Patent ID: 7222491

Claim:
An air conditioner comprising: a plurality of outdoor units connected in parallel with an indoor unit, each of the outdoor units comprising a plurality of compressors connected in parallel, the compressors being connected by an oil equalizing tube to feed surplus oil in each of the compressors to the remaining compressors, and a connecting tube to connect the oil equalizing tubes of the outdoor units, wherein each of the outdoor units further comprises a check valve arranged at a suction tube connected to one of the compressors included in each outdoor unit, a bypass tube arranged at an outlet of at least one of the remaining compressors, and a bypass opening/closing valve arranged in the bypass tube, wherein the bypass tube is connected to the suction tube downstream from the check valve, wherein an oil equalizing tube opening/closing valve is arranged in the oil equalizing tube of each outdoor unit to cut off flow of lubricant oil through the oil equalizing tube, and wherein a connecting tube opening/closing valve is arranged in the connecting tube.