Mechanical Specifications - LG ARNU 073 SER2 Engineering Manual

aRt cool
tM

Mechanical Specifications

Casing
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.
Finish
The unit case has a light gray/silver matte finish. The front surface of
the unit has an architectural flat panel smoked mirror 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 antifun-
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
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
capable of performing functions necessary to operate the system
without the use of a wall-mounted controller. A temperature therm-
istor is factory mounted in the return air stream. All unit opera-
tion parameters, 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, two conductor, stranded, and shielded cable (RS-485), termi-
nated via screw terminals on the control boards. The microprocessor
control provides the following functions: 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
For Heat Recovery systems the Auto Changeover setting automati-
cally switches control of the indoor unit between Cooling and Heating
16 | Art Cool
tM
MIRRoR
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.
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 setpoint 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
accommodate 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 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 EPS (expandable poly-
styrene resin).
Coil
The indoor unit coil is constructed with grooved design copper tubes
with slit coil fins, two (two) rows, eighteen (18) fins per inch.
Controls Features
• Auto changeover
(Heat Recovery only)
• Auto operation
• Auto clean (coil dry)
1
• Child lock
• Dual thermistor control
• Group control
Requires wireless controller.
1
• Hot start
• Self diagnostics
• Timer (on/off)
• Weekly schedule
• Auto direction/swing (up/down)
• Auto direction (left/right)
• Fan speed control
• Jet cool (fast cooling)