Samsung AM18A1C09 Owner's Instructions & Installation Manual page 32

On delivery, the indoor unit is loaded with an inert gas. All this gas
must therefore be purged before connecting the assembly piping.
To purge the inert gas, proceed as follows.
To prevent dirt or foreign objects from getting into the pipes
during installation, do NOT remove the caps completely
until you are ready to connect the piping.
The indoor unit is powered from the outdoor unit via the assembly
cable. If the outdoor unit is more than five metres away from the
indoor unit, the cable must first be extended to a maximum of
ten metres.