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Mechanical Specifications - LG ARNU 073 SER2 Engineering Manual

Multi v wall-mounted indoor unit
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StandaRd Wall-Mounted

Mechanical Specifications

Units are designed to mount on a vertical surface and come com-
plete with an installation mounting guide and a separate hanging
bracket. The unit case is manufactured with coated metal. Cold
surfaces are covered with a coated polystyrene insulating material.
The unit case is manufactured using ABS polymeric resin and has a
pearl white finish.
Fan Assembly and Control
The unit has a single, direct-drive, crossflow tangential Sirocco fan
made of high strength ABS BSN-7530 polymeric resin. The fan motor
is a Brushless Digitally-Controlled, (BLDC) design with permanently
lubricated and sealed ball bearings. The fan motor includes thermal,
overcurrent and low RPM protection. The fan/motor assembly is
mounted on vibration attenuating rubber grommets. The fan impeller
is statically and dynamically balanced. The fan speed is controlled
using a microprocessor-based direct digital control algorithm that
provides a high fan speed in cooling thermal ON and low fan speed
in cooling thermal OFF, high fan speed in heating thermal ON and
fan off in heating thermal OFF. The fan speeds can be field adjusted
between low, medium, and high speeds. The fan speed algorithm
provides a field-selectable fixed-speed or auto-speed setting that
changes the fan speed to simulate natural airflow.
Air Filter
Return air is filtered with a removable, washable filter with anti-fun-
gal treatment. The unit is also equipped with a plasma filter. Filter
access is from the front of the unit without the use of tools.
Airflow Guide Vanes
7–15 MBh
The indoor unit is provided with a motorized oscillating guide vane
that automatically changes the direction of up-and-down airflow.
The indoor unit includes factory installed, manually adjustable guide
vanes that control the side-to-side direction of supplied airflow.
18-36 MBh
The indoor unit is provided with a motorized sweeping guide vane
that automatically changes the direction of airflow from side-to-side
and up-and-down.
Microprocessor Control
The unit is provided with an integrated microprocessor controller ca-
pable of performing functions necessary to operate the system with-
out the use of a wall-mounted controller. A temperature thermistor is
factory mounted in the return air stream. All unit operation param-
eters, excluding the operating schedule, are stored in non-volatile
memory resident on the unit microprocessor. Operating schedules
are stored in select models of the optional, wall-mounted, local or
central controllers. The field-supplied communication cable between
the indoor unit(s) and outdoor unit is to be a minimum of 18 AWG,
2 conductor, stranded, and shielded cable (RS-485), terminated via
screw terminals on the control boards. The microprocessor control
provides the following functions: auto addressing, self-diagnostics,
auto restart following power restoration, test run, and will operate the
indoor unit using one of five operation modes:
1. Auto Changeover (Heat Recovery only)
2. Heating
3. Cooling
4. Dry
5. Fan Only
34 | StAndArd
Due to our policy of continuous product innovation, some specifications may change without notification.
LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. "LG" is a registered trademark of LG Corp.
For Heat Recovery systems
the Auto Changeover setting
automatically switches
control of the indoor unit
between Cooling and Heat-
ing modes based on space
temperature conditions.
For Heat Pump systems, heated or cooled air delivery is dependent
upon outdoor unit operating mode.
In Heating mode, the microprocessor control will activate indoor unit
operation when the indoor room temperature falls below set-point
temperature. At which point, a signal is sent to the outdoor unit to
begin the heating cycle. The indoor unit fan operation is delayed until
coil pipe temperature reaches 76°F. Significant airflow is generated
when pipe temperature reaches 80°F. A field-selectable option
maintains fan operation for 30 minutes following cooling cycle
operations. The unit is equipped with an infrared receiver designed
to communicate with an LG wireless remote controller. In lieu of
wireless remote or factory return air thermistor, screw terminals on
the microprocessor circuit board accommodates various models of
wall-mounted local controllers. The unit microprocessor is capable
of accepting space temperature readings concurrently or individually
from either:
1. Wall-mounted wired controller(s)
2. Factory-mounted return air thermistor
A single indoor unit has the capability of being controlled by up to
two local wired controllers. The microprocessor controls space tem-
perature using the value provided by the temperature sensor sensing
a space temperature that is farthest away from the temperature
set-point. The microprocessor control provides a cooling or heating
mode test cycle that operates the unit for 18 minutes without regard
to the space temperature. If the system is provided with an optional
wall-mounted local or central controller, displayed diagnostic codes
are specific, alpha-numeric, and provide the service technician with a
reason for the code displayed.
Handling Condensate
The unit is designed for gravity draining of condensate. LG provides
a factory insulated flexible drain hose. If condensate lift/pumps are
needed for the application, they are to be field provided.
Condensate Drain Pan
The condensate drain pan is constructed of expandable polystyrene
resin (EPS).
The indoor unit coil is constructed with grooved design copper tubes
with slit coil fins, two (2) rows, eighteen (18) fins per inch.
Controls Features
• Auto changeover
(Heat Recovery only)
• Auto operation
• Auto clean (coil dry)
• Child lock
• Dual thermistor control
• Dual set-point control
• Filter life and power consump-
tion display
• Multiple auxiliary heater
Requires wireless controller.
• Group control
• Forced operation
• Hot start
• Self diagnostics
• Timer (on/off)
• Weekly schedule
• Auto direction/swing (up/down)
• Fan speed control
• Jet cool (fast cooling)

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