Service manual

AUX air conditioner service manual
27
It’s not reliable to rely on the electromagnetic reversing valve only for controlling the flow direction
of the refrigerant due to great disparity existing in the working conditions between the cooling and
heating modes of the heat pump air conditioner. Hence, the one-way valve is always applied in the
heat pump air-conditioner in order to switch the refrigerant’s flow directions safely and effectively as
shown in picture 2-11：
In the process of cooling cycle, the difference between the high pressure and the low pressure is small,
the main capillary tube is throttling component, and the auxiliary capillary is short circuited by the
check valve; In heating cycle, the check valve in parallel connection with the auxiliary capillary tubes
is cut off, the refrigerant will flow through the auxiliary capillary, then the throttling components are
the combination of the main capillary tubes and the auxiliary capillary tubes so as to strengthen the
resistance of the throttling component, enlarge the difference between the high pressure and low
pressure of the cycle, reduce the refrigerant temperature of the outdoor heat-exchanger for obtaining
more quantity of heat from outside and achieving the heating purpose.
⑻ Stop valve
In consideration of the convenient installation and service, there are two cut-off valves connecting
separately to the joint entry of the gas tube and liquid tube of the outdoor unit of the split type
air-conditioner. The cut-off valve is a kind of close valve for pipeline. It controls the pass and stop of
the refrigerant flow by manual open-close control valve core. The cut-off valve can be divided into the
two-way cut-off valve and three-way cut-off valve according to the structure difference.
① Two-way cut-off valve
Two direction cut-off valve is used to be installed at the side of the liquid tube, which is belonging to
the tubing of the outdoor unit. The practicality is as picture2-12. The two direction cut-off valve
consists of the position regulator entry and two vertical cross pipelines. The configuration shown in
the picture 2-13 indicates: One of the pipelines connects with the liquid tube side of the outdoor unit,
the other one connects with the tubing of the indoor unit through the connecting tube of the indoor and