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Product Data
Due to our policy of continuous product innovation, some specifications may change without notification.
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General Information
LG Electronic’s Inverter Scroll Chillers provide chilled water for
cooling-only, commercial air conditioning systems using air-handling
units, fan coil units, etc. The single frame 20-ton ACAH chiller uses
R410A refrigerant, applies air-cooled condenser technology; in-
cludes scroll compressors, electronic expansion valves, evaporator,
and LG Human Machine Interface (HMI); and is designed for outdoor
installation.
The ACAH chiller series includes two (2) scroll compressors to form
two (2) refrigerant cycles. Up to five (5) chillers can be interlocked
through LG’s CH3 A and B 2-wire control bus.
LG includes inverter technology in its scroll compressors and air-
cooled condenser fan motors to provide efficient operation at high
loads and in all operating areas. ACAH chillers also feature electron-
ic expansion valves, evaporators with shell-and-tube heat exchang-
ers (connected to the chilled water side), and condensers with air-
cooled fin-and-tube heat exchangers. Each refrigerant cycle includes
check valves, electronic expansion valves, refrigerant check valves,
and strainers. Human Machine Interface (HMI) controllers, built
within the ACAH chiller itself, applies LG’s unique control logic to monitor all parameters controlling the operation. These parameters can be
controlled to improve operational efficiency, and can continuously supply chilled water by adjusting to the environment.
Cooling Cycle
ACAH chillers feature high-pressure type scroll compressors. The suction vapor is separated from the high-pressure discharge area, and the
motor is installed on the low-pressure vapor area. The motor and refrigerant storage are located in the low-pressure vapor area to increase
liquid compression reliability.
Because the suction refrigerant vapor cools the motor and flows onward to the compressor, a separate device to cool the compressor is not
required. Inside the system, oil to lubricate the compressor is mixed with the refrigerant, and both the oil and refrigerant discharges during
operation. Discharged compressor oil can reduce the heat transfer efficiency if a thick layer builds up on interior walls of the condenser and
evaporator, so a device to prevent the refrigerant and oil to be discharged together is installed.
This lubrication system ensures longer life for the compressor, improves compression sealing, and provides lower sound operation. The
condenser is designed with a V-shaped heat exchanger, and an electronic expansion valve is used for efficient control in all load conditions.
The controller in the chiller is an LG exclusive, and monitors the different sensors installed to provide product protection.
For continuous supply of water, LG chillers are equipped with maximum continuous operation functions, and also provide precision control
to supply the targeted water volumes. Protection devices will immediately stop the chiller if the operation malfunctions, or a condition limit is
reached. In case of an operation malfunction, the chiller controller will display error codes to the authorized LG service provider.
Figure 1: Example of an LG Chiller.
Fan Motor
Fin and Tube
Heat Exchanger
Main Controller Box
Sub-Controller
Box
Condenser
Cover
Side
Cover
Rope Support
Access
Forklift Access
INTRODUCTION
