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DUCT (LOW STATIC) INDOOR UNITS
Ceiling-Concealed Duct (Low Static)
Indoor Unit
General
All LG indoor units are factory assembled, wired, piped, and pro-
vided with a control circuit board, fan, and motor. Ceiling-Concealed
Duct (Low Static) units have a sound rating no higher than 36 dB(A)
as tested per KSA0701 ISO Standard 3745, and are designed for
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Coil
Indoor unit coils are factory built and are comprised of aluminum fins
mechanically bonded to copper tubing. Each unit has two rows of
coils, which are pressure tested at the factory. Each unit is provided
with a factory installed condensate drain pan below the coil.
Refrigerant System
System is designed for use with R410A refrigerant. The refrigeration
circuit is pressure-tested at the factory and shipped with a holding
charge of helium gas. Refrigerant pipe connections are 45° flare,
and all refrigerant lines from the outdoor unit to the indoor units must
be field insulated.
Electrical
Each indoor unit is designed to operate using 208–230/60/1 power
with voltage variances of ±10%.
Casing
The case has a low profile design with a maximum height of 7.5
inches designed to mount fully concealed above a finished ceiling in
as little as 8 inches vertical space. Casing is manufactured of gal-
vanized steel plate, and provided with hanger brackets designed to
support the weight on four corners. Unit has a front horizontal supply
air discharge outlet, and one rear horizontal return air inlet; unit is
also field-convertible for a rear bottom return.
Fan Assembly and Control
The units have at least two direct-drive, Sirocco fans made of
high strength ABS HT-700 polymeric resin that are statically and
dynamically balanced. The fans are mounted on a common brush-
less digitally controlled (BLDC) motor with permanently lubricated
and sealed ball bearings. The fan / motor assembly is mounted on
vibration-attenuating rubber grommets. Fan speed is controlled using
a microprocessor-based direct digital control algorithm. The indoor
fan has Low, Med, High, and Auto settings for Cooling mode; and
has Low, Med, High, and Auto settings for Heating mode. Each of the
settings can be field-adjusted from the factory setting (RPM / ESP).
The Auto setting adjusts the fan speed based on the difference be-
tween the controller set-point and space temperature.
Air Filter
Return air is filtered with a factory-supplied, removable, washable
filter accessible from the rear of the indoor unit.
Microprocessor Control
The unit is provided with an integrated control panel to communicate
with the outdoor unit. All unit operation parameters are stored in non-
volatile memory residing on the unit microprocessor. The micropro-
cessor controls space temperature through using the value provided
by the temperature sensor within the indoor unit. The microprocessor
control will activate indoor unit operation when the indoor room tem-
perature falls below or rises above a setpoint temperature, at which
point, a signal is sent to the outdoor unit to begin the appropriate
mode. The microprocessor will also provide self-diagnostics and auto
restart functions. A field-supplied four-wire power / communications
cable must be installed to connect the indoor unit(s) to the outdoor
unit.
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device are required. The Smart ThinQ app is free, and is available
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Controls
The indoor unit controller of choice must be ordered separately.
Communication between the indoor units and the outdoor unit is
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unshielded power / communication cable.
Condensate Lift/Pump
The indoor unit is provided with a factory installed and wired conden-
sate lift/pump capable of providing a minimum 27.5 inch lift from the
bottom surface of the unit. Drain pump has a safety switch to shut off
the indoor unit if the condensate rises too high in the drain pan.
• Inverter (Variable speed fan)
• External mounted drain pump
• Control lock function
• Auto operation
• Auto restart operation
• Dehumidification function
• Two thermistor control
• External static pressure control
• Self-diagnostics function
• Group control
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Features
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DUCT (LOW STATIC) | 73
Ceiling-Concealed Duct (Low Static)
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