User manual

25
ENGLISH
11) Water scale may occur on the plate type heat exchanger depending on the water quality and the type of plate heat
exchanger so regular chemical cleaning is necessary. When installing water pipes, install a heat source water shut-o
valve and also install the ushing pipe with a ball valves (for chemical cleaning) on the pipe installed between the
shut-o valve and the outdoor unit.
12) Before trial operation, connect the cleaning pipes installed on inlet and outlet as shown in above illustration. Then,
take appropriate measures (such as blind ange etc) to stop the circulation water from entering the outdoor unit
plate type heat exchanger, and use circulating pump to remove foreign substance within the water pipes and clean
the strainer. If you do not clean the strainer, foreign substances may accumulates on plate type heat exchanger and
may break the heat exchanger or cause problem to it.
13) Make sure that water quality within the water pipe meets the standard of cooling water quality for refrigerating and
air conditioning equipment.
- Heat source water containing high level of foreign substances can cause water heat exchanger and pipe corrosion
or creation of water scale. (Use the appropriate heat source water according to the below table)
- If the make-up water is provide from any other source than local water supply, make sure to check the quality of
water.
- Strainer (which needs to be purchased separately) must be installed to the ‘Water IN’ pipes of the water pipe. If
sand, dust or rust debris enters to water system, it may cause corrosion on metallic materials or blockage of the
water heat exchanger and damage the heat exchanger.
- If the existing thermal storage tank or pipes are used, foreign substances may block the plate type heat exchanger
of the DVM Hydro unit / Hydro unit HT so, water quality and foreign substances must be managed.
14) Check that the total water volume in the installation, excluding the internal water volume of DVM Hydro unit / Hydro
unit HT, is 20L minimum.
Section Item
Closed circuit system Eects
Recommended
number for water
quality inspection
Heat source
water
Make-up water Corrosion Scale
Standard
value
pH[25 ˚C] 7.0 ~ 8.0 7.0 ~ 8.0 O O
Once a year
Electric conductivity [25 ˚C]
(mS/m)
30 and below 30 and below O O
Chloride ion (mg Cl
-
/L) 50 and below 50 and below O
Sulfate ion (mg S0
4
2-
/L) 50 and below 50 and below O
M alkali level [pH 4.8](mg CaCo
3
/L) 50 and below 50 and below O
Total hardness (mg CaCo
3
/L) 70 and below 70 and below O
Calcium hardness (mg CaCo
3
/L) 50 and below 50 and below O
Ionized silica (mg SiO
2
/L) 30 and below 30 and below O
Reference
Iron (mg Fe/L) 1.0 and below 0.3 and below O O
Copper (mg Cu/L) 1.0 and below 1.0 and 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 and below 0.1 and below O
Residual chlorine (mg Cl/L) 0.25 and below 0.3 and below O
Free carbon dioxide (mg CO
2
/L) 0.4 and below 0.4 and below O
Stability index - - O O