9.4 WATER CONTROL
It is necessary to analyse the quality of water by checking pH,
electrical conductivity, ammonia ion content, sulphur content,
and others. The following is the recommended standard water
quality.
Item
Chilled water system
Tendency
(1)
Circulating
water (20ºC
less than)
Supply
water
Corro-
sion
Depos-
its of
scales
Standard Quality pH
(25 °C)
6.8 ~ 8.0
6.8 ~ 8.0
Electrical Conductivity
(mS/m) (25 °C)
{µS/cm} (25 °C)
(2)
Less than 40
Less than 400
Less
than 30
Less
than 300
Chlorine Ion
(mg CI
¯
/I)
Less than 50
Less
than 50
Sulphur Acid Ion
(mg H
2
SO
4
¯
/I)
Less than 50
Less
than 50
The amount of Acid
consumption (pH 4.8)
(mg CaCO
3
/I)
Less than 50
Less
than 50
Total Hardness
(mg CaCO
3
/I)
Less than 70
Less
than 70
Calcium Hardness
(mg CaCO
3
/I)
Less than 50
Less
than 50
Silica L (mg SIO
2
/I)
Less than 30
Less
than 30
Reference Quality
Total Iron (mg Fe/I)
Less than 1.0
Less
than 0.3
Total Copper
(mg Cu/I)
Less than 1.0
Less
than 0.1
Sulphur Ion (mg S
2¯
/I)
It shall not be detected
Ammonium Ion
(mg NH
4
+
/I)
Less than 1.0
Less
than 0.1
Remaining Chlorine
(mg CI/I)
Less than 0.3
Less
than 0.3
Floating Carbonic
Acid (mg CO
2
/I)
Less than 4.0
Less
than 4.0
Index of Stability
6.8 ~ 8.0
-
?
N O T E
• (1) The mark “ ” in the table means the factor concerned with the
tendency of corrosion or deposits of scales.
• (2) The value showed in “
{}
” are for reference only according to the
former unit.
9.5 WATER PIPING CONNECTION
Piping location and connection size
The unit is factory supplied with two unions to be connected to
the water inlet/outlet pipe. Refer to the next figure detailing the
location of the water pipes location, dimensions and connection
sizes.
Water inlet
Water outlet
Description
Connection size
Water Inlet
Rp1”
Water Outlet
Rp1”
9.6 SUSPENSION OF WATER PIPING
Suspend the water piping at certain points and prevent the
water piping from being in direct contact with the building: walls,
ceilings, etc…
If there is direct contact between pipes, abnormal sound may
occur due to the vibration of the piping. Pay special attention in
cases of short piping lengths.
Do not fix the water pipes directly with the metal fittings (piping
may expand and contract).
Some examples for suspension method are shown below.
For suspending
heavies
For piping along
the wall
For instant
installation work
10 ELECTRICAL AND CONTROL
SETTINGS
10.1 GENERAL CHECK
•
Make sure that the following conditions related to power
supply installation are satisfied:
-
The power capacity of the electrical installation is large
enough to support the power demand of the YUTAKI
system (outdoor unit + DHW tank (if apply)).
-
The power supply voltage is within ±10% of the rated
voltage.
-
The impedance of the power supply line is low enough
to avoid any voltage drop of more than 15% of the rated
voltage.
ELECTRICAL AND CONTROL SETTINGS
PMML0506 rev.2 - 01/2021
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