14
Outside Unit
Water control
Standard table for water purity control
The water may contain many foreign substances and hence may influence the performance and lifetime of the prod-
uct due to the corrosion of the condenser and water pipe. (Use water source that complies with the below standard
table for water purity control.)
If you use water supply other than the tap water to supply the water for the cooling tower, you must do a water quality
inspection.
•
If you use the closed cooling tower, the water quality must be controlled in accordance with the following standard
table.
If you do not control the water quality in accordance with the following standard water quality table, it can cause per-
formance deterioration to the air conditioner and severe problem to the product
[Reference]
(1) The "O" mark for corrosion and scale means that there is possibility of occurrence.
(2) When the water temperature is 40
°
C or above or when uncoated iron is exposed to the water, it can result in corro-
sion. Therefore adding anti-corrosion agent or removing the air can be very effective.
(3) In case of using the closed type cooling tower, the cooling water and supplementing water must satisfy the water quali-
ty criteria of closed type system in the table.
(4) Supplementing water and supplied water must be supplied with tap water, industrial water and underground water
excluding filtered water, neutral water, soft water etc.
(5) 15 items in the table are general causes of corrosion and scale.
Items
pH(25
°
C)
Conductivity[25
°
C](mS/m)
Chlorine ion(mg CI-/
l
)
Sulfuric acid ion(mg SO
2
-/
l
)
Acid demand[pH 4.8] (mg SiO
2
/
l
)
Total hardness(mg SiO
2
/
l
)
Ca hardness(mg CaCO
3
/
l
)
Ion silica(mg SiO
2
/
l
)
Fe(mg Fe/
l)
Copper(mg Cu/
l)
Sulfuric acid ion(mg S
2
/
l)
Ammonium ion(mg NH
4
/
l)
Residual chlorine(mg Cl/
l)
Free carbon dioxide(mg CO
2
/
l)
Stability index
7.0~8.0
Below 30
Below 50
Below 50
Below 50
Below 70
Below 50
Below 30
Below 1.0
Below 1.0
Must not be detected
Below 0.3
Below 0.25
Below 0.4
-
Below 0.3
Below 0.1
Must not be detected
Below 0.1
Below 0.3
Below 4.0
-
7.0~8.0
Below 30
Below 50
Below 50
Below 50
Below 70
Below 50
Below 30
O
O
O
O
-
-
-
-
O
O
O
O
O
O
O
O
-
-
-
-
-
O
O
O
-
O
O
O
O
O
Closed type
Basic Item
Reference Item
Effect
Circulating water
Supplemented water
Corrosion
Scale
4
+
