Water Circuit Requirements - Daikin VRV W T-Series Installation Manual

4 Preparation
Item
(a)
Ionic-state silica (mg SiO /l)
2
Reference items
Iron (mg Fe/l)
Copper (mg Cu/l)
Sulfate ion (mg S /l)
2–
Ammonium ion (mg NH /l)
+
4
Residual chlorine (mg Cl/l)
Free carbon dioxide (mg CO /l)
2
Stability index
(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.
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.
4 .4 .2

Water circuit requirements

INFORMATION
Also read the precautions and requirements in the
"General safety precautions" chapter.
NOTE
Use water pipes compiled with the local and national codes.
▪ The water pressure resistance of water piping of this outside unit
is 464 psig (3.2 MPa).
▪ The connection port for water piping is located in the front. The
connection ports for drain piping are located in the front and back.
When using the back port, change the cast iron plug from the back
to the front and securely close it.
▪ In indoor use, piping work should be such that no water drops on
the outer plate.
▪ The lateral protruding section of the drain piping should be short
(within 15-3/4 inch (400 mm)) and installed in a downward
direction.
The diameter of drain pipe should be the same as the diameter of
unit connection (3/8 inch (9.5 mm)) or more.
▪ The diameter of water pipe should be the same as the diameter of
unit connection (1-1/4 inch (31.8 mm)) or more.
▪ Install an air purge valve in the midway of the water piping to
prevent cavitation.
▪ After completing the drain piping work, make sure that the water
runs smoothly without any clogging by dust.
▪ Do not connect the drain outlet to the water outlet.
▪ Install a strainer (standard accessory) in the inlet of water piping
within a distance of 4.9 ft (1.5 m) from the outside unit.
(If sand, waste or rust particles are mixed in the water circulation
system, metal materials will become corrosive.)
Installation manual
16
Cooling water and
(b)
circulation system
Circulation Make-up
water water
<50 <30
<1.0 <0.3
<0.3 <0.1
—
<1.0 <0.1
<0.3
<4.0
6.0~7.0 —
▪ Install insulation on the inlet/outlet of water piping to prevent
condensation and freezing.
At installing insulation on water in/outlet pipe, use Polyurethane
foam thickness 3/16 inch (5 mm) for insulation of water piping
socket on heat exchanger.
▪ Install insulation up to the base of heat exchanger as shown in the
figure 6.
▪ Install a gate valve for chemical cleaning in an easy position to
handle.
▪ Use water pipes compliant with the local and national codes.
▪ Run the water pump to flush inside of water piping.
Then, clean the strainer.
▪ If there is a possibility of freezing, take measures to prevent
freezing.
▪ Connect water piping and heat exchanger via pipe adaptor
(accessory) (ISO228-1•G1-1/4B→ANSI-ASME B1.20.1•
1-1/4-11.5NPT)
▪ Tighten securely the connection of water piping and socket with
tightening torque of 220 ft·lbf (300 N·m) or less.
(If a large torque is applied, the unit may be damaged.)
Example:
a
b
Hot water system
(c)
Circulation Make-up
water water
(68~140°F)
(20~60°C)
<30
<1.0 <0.3
<1.0 <0.1
<0.3 <0.1
<0.25 <0.3
<0.4 <4.0
—
c
m
d
e
j
n
e
k
l
a Air purge (field supply)
b Water outlet
c Water inlet
d
Shut-off valve (field supply)
e Water connection
f Water piping (field supply)
g Insulation (field supply)
h Pipe adaptor (accessory)
i Heat exchanger
j Strainer (accessory)
k Drain valve (field supply)
l Drain connection
m
Insulation cover
n Flow switch (field supply)
VRV W T-Series water-cooled system air conditioner
Tendency
(d)
Corrosion Scale
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g
f h
i
RWEQ96~432TAYCU
4P540122-1B – 2018.11