LG Multi V Water IV Installation Manual page 80

WATER CIRCUIT INSTALLATION
Piping System Specifications
Device Protection Details
Strainer on Water Pipe
Install a strainer with ≥50 mesh on the water source unit inlet
piping to protect the water source unit. If the strainer is not
installed, the heat exchanger can be damaged by particles
in the water supply.
• The water-supply circuit in the plate-type heat exchanger
is comprised of many small paths / channels.
• If a strainer with 50 mesh or more is not included, foreign
particles can partially block the water flow.
• When the system operates in heating mode, the 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 circuit.
• As heating operation progresses, the channels can be partially frozen, which may damage the plate-type heat exchanger.
• 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 out pipe of the water source unit.
• The flow switch should be rated for 208-230V and be a normally closed type. The flow switch
is the first protection device when water flow is not supplied. If the required water flow is not
present after installing the flow switch, the water source unit displays error code CH24 and
stops operating.
• When setting the flow switch, set to 50% of the nominal flow rate of the WSU model. Refer
to the General Data Tables beginning on page 9 for the nominal flow rate. This flow switch
setting will satisfy the required minimum flow rate of 50%.
• If the Variable Water Flow Control Kit is also installed, set the flow switch minimum flow rate
to 40% of the nominal flow rate instead of 50%.
• Select a flow switch following the pressure specification of the water supply system.
Note:
• 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 partial freezing occurs, resolve the partial
freezing issue and then operate the water source unit again. Causes of partial freezing include
insufficient heat water flow rate, water not supplied, insufficient coolant, and foreign particles
inside the plate-type heat exchanger.
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Due to our policy of continuous product innovation, some specifications may change without notification.
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Figure 64: Potential Heat Exchanger Damage.
1. Scale and mineral deposits
Heat Source Refrigerant
(Water)
3. Damage
2. Partially frozen
(cross contamination)
Figure 65:Flow Switch Diagram.
Cover
Micro-switch
Adjustment screw
Vibration plate
Bellows
1 inch or
3/4 inch
socket
Pad