Daikin Sky Air Advance RZA200D7Y1B, Service Manual

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1 | General operation
Service manual
7
250D7Y1B
Sky Air Advance-series
ESIE19-13A – 2020.05
1 General operation
The Sky-Air is typically used for cooling or heating in commercial applications.
Some units also have settings to perform technical cooling. The medium which is
used to transfer the heat from inside to outside or vice versa, is refrigerant. In case
of the 250D7, the refrigerant which is used, is R32.
There are four different piping combinations to indoor units:
▪ Pair
▪ Twin
▪ Triple
▪ double twin.
They all have the same operation principle. Unlike multi‑system, they have only
one main expansion valve controlling the refrigerant flow to all indoor unit(s).
a
b
c
d
e
f
f
b
a Compressor
b Indoor heat exchanger (up to 4 indoor units)
c Expansion valve
d Outdoor heat exchanger
e 4‑way valve
f Stop valve
In case of heating, the compressor builds up pressure and hence the temperature
of the refrigerant is increased. The hot refrigerant is blown into the room by fan(s)
which blow over heat exchanger(s). Colder refrigerant flows back to the outdoor
unit, where temperature is further decreased by expansion through an expansion
valve. After the expansion valve, the refrigerant is capable of taking up heat again.
This is enabled by a fan that sucks outdoor air over a heat exchanger. This
refrigerant is then transported to the compressor where temperature is further
built up again and the cycle starts again. For cooling, it’s just the other way round.
Indoor units
Sky-Air systems have combination limits for different types of indoor units and also
limits for piping length and connection ratio for each indoor unit combination
pattern. Refer to the Engineering Databook.