Abstract: An air conditioner and a method for controlling and air conditioner are provided. The air conditioner may include at least one compressor, a main suction passage to guide a refrigerant into the at least one compressor, at least one oil separator connected to the at least one compressor, that separates oil from the refrigerant discharged from the at least one compressor, at least one oil level sensor disposed in the at least one compressor to detect whether the at least one compressor lacks oil, a return passage to collect the oil separated from the at least one oil separator into the at least one compressor, a distribution return passage branched from the at least one return passage and connected to the main suction passage, and a valve disposed in each of the at least one return passage and the distribution return passage.

Abstract: An air conditioner and a method for controlling and air conditioner are provided. The air conditioner may include at least one compressor, a main suction passage to guide a refrigerant into the at least one compressor, at least one oil separator connected to the at least one compressor, that separates oil from the refrigerant discharged from the at least one compressor, at least one oil level sensor disposed in the at least one compressor to detect whether the at least one compressor lacks oil, a return passage to collect the oil separated from the at least one oil separator into the at least one compressor, a distribution return passage branched from the at least one return passage and connected to the main suction passage, and a valve disposed in each of the at least one return passage and the distribution return passage.

Abstract: An air conditioner and a method of controlling an air conditioner are provided. The air conditioner may include a compressor that compresses a refrigerant and discharges the compressed refrigerant, an outdoor heat exchanger in which outdoor air introduced into an outdoor device and the refrigerant are heat-exchanged with each other, at least one indoor heat exchanger in which indoor air introduced into an indoor device and the refrigerant are heat-exchanged with each other, a plurality of valves respectively disposed in an inflow-side tube and a discharge-side tube of the at least one indoor heat exchanger, and a refrigerant leakage detector that directly or indirectly detects leakage of the refrigerant. When leakage of the refrigerant is detected, the plurality of valves may be blocked or closed in stages.