Carrier 38QUS012D8S Service Manual page 28

1.9 Twins Function
 The twin system connects two indoor units of the same type and capacity to one outdoor unit in order to
ensure more air distribution in a large zone. The controller can only control the master unit. The slave
unit will work in the same state as the master unit.
1.10 Fresh air intake function(Optional)
 Install one duct from the reserved fresh-air intake to outdoor.
Continually inhale the fresh air to improve the quality of the indoor air, fulfills air quality more healthy and
comfortable.
 A ventilation motor (provided by the installer) can be installed inside the fresh air duct to improve the
fresh air volume. There are reserved ports for this motor on main PCB (Standard for 3D inverter units,
and only optional for DC inverter 53~160 units).
1.11 Built-in drain pump (Optional)
 Built-in drain pump can lift the water to 750mm upmost, which widens the drainage piping range.
Indoor Units
Features
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