Minimum Internal System Water Volume; Water Control - Hitachi RCUE40AG1 Installation, Operation And Maintenance Instructions

6.4. MINIMUM INTERNAL SYSTEM WATER VOLUME

To ensure the cooling operation at least 5 minutes without
interruption, the internal chilled water volume in the piping
system should be greater than the minimum volume as
shown below.
MODEL RCUE AG1
Minimum
m³
Internal Water Volume
Internal
litre 10.8 13.3 16.1 16.1 23.9 30.7 38.2 38.2 44.0 54.3 54.3 76.4 76.4 82.2 82.2 114.6 114.6
Volume in Water Cooler

6.5. WATER CONTROL

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CAUTION:
When industrial water is applied for chilled water and
condenser water, industrial water rarely causes
deposits of scales or other foreign substances on
equipment. However, well water or river water may in
most cases contain suspended solid matter, organic
matter, and scales in great quantities. Therefore,
such water should be subjected to filtration or
softening treatment with chemicals before application
as chilled water.
The following is the recommended standard water quality.
Item
Standard Quality
pH (25 °C)
Electrical Conductivity (mS/m) (25°C)
(2)
{µS/cm} (25 °C)
Chlorine Ion (mg CI¯/I)
Sulphur Acid Ion (mg SO
The Amount of Acid Consumption (pH 4.8)
(mg CaCO /I)
3
Total Hardness (mg CaCO
Calcium Hardness (mg CaCO
Silica L (mg SIO /I)
2
Reference Quality
Total Iron (mg Fe/I)
Total Cupper (mg Cu/I)
2
Sulphur Ion (mg S ¯/I)
Ammonium Ion (mg NH
4
Remaining Chlorine (mg CI/I)
Floating Carbonic Acid (mg CO
Index of Stability
NOTE:
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1. The mark " " in the table means the factor
concerned with the tendency of corrosion or deposits
of scales.
{}
2. The value showed in "
according to the former unit.
40 50 60 70 80
0.64 0.58 0.70 0.78 1.28 1.16 1.40 1.56 1.74 2.10 2.34 2.80 3.12 3.50 3.90 4.20 4.68
Circulating Water
(20 ° ° ° ° C Less than)
6.8 ~ 8.0
Less than 40
Less than 400
Less than 50
2
¯/I) Less than 50
4
Less than 50
/I) Less than 70
3
/I) Less than 50
3
Less than 30
Less than 1.0
Less than 1.0
+
/I) Less than 1.0
Less than 0.3
/I) Less than 4.0
2
6.8 ~ 8.0
" are for reference only
NOTE:
Minimum internal system water volume written above is
for standard ON/OFF differential, minimum internal
system water volume shall be increased by the setting of
differential.
100 120 140 150 180 200 240 270 300 330 360 400
It is also necessary to analyse the quality of water by
checking pH, electrical conductivity, ammonia ion
content, sulphur content, and others, and to utilise
industrial water only if problem is encountered
through these check.
Chilled Water System
Supply Water
6.8 ~ 8.0
Less than 30
Less than 300
Less than 50
Less than 50
Less than 50
Less than 70
Less than 50
Less than 30
Less than 0.3
Less than 0.1
It shall not be detected.
Less than 0.1
Less than 0.3
Less than 4.0
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INSTALLATION
6
(1)
Tendency
Deposits of
Corrosion
Scales
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