LG Multi V Water V ARWM072CAS5 Engineering Manual page 27

WATER DESIGN GUIDE
Piping System, continued
• Dielectric pipe unions to prevent the possibility of galvanic corrosion.
• Pressure gauge at inlet and outlet.
• Thermometers at inlet and outlet.
• Flexible connectors at inlet and outlet.
• Shutoff valves at the inlet and outlet to permit service of the WSU.
• Condensate drain trap per local code.
• Service port with hose connections at inlet and outlet to flush the WSU heat exchanger when isolated from the water loop system.
Other considerations:
• Inhibitors must be used in the water loop, especially if water temperature operates above 104°F.
• Maintain water quality requirements.
Figure 14: WSU Water and Refrigerant Connections Diagram
Water Inlet Water Outlet
Pipe Pipe
Gate Valve
Pressure
Gauge
Temperature
Gauge
Flow Switch
PT Service Port
(For Cleaning
Heat Exchanger)
Strainer
(50 Mesh)
Gate Valve
Note: Before startup, remove the factory jumper at the flow switch
terminals and install a field supplied flow switch.
© LG Electronics Canada, Inc., North York, ON Canada. All rights reserved. "LG" is a registered trademark of LG Corp.
48 | LOOP CIRCUIT DESIGN
Water Balancing Valve
Pressure
Gauge
Refrigerant Pipes
Temperature
Gauge
Dielectric
Pipe Union
Flex
Connector
Flex
Connector
Dielectric
Pipe Union
Freeze Protection
The piping system must be protected from freezing during winter conditions. Heating mode of the water source unit will reduce water loop
temperature. The addition of antifreeze may lower the performance of the water source unit due to reduced heat transfer and added pressure
drop. LATS system design software has options to add antifreeze and calculate reduced capacity. To manually calculate capacity reduction,
follow these steps:
1. Find the appropriate system cooling or heating correction factor in the following Table.
2. Multiply the cooling or heating correction factor by the water source unit capacity to find the NET water source unit capacity.
3. Apply the appropriate system pressure drop correction factor from the Table below and multiply by the water source unit pressure drop to
find the net water source unit pressure drop.
Table 28: Antifreeze Correction Factors
Antifreeze Type Item
10% 20%
Cooling 0.998 0.997
Methanol Heating 0.995 0.99
Pressure Drop 1.023 1.067
Cooling 0.996 0.991
Ethylenel Glycol Heating 0.993 0.985
Pressure Drop 1.024 1.068
Cooling 0.993 0.987
Propylene Glycol Heating 0.986 0.973
Pressure Drop 1.040 1.098
Water Quality Requirements
Impurities in the water can influence the performance and life expectancy of the water source unit. Use a local water treatment professional to
test and treat the water. Use inhibitors in the water loop, especially if the water temperature is operated above 104°F. Ensure all air is purged
from the system. Maintain the following levels:
Table 29: Water Test Levels
Item
Circulating Water
Basic Items:
pH [77° F] 7.0 ~ 8.0
Conductivity [77° F] mS/m
Below 30
Chlorine ions (mg Cl /L) Below 50
-
Sulfate ions (mg SO 2/L) Below 50
2
4
Acid consumption (pH4.8) (mgCaCO /L)
Below 50
3
Total Hardness (mg CaCO /L) Below 70
3
Calcium Hardness (mg CaCO /L) Below 50
3
Ionic-static silica (mg SiO /L)
Below 30
2
Reference Items:
Iron (mg Fe/L) Below 1.0
Copper (mg Cu/L) Below 1.0
Sulfate ion (mg SO /L) Must not be detected
2
4
Ammonium ion (mg NH )L Below 0.3
+
4
Residual chlorine (mg CL/L) Below 0.25
Free carbon dioxide (mg CO /L) Below 0.4
2
Stability index
O = possibility of occurrence
© LG Electronics Canada, Inc., North York, ON Canada. All rights reserved. "LG" is a registered trademark of LG Corp.
WATER DESIGN GUIDE
Antifreeze % by weight
30% 40% 50%
0.995 0.993 0.992
0.985 0.979 0.974
1.091 1.122 1.160
0.987 0.983 0.979
0.997 0.969 0.961
1.124 1.188 1.263
0.98 0.974 0.968
0.96 0.948 0.935
1.174 1.273 1.405
Closed Type System Effect
Supplemented Water Corrosion
7.0 ~ 8.0 O
Below 30 O
Below 50 O
Below 50 O
Below 50 –
Below 70 –
Below 50 –
Below 30 –
Below 0.3 O
Below 0.1 O
Must not be detected O
Below 0.1 O
Below 0.3 O
Below 4.0 O
– – O
LOOP CIRCUIT DESIGN | 49
Scale
O
O
–
O
O
O
O
O
O
–
–
–
–
–
O