Outdoor unit for air conditioning and air conditioner

An outdoor unit of an air conditioner, the outdoor unit comprising:

• a compressor configured to compress a refrigerant;
• an outdoor heat exchanger configured to exchange heat between the refrigerant and outdoor air;
• a first switching valve configured to selectably:
• disconnect a discharge side of the compressor and indoor heat exchangers of all of indoor units, thereby causing to cause the outdoor heat exchanger to function as a condenser, and
• connect the discharge side of the compressor to the indoor heat exchanger of at least one of the indoor units, thereby causing the indoor heat exchanger of the at least one of the indoor units to function as a condenser;
• a second switching valve configured to selectably:
• connect the discharge side of the compressor to the outdoor heat exchanger, thereby causing the outdoor heat exchanger to function as a condenser, and
• connect a suction side of the compressor to the outdoor heat exchanger, thereby causing the outdoor heat exchanger to function as an evaporator;
• an outdoor first pipe that connects the outdoor heat exchanger and the indoor units;
• an outdoor second pipe that is one of branches of the first switching valve and connects the compressor and the indoor units;
• and
• an outdoor third pipe that is connected to one of the branches of the first switching valve and is connected to the compressor, wherein
• in response to the outdoor first pipe, the outdoor second pipe, and the outdoor third pipe being connected to the indoor units via a plurality of switching units that switch a flowing direction of the refrigerant flowing to the indoor units, the outdoor third pipe makes a detour around the first switching valve to connect the compressor and the indoor units, and
• the outdoor third pipe includes a main flow pipe portion through which, in response to the outdoor first pipe and the outdoor second pipe being connected to the indoor units without interposing the plurality of switching units, the refrigerant to be sucked into the compressor through the first switching valve flows and a trap portion that intersects the main flow pipe portion, branches off, and then goes downwards.