Four-way valve

(9)Outdoor unit heat exchanger capacity control

1)Control method

•In order to stabilize the evaporation temperature during cooling and the high-pressure pressure during heating that are required in response to performance needs, the capacity of the outdoor heat exchanger is controlled by regulat- ing the fan volume of the outdoor unit by phase control and controlling the number of fans and by using the solenoid valves to vary the number of out door heat exchangers being used.

2)Control

•When both of the compressors are stopped, the fans for the outdoor units are also stopped.

•The fans operate at full speed for 5 seconds after starting.

•The fans for the outdoor unit are stopped during defrosting.

3)Capacity control pattern

Operation mode	Operation pattern		Solenoid valve
Operation mode	Operation pattern	SV4	SV5	SV6	SV7	SV8
	SV3	SV4	SV5	SV6	SV7	SV8
	ON	ON	ON	OFF	ON	ON
	ON	ON	ON	OFF	OFF	OFF
Full cooling	OFF	ON	ON	OFF	OFF	OFF
Full cooling	OFF	ON	OFF	OFF	OFF	OFF
	OFF	ON	OFF	OFF	OFF	OFF
	OFF	OFF	ON	OFF	OFF	OFF
	OFF	OFF	OFF	OFF	OFF	OFF
	ON	ON	ON	OFF	ON	ON
	ON	ON	ON	OFF	OFF	OFF
	OFF	ON	ON	OFF	OFF	OFF
Cooling mainly	OFF	ON	OFF	OFF	OFF	OFF
	OFF	OFF	ON	OFF	OFF	OFF
	OFF	OFF	OFF	OFF	OFF	OFF
	OFF	OFF	OFF	ON	OFF	OFF
Full heating	ON	ON	ON	OFF	ON	ON
	ON	ON	ON	OFF	ON	ON
Heating mainly	ON	ON	ON	OFF	OFF	OFF
Heating mainly	ON	ON	ON	ON	OFF	OFF
	ON	ON	ON	ON	OFF	OFF
	OFF	OFF	OFF	ON	OFF	OFF
Defrosting	ON	ON	ON	OFF	ON	ON

*In stop, all are OFF.

(10)Circulating composition sensor (CS circuit)

•As shown in the drawing below; the CS circuit has the structure to bypass part of the gas discharged from the compres- sor through the capillary tube to the suction side of the compressor, exchange heat before and after the capillary tube, and produce two phase (gaseous and liquid) refrigerant at the capillary tube outlet. The dryness fraction of refrigerant at the capillary tube outlet is estimated from the temperature of high pressure liquid refrigerant at the capillary tube inlet

(TH9) and the temperature of low pressure two phase (gaseous and liquid) refrigerant at the capillary outlet (TH2) and the pressure (LPS) to calculate the composition of refrigerant circulating the refrigeration cycle (α OC). It is found by

utilizing the characteristic that the temperature of two phase (gaseous and liquid) R407C under a specified pressure changes according to the composition and dryness fraction (gas-liquid ratio in weight).

•The condensing temperature (Tc) and the evaporating temperature (Te) are calculated from α OC, high pressure (HPS), and low pressure (LPS).

•The compressor frequency, the outdoor fan, and others are controlled according to the codensing temperature (Tc) and the evaporating temperature (Te).

•CS circuit configuration (Outline drawing)

heatexchanger	Compressor	Heat exchanger TH9
		TH2
Outdoor
		LPS

Separate compressor

Indoor heat	exchanger
control

Accumulator

CS circuit

–45–

Flow valve

PURY-P400, P500YMF-C specifications

Mitsubishi Electronics has long been a leader in the HVAC industry, known for its innovative technology and reliable performance. Among its notable offerings are the P500YMF-C and PURY-P400 models, designed to address the diverse needs of commercial and residential applications.

The Mitsubishi P500YMF-C is a high-performance outdoor unit that showcases energy efficiency and advanced refrigerant technology. It employs a sophisticated inverter-driven compressor, which optimizes energy usage by adjusting its speed based on the specific heating and cooling demands of the environment. This flexibility helps to minimize energy consumption while ensuring optimal comfort.

One of the standout features of the P500YMF-C is its ability to provide consistent heating and cooling even in extreme outdoor temperatures. The unit can operate effectively in low-temperature conditions, making it ideal for regions with harsh winters. Furthermore, the system is designed with a robust build, ensuring durability and longevity.

On the other hand, the PURY-P400 is an indoor multi-split system that complements the outdoor unit perfectly. It's designed for versatility and efficiency, capable of accommodating multiple indoor units connected to a single outdoor unit. This feature is particularly beneficial for larger spaces or buildings where different zones require individual climate control.

The PURY-P400 incorporates Mitsubishi's advanced filtration technology, which significantly improves indoor air quality. It features a multi-layer filtration system that effectively removes dust, allergens, and other particulates from the air, ensuring a healthier environment for occupants.

Both systems utilize R-32 refrigerant, which has a lower global warming potential compared to traditional refrigerants. This not only makes them more eco-friendly but also complies with emerging environmental regulations. The ease of installation and operation of these units is another noteworthy characteristic, with intuitive controls and user-friendly interfaces that facilitate seamless integration into existing systems.

In summary, the Mitsubishi P500YMF-C and PURY-P400 represent a fusion of technology, efficiency, and user-centric design. With a range of features aimed at enhancing performance and environmental sustainability, these models are an excellent choice for anyone looking to invest in a reliable and efficient HVAC system. Whether for residential or commercial use, Mitsubishi’s offerings continue to set the standard in comfort and efficiency.

Mitsubishi Electronics PURY-P400 Four-way valve, Heat exchanger TH9, Accumulator CS circuit

Models: PURY-P400 P500YMF-C