1
3
. Installation
NOTE
• Circle (O) marks in the chart show the factor relevant to corrosion or water scale.
• When the water temperature is over 40 ˚C (104 ˚F), steels without protective coating may corrode
when exposed to water. Appl ng corrosion prevention material or degassing can be effective
measure to prevent corrosion.
• For the cooling water and the make-up water, used under closed circuit water system with closed
circuit cooling tower, should satisfy the standard shown in above table.
• Supplied water or make-up water should be tap water, industrial water. Purified water,
neutralized water and softened water should not be supplied.
• 15 items in the above table is a typical factor for corrosion and/or water scale.
• When water pipe circuit freezes, it will cause breakage on the plate type heat exchanger.
Therefore appropriate preventive measure must be taken according to the situation.
−
Drain remaining water in the water pipe
−
Constantly operate the water pump to circulate the water within the water pipe
−
Install a self-regulating heat cable on the water pipe
• Open the valve of the water pipe connected to the outdoor unit after flushing (cleaning foreign
substances in water pipe) is completed.
• Check that air is vented from the water pipe and circulation amount is secured before opening the
service valve on the refrigerant side of the outdoor unit.
• If water flow stops during outdoor unit operation, it may cause breakage on plate type heat
exchanger.
Classification
Item
Closed type system
Effects
Recommended
number for water
quality inspection
Circulating water
Supplemented
water
Corrosion
Scale
Standard
value
pH [25 °C (77 °F)]
7 .0 ~ 8 .0
7 .0 ~ 8 .0
O
O
Once a year
Electric conductivity
[25 °C (77 °F)] (mS/m)
30 or below
30 or below
O
O
Chloride ion (mg Cl-/L)
50 or below
50 or below
O
Sulfate ion (mg S0
4
2
-/L)
50 or below
50 or below
O
O
M alkali level [pH 4 .8]
(mg CaCo
3
/L)
50 or below
50 or below
O
Total hardness (mg CaCo
3
/L)
70 or below
70 or below
O
Calcium hardness
(mg CaCo
3
/L)
50 or below
50 or below
O
Ionized silica (mg SiO
2
/L)
30 or below
30 or below
O
Reference
Iron (mg Fe/L)
1 .0 or below
0 .3 or below
O
O
Copper (mg Cu/L)
1 .0 or below
1 .0 or below
O
Sulfate ion (mg S
2
-/L)
Not to be
detected
Not to be
detected
O
Ammonium ion (mg NH
4
+/L)
0 .3 or below
0 .1 or below
O
Residual chlorine (mg Cl/L)
0 .25 or below
0 .3 or below
O
Free carbon dioxide
(mg CO
2
/L)
0 .4 or below
0 .4 or below
O
Stability index
-
-
O
O
