Electrical And Control Settings - Hitachi YUTAKI M RASM-2VRE Instruction Manual

ELECTRICAL AND CONTROL SETTINGS

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.
Chilled water system
Circulating
Item
water (20ºC
less than)
Standard Quality pH
6.8 ~ 8.0
(25 °C)
Electrical Conductivity
Less than 40
(mS/m) (25 °C)
Less than 400
{µS/cm} (25 °C)
(2)
Chlorine Ion
Less than 50
(mg CI /I)
¯
Sulphur Acid Ion
Less than 50
(mg H SO /I)
¯
2 4
The amount of Acid
consumption (pH 4.8) Less than 50
(mg CaCO /I)
3
Total Hardness
Less than 70
(mg CaCO /I)
3
Calcium Hardness
Less than 50
(mg CaCO /I)
3
Silica L (mg SIO /I) Less than 30
2
Reference Quality
Less than 1.0
Total Iron (mg Fe/I)
Total Copper
Less than 1.0
(mg Cu/I)
Sulphur Ion (mg S /I) It shall not be detected
2¯
Ammonium Ion
Less than 1.0
(mg NH /I)
+
4
Remaining Chlorine
Less than 0.3
(mg CI/I)
Floating Carbonic
Less than 4.0
Acid (mg CO /I)
2
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.
14 PMML0506 rev.2 - 01/2021
Tendency
(1)
Depos-
Supply Corro-
its of
water sion
scales
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
Less
than 0.1
Less
than 0.3
Less
than 4.0
-
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 outlet
Description
Water Inlet
Water Outlet
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 For piping along
heavies
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.
Water inlet
Connection size
Rp1"
Rp1"
For instant
the wall installation work