50 | LOOP CIRCUIT DESIGN
LOOP CIRCUIT DESIGN | 51
W
ater Loop Circuit Design
Multi V W
ater 5 575V 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.
WATER CIRCUIT INSTALLATION
Piping System Specifications
Flow Switch, continued.
• The flow switch must be installed at the horizontal pipe of the water source unit's heat
water-supply outlet. Verify the direction of the water flow before installation. (Picture 1)
• Remove the jumper wire and connect to the communication terminals (4[A] and 4[B]) of
the water source unit's control box. (Pictures 2, 3) Open the flow switch cover and check
the wiring diagrams before connecting the wires. Wiring methods can vary by flow switch
manufacturer.
• If necessary (and after consulting with an LG representative), use the flow rate detection
contact to adjust flow rate to within the minimum range. (Picture 4)
Minimum flow rate range of this product is 50%. Adjust the flow switch to the contact
point when the flow rate reaches 50%. Minimum flow rate range is 50%. When installing
the Variable Water Flow Control Kit, set minimum water flow to 40% of nominal flow rate.
• If the unit operates while the flow switch contact point is out of the
permitted range, it can result in performance deterioration or system failure.
• A normally open type of flow switch must be used.
Figure 17: Flow Switch Install Steps.
Picture 1
Picture 2
Picture 3
Picture 4
Picture 3
4(N)
5(A)
5(B)
Picture 2
Picture 1
The information contained in this sec-
tion is intended for use by an indus-
try-qualified, experienced, certified
electrician familiar with the NEC who
is equipped with the proper tools and
test instruments.
Failure to carefully read and follow all
instructions in this manual can
result in personal injury or death.
All electric work must be performed
by a licensed electrician and con-
form to local building codes or, in the
absence of
local codes, with the NEC, and the
instructions given in this manual.
If the power source capacity is inadequate or
the electric work is not performed properly,
it may result in fire, electric shock, physical
injury or death.
Refer to local, state, and federal
codes, and use power wires of suffi-
cient current capacity and rating.
Wires that are too small may generate heat
and cause a fire, and physical injury or
death.
Secure all field wiring connections
with appropriate wire strain relief.
Improperly securing wires will create undue
stress on equipment power lugs. Inadequate
connections may generate heat, cause a
fire, and physical injury or death.
Ensure the system is connected to a
dedicated power source that provides
adequate power.
If the power source capacity is inadequate or
the electric work is not performed properly,
it may result in fire, electric shock, physical
injury or death.
Properly tighten all power connec-
tions.
Loose wiring may overheat at connection
points, causing a fire, physical injury or
death.
Do not change the settings of the
protection devices.
If the protection devices have been by-
passed or is forced to operate improperly,
or parts other than those specified by LG
are used, there is risk of fire, electric shock,
explosion, and physical injury or death.
WARNING
WATER CIRCUIT INSTALLATION
Pipe Insulation
Water pipe insulation is suggested in the following conditions:
• Where water pipe is subject to freezing.
• Water pipe where water can condense on surface of pipe from ambient room temperatures higher than temperature of water in the pipe. If
water temperature is maintained at 68°F in winter and 86°F in summer, insulation will not be required.
• On boiler water pipes to save energy losses from heat source.
• On condensate drain lines.
• Where required by local code.
Piping System Specifications
Device Protection Details
Strainer on Water Pipe
To protect the water source unit, a strainer with ≥50
mesh must be installed on the water source unit inlet
piping. If not installed, the heat exchanger can be
damaged by particles in the water supply.
1. The water-supply circuitry within the plate-type heat
exchanger is comprised of many small paths /
channels.
2. If a strainer with 50 mesh or more is not included,
foreign particles can partially block the water flow.
3. When the system operates in heating, the plate-
type heat exchanger functions as an evaporator,
therefore, the temperature of the coolant supply
drops the temperature of the heat-source water
supply, which can result in ice forming in the water circuitry.
4. As heating operation progresses, the channels can be partially frozen, which may damage the plate-type heat exchanger.
5. If the heat exchanger is damaged, the coolant supply and the heat source water supply will mix, and the system will not function.
Flow Switch
• It is recommended to install a flow switch on the water pipes that are connected to the WSU.
• Flow switch must be rated for 208-230V and be a normally open type. Flow switch will perform as the
first protection device when heated water is not supplied. If the required water level is not present
after installing the flow switch, the water source unit will display a CH24 error code and will stop
operating.
• When setting the flow switch, it is recommended to use the default set value of the water source unit
to satisfy the minimum flow rate. Minimum flow rate range is 50%. When installing the Variable Water
Flow Control Kit, set minimum water flow to 40% of nominal flow rate.
• Select a flow switch following the pressure specification of the water supply system.
1 inch or
3/4 inch
socket
Cover
Micro-switch
Adjustment screw
Vibration plate
Bellows
Pad
• If the set value does not satisfy the minimum flow rate, or if the set value is changed by the user
arbitrarily, it can result in performance deterioration or system failure.
• If the water source unit operates with a hard water supply, the heat exchanger can be damaged or
system failure can occur.
• If the water source unit displays a CH24 or CH180 error code, it is possible that the interior of the
plate-type heat exchanger is partially frozen. If this occurs, resolve the partial freezing issue and then
operate the water source unit again. Causes of partial freezing may be insufficient heat water flow rate,
water not supplied, insufficient coolant, foreign particles inside plate-type heat exchanger.
Heat Source
(Water)
Refrigerant
1. Scale and mineral deposits
2. Partially frozen
3. Damage
(cross contamination)
Figure 15: Potential Heat Exchanger Damage.
Figure 16: Flow Switch Schematic.