10 | WSU PRODUCT DATA
WSU PRODUCT DATA | 11
W
ater Source Unit Product Data
MUL
TI V W
ater V W
ater Source Unit Engineering Manual
© LG Electronics Canada, Inc., North York, ON Canada. All rights reserved. “LG” is a registered trademark of LG Corp.
© LG Electronics Canada, Inc., North York, ON Canada. All rights reserved. “LG” is a registered trademark of LG Corp.
MECHANICAL SPECIFICATIONS
Refrigeration Oil Control
The oil return system uses the following technologies:
High Pressure Oil Return (HiPOR)
Oil is captured from compressor discharge by the centrifugal
oil separator and then returned to the compressor through
a separator oil injection pipe, preventing mixing of oil and
refrigerant on the suction side of the compressor.
Smart Oil Control
Smart oil control monitors the oil level inside the compressor
and initiates an oil return cycle to flush oil in the pipe system
back to the compressor only when the oil level is too low.
Timed oil return cycles are not necessary and the compressor
is protected from operating at oil levels that are too low.
Compressors
Each WSU frame is equipped with one hermetic, digitally-con-
trolled, inverter-driven scroll compressor to modulate capacity
(variable from 20 to 140Hz. The compressor has a built-in oil
level sensor to provide real-time oil control.
Heat Exchanger
The water heat exchanger is a stainless steel, type SUS316, refrigerant/water plate heat exchanger. The heat exchanger requires a
field-provided 50 mesh strainer and water treatment to prevent scaling inside the heat exchanger. Closed loop condenser water systems are
recommended to protect the factory-mounted heat exchanger.
Electrical
Multi V Water V 575V units are available in 575V, 60Hz, 3 Phase input power supply. All WSUs are capable of operating within voltage limits
of ±10% rated voltage, and include overcurrent protection.
Controls
Multi V Water V 575V units are factory wired with the necessary electrical control components, integral microprocessors, printed circuit
boards, thermistors, sensors, terminal blocks, and power lugs.
The control circuit between the indoor units, heat recovery units (Heat Recovery configuration only) and the WSU is an RS-485 daisy chain
communication bus. The cable is two conductor, stranded and shielded, 18 AWG.
Microprocessor-based algorithms provide component protection, soft-start capability, refrigeration system pressure and temperature control.
The variable water flow control kit allows condenser water temperatures below 59°F and works with condenser water pumps equipped with
variable frequency drive to save pumping energy.
For Heat Recovery Unit information, refer to the applicable Engineering Manual on
www.lgvrf.ca
MULTI V Water V Water Source Outdoor Units
Figure 4: Dual Frame MULTI V Water V Water Source Unit.
Multi V Water V 575V
Multi V Water V 575V water source units (WSU), equipped with an inverter compressor, offer superior load matching and long piping instal-
lation. The product optimizes power consumption in high-rise buildings. Add on features make it easy to upgrade the existing capacity at any
time. Sophisticated electronic control and unique refrigerant flow gives these systems the capability to perform in extreme/unusual working
conditions.
Generation 4 Equipment
The latest versions of LG’s indoor units and water source units are designated Generation 4 (Gen 4). For Gen 4 units to operate with Gen 4
features, the air conditioning system must meet the following requirements:
• All indoor units, heat recovery units, and water source units must be Gen 4.
• All water source units must have Gen 5 software installed.
• Water source units DIP switch 3 must be set to ON (factory default setting is OFF).
• All controllers must support Gen 4 features.
Low Sound Levels
When Multi V Water V 575V water source units operate fully loaded, they have one of the quietest sound levels in the industry. Sound is
almost undetectable during off-peak operation. To promote a quiet, comfortable environment, LG Multi V water source units operate at sound
levels as low as 47 dB(A) in cooling mode and 51 dB(A) in heating mode. LG customers often ask if the water source unit is running after
commissioning is complete.
All rotating components are soft-started by the controller using digitally controlled inverters, which reduces undesirable noise caused by
compressors cycling on and off.
Comfort Control at Its Best
Tight temperature control through precise load matching maximizes the time that the indoor units remove moisture. This ensures maximum
comfort and delivers the industry’s best indoor humidity levels.
Precision Load Matching
Unlike traditional air conditioning control systems, which use thermostatic controls to maintain room temperatures, LG Multi V Water V 575V controls
continuously vary the indoor unit fan speed and refrigerant flow, indirectly providing lower and more consistent humidity levels in the conditioned space.
The longer the indoor coil temperature is below the dew-point of the room with air moving across the coil, the less the space humidity level varies,
compared to technologies that cycle fans and compressors on and off multiple times per hour.
The water source unit varies the compressor speed as needed to maintain system operating pressure. As a result, the Multi V Water V 575V
system delivers precise space temperature control.
Advanced Compressor Technology
Oil Management
Oil migration is no longer a concern when choosing Multi V Water V 575V. An oil management system ensures a safe level of oil in the com-
pressor sump.
1. Smart oil system monitors oil sump levels to know when to inject oil into the compressor, eliminating the need for oil return cycles.
2. HiPOR™ oil return system minimizes oil mixing with refrigerant by separating oil at compressor discharge with an oil separator and
injecting oil back to the lower section of the compressor shell. Energy is saved by compressing the refrigerant without the oil mixed at the
compression chamber.
3. Oil injection system provides a consistent film of oil to moving parts, even at low speeds, ensuring compressor operation down to 20 Hz.
Inverter Driven
The scroll compressor is optimized to maximize compressor efficiency, which reduces power consumption and monthly utility bills. This
latest inverter technology allows the LG Multi V Water V 575V to vary the compressor motor shaft speed to deliver an appropriate amount of
cooling to all indoor units. Precise refrigerant volume delivery translates into long periods with coil surface temperatures below dew point and
minimizes compressor component run time. Occupants remain comfortable while utility costs are reduced.
PRODUCT FEATURES AND BENEFITS
MULTI V Water V Water Source Outdoor Units