liquid is incompressible, entering the compression chamber can overload the motor, dilute the lubricating oil, and cause a sharp increase in friction, leading to thermal expansion and eventual seizure. For the QP high-capacity series, special attention must be paid during system design to ensure the accumulator functions properly and the oil return holes remain unobstructed. Additionally, foreign particles larger than 100 μm must be prevented from entering the compression chamber to avoid stalling. This is also the fundamental reason why the drier filter must be replaced and a strict vacuum pull must be performed whenever replacing a QP series compressor.
