Installation and operation manual
14
HXY48TAVJU
VRV System indoor unit
3P616151-1A – 2021.12
7.2.4.
Water quality requirements
(a) These items represent typical causes of corrosion and scale.
(b) In a condenser water circuit that uses a closed cooling tower, the closed circuit circulating water and make-up water MUST meet the water quality standards for the hot water system,
and passing water and make-up water MUST satisfy those for the circulation type cooling water system.
(c) Corrosion has a tendency to occur when water temperature is high (104°F (40°C) or higher), and if metals with no protective coating are directly exposed to water, it would be a good
idea to take effective measures against corrosion such as adding a corrosion inhibitor or deaeration treatment.
(d) The circle marks in the columns indicate a tendency for corrosion or scale to develop.
7.2.5.
To insulate the water piping
The piping in the complete water circuit must be insulated to prevent
condensation during cooling operation and reduce capacity losses
during heating and cooling operations.
If the temperature is higher than 86°F (30°C) and the humidity is
higher than RH 80%, the thickness of the sealing materials should be
at least 0.8 inch (20 mm) to prevent condensation on the surface of
the sealing.
7.3.
Connecting the electrical wiring
7.3.1.
Precautions on electrical wiring work
Cooling water
(b)
and
circulation system
Hot water system
(c)
Tendency
(d)
Item
(a)
Circulation
water
Make-up
water
Circulation
water
(68~140°F)
(20~60°C)
Make-up
water
Corrosion
Scale
Standard items
pH (77°F (25°C))
6.5~8.2
6.0~8.0
7.0~8.0
○
○
Electrical conductivity (mS/ft (mS/m)) (77°F (25°C))
<24.4 (80)
<9.1 (30)
<9.1 (30)
○
○
Chloride ions (mg Cl
–
/l)
<200
<50
<50
○
Sulfate ions (mg SO
4
2–
/l)
<200
<50
<50
○
Acid consumption (pH 4.8) (mg CaCO
3
/l)
<100
<50
<50
○
Total hardness (mg CaCO
3
/l)
<200
<70
<70
○
Calcium hardness (mg CaCO
3
/l)
<150
<50
○
Ionic-state silica (mg SiO
2
/l)
<50
<30
<30
○
Reference items
Iron (mg Fe/l)
<1.0
<0.3
<1.0
<0.3
○
○
Copper (mg Cu/l)
<0.3
<0.1
<1.0
<0.1
○
Sulfate ion (mg S
2–
/l)
—
○
Ammonium ion (mg NH
4
+
/l)
<1.0
<0.1
<0.3
<0.1
○
Residual chlorine (mg Cl/l)
<0.3
<0.25
<0.3
○
Free carbon dioxide (mg CO
2
/l)
<4.0
<0.4
<4.0
○
Stability index
6.0~7.0
—
—
○
○
NOTE
The supply water MUST be clean tap water, industrial
water or clean underground water. Do NOT use
purified or softened water.
Do NOT use once-through water. It may cause
corrosion.
WARNING: Electrical Installation
All field wiring and components must be installed by an
installer and must comply with the applicable legislation.
NOTE
Electrical wiring work recommendations.
To persons in charge of electrical wiring work.
Do not operate the unit until the refrigerant piping is
complete. Running the unit before the piping is ready will
break the compressor.
WARNING
A main switch or other means for disconnection,
having a contact separation in all poles, must be
incorporated in the fixed wiring in accordance with the
applicable legislation.
Use only copper wires.
All field wiring must be carried out in accordance with
the wiring diagram supplied with the unit and the
instructions given below.
Never squeeze bundled cables and be sure that it
does not come in contact with the non-insulated
piping and sharp edges. Be sure no external pressure
is applied to the terminal connections.
Power supply wires must be attached securely.
Be sure to establish an earth. Do not earth the unit to
a utility pipe, surge absorber, or telephone earth.
Incomplete earth may cause electrical shock.
Be sure to install an earth leakage protector in
accordance with the applicable legislation. Failure to
do so may cause electric shock or fire.
Be sure to use a dedicated power circuit, never use a
power supply shared by another appliance.
Be sure to install the required fuses or circuit
breakers.
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