10T8Y1B
VRV-W IV System Air Conditioner
4P399208-1 – 2015.01
Installation and operation manual
21
13.2. Before operation or starting a test run
Before starting a test run, please make sure that the piping work
has been carried out in a proper manner. Especially, make sure
that the filter, air purge valve, automatic water supply valve, and
expansion tank are positioned at their places correctly.
After the water circuit has been completely filled, first run the
pump only, and then make sure that no air has been caught in
the water circulation system and the water flow rate is correct. If
any air has been caught or the flow rate is not high enough, the
plate heat exchanger may freeze. Measure any water pressure
loss before and after the outdoor unit and make sure that the
flow rate is as designed. In case of any abnormality, stop the
pump immediately and carry out troubleshooting to resolve the
trouble.
Inspect the filter at the inlet piping of the outdoor unit. Clean it if it
is dirty.
13.3. Daily service and maintenance
Management of water quality
The plate heat exchanger has a structure that does not permit
dismantling and cleaning, or replacing any parts. Please pay
attention to the quality of water to be used for the plate heat
exchanger in order to prevent corrosion and scale.
The water to be used for the plate heat exchanger should have
at least the quality as specified in the following table.
When using corrosion prevention agents, scale depressant
agents, etc, such agents should not corrode stainless steel and
copper.
Management of chilled water flow rate
If the chilled water flow rate is not high enough, it will result in
freezing damage to the plate heat exchanger. Check for any
clogging of the filter, any air being caught, any reduction in the
flow rate due to failure of the circulation pump by measuring the
temperature and pressure differences at the inlet and outlet
ports of the plate heat exchanger. If the difference in the
temperature or pressure has increased beyond the allowed
range, this indicates that the flow rate has decreased. Stop the
operation and remove the cause before restarting operation.
Steps to be taken when the freezing protection device was
activated
When the freezing protection device was activated during
operation, eliminate the cause before restarting operation. If the
freezing protection device was activated once, a partial freezing
has occurred. If you restart operation without removing the
cause, the ice cannot be melted and the plate heat exchanger
will be blocked, resulting in damage to the plate heat exchanger,
which may cause the refrigerant to start leaking or water
entering the refrigerant circuit.
13.4. Water quality
Water quality standards for chilled water, hot water and make-up
water
(1)(2)
guideline
INFORMATION
Water quality must be in accordance with EU directive 98/
83 EC.
(1)
The supply water must be clean tap water, industrial water or clean
underground water. Do not use purified or softened water.
(2)
Once through water may cause corrosion. Do not use once through water.
Item
(a)
(a) These items represent typical causes of corrosion and scale.
Cooling water
system
(b)
(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.
Hot water system
(c)
(c) Corrosion has a tendency to occur when water temperature is high (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.
Tendency
(d)
(d) The circle marks in the columns indicate a tendency for corrosion or scale to
develop.
Circulation system
Circulation
water
Make-up
water
Circulation
water
(20°C ~
60°C)
Make-up
water
Corrosion
Scale
Standard items
pH (25°C)
6.5~8.2
6.0~8.0
7.0~8.0
7.0~8.0
○
○
Electrical
Conductivity
(mS/m)
(25°C)
<80
<30
<30
<30
○
○
Chloride ions
(mg cl
–
/l)
<200
<50
<50
<50
○
Sulfate ions
(mg SO
4
2–
/l)
<200
<50
<50
<50
○
Acid
consumption
(pH 4.8)
(mg CaCO
3
/l)
<100
<50
<50
<50
○
Total
hardness
(mg CaCO
3
/l)
<200
<70
<70
<70
○
Calcium
hardness
(mg CaCO
3
/l)
<50
<50
<50
<50
○
Ionic-state
silica
(mg SiO
2
/l)
<50
<30
<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
<0.3
<0.25
<0.3
○
Free carbon
dioxide
(mg CO
2
/l)
<4.0
<4.0
<0.4
<4.0
○
Stability index 6.0~7.0
—
—
—
○
○
