Device Protection Unit; Water Pipe Connection - LG Multi V ARWN Series Installation Manual

• Always install a strainer (50Mesh or above) at the entrance of the
water pipe. (When sand, trash, rusted pieces get mixed into the
water supply, it can cause problems to the product due to block-
ing)
- If On/Off valve is applied, by interlocking with outside unit, it can
save the energy consumption of pump by blocking the water
supply to the outside unit not operating. Select appropriate valve
and install on site if necessary.
• Install a pressure gauge and temperature gauge at the inlet and
outlet of the water pipe.
• Flexible joints must be installed not to cause any leakage from the
vibration of pipes.
• Install a service port to clean the heat exchanger at the each end
of the water inlet and outlet.
• For the components of the water pipe system, always use com-
ponents above the designed water pressure.
Pressure gauge Temperature gauge
Water pipe
outlet
Gate valve Service port
Water pipe
Inlet
Gate valve
Service port
! CAUTION
Do not directly connect the drain outlet to the water pipe outlet.
(It can cause problems to the product.)

Water pipe connection

• The water pipe should be the same size of the connection on the
product or more.
• If necessary install the insulation material in the water pipe
inlet/outlet to prevent water drop, freeze and to save energy.
(Use the above 20mm thickness PE insulation material.)
• Tightly connect the socket to the water pipe refer to below table
for recommended specification.
(Too much torque may cause the damage of the facility.)
Pipe thickness Shear stress Tensile stress
mm inch (kN) (kgf) (kN)
12.7 1/2 3.5 350
19.05 3/4 12 1200
25.4 1 11.2 1120
31.8 1 1/4 14.5 1450 6.5
38.1 1 1/2 16.5 1.7
50.8 2 21.5 2.2 13.5
Strainer
Condensed
Drain line
water drain
Bending
Torque
moment
(N . m) (kgf . m) (N . m)
(kgf)
2.5 250 20 23 5
2.5 250 20 2 115
4 400 45 4.5 155
650 87.5 8.75 265
9.5 0.95 155 16 350
1.4 255 26 600
Water pipe outlet
Water pipe
connection
Water pipe inlet

DEVICE PROTECTION UNIT

Strainer on water pipe
To protect the water cooling type product, you must install a strainer
with 50 mesh or more on the heat water supply pipe.
If not installed, it can result in damage of heat exchanger by the follow-
ing situation.
1
Heat water supply within the plate type heat exchanger is com-
posed of multiple small paths.
2
If you do not use a strainer with 50 mesh or more, alien particles
can partially block the water paths.
3
When running the heater, the plate type heat exchanger plays the
role of the evaporator, and at this time, the temperature of the
coolant side drops to drop the temperature of the heat water sup-
ply, which can result in icing point in the water paths.
4
And as the heating process progresses, the water paths can be par-
tially frozen to lead to damage in plate type heat exchanger.
5
As a result of the damage of the heat exchanger from the freezing,
the coolant side and the heat water source side will be mixed to
make the product unusable.
1. Pollution of
Heat source
Heat Source
Water
Head loss of strainer on water pipe
60
50
45
30
15
0
0 30 60 90
I/min
ARWN100LAS4
Upper graph is a theoretical value for selection and it may be different
according to specification of strainer.
(kgf . m)
3.5
Flow switch work
11.5
15.5
• It is recommended to install the flow switch to the water collection
26.5
pipe system connecting to the outside unit.
35.5
(Flow switch acts as the 1st protection device when the heat water
61
is not supplied. If a certain level of water does not flow after in-
stalling the flow switch, an error sign of CH24 error will be displayed
on the product and the product will stop operating.)
• When setting the flow switch, it is recommended to use the product
with default set value to satisfy the minimum flow rate of this prod-
uct. (The minimum flow rate range of this product is 50%. Reference
flow rate : 10HP – 96LPM, 20HP – 192LPM
• Select the flow switch with the permitted pressure specification con-
sidering the pressure specification of the heat water supply system.
(Control signal from outside unit is AC 220V.)
2. Partially frozen
Refrigerant
: Suggestion range
: Allowed range
60
50
45
30
15
0
120 150
0 60 120
96
I/min
ARWN200LAS4
13
3. Damage
180 240 300
192