[b
ar
]
[p
si]
pr
e-
pr
es
su
re
1
2
■
1 15
20
A
B
■
C
■
■
■
■
■
■
■
■
■
Checking the maximum allowed water volume
Connecting the water circuit
To determine the maximum allowed water volume in the entire circuit,
Water connections must be made in accordance with the outlook
proceed as follows:
diagram delivered with the unit, respecting the water in- and outlet.
Determine for the calculated pre-pressure (Pg) the
corresponding maximum water volume using the graph below.
Be careful not to deform the unit piping by using excessive
force when connecting the piping. Deformation of the
Check that the total water volume in the entire water circuit is
piping can cause the unit to malfunction.
lower than this value.
If air, moisture or dust gets in the water circuit, problems may occur.
If this is not the case, the expansion vessel inside the unit is too small
Therefore, always take into account the following when connecting
for the installation.
the water circuit:
figure "Maxi mum all owed water volume"
Use clean pipes only.
40
■
Hold the pipe end downwards when removing burrs.
2.5
35
■
Cover the pipe end when inserting it through a wall so that no
dust and dirt enter.
2 30
■
Use a good thread sealant for the sealing of the connections.
1.5
25
The sealing must be able to withstand the pressures and
temperatures of the system.
20
■
When using non-brass metallic piping, make sure to insulate
both materials from each other to prevent galvanic corrosion.
0.5
10
C
B
A
■
Because brass is a soft
material, use appropriate tooling
0.3 4.4
0
5.3
10
0
20
50
30
100
40 50 60 70
74
80 90
150 200 250 300 350
maximum water volume
10
0
110
400
120
[gallons]
450
[l]
for connecting the water circuit.
Inappropriate tooling will cause
damage to the pipes.
= pre-pressure
= maximum water volume
= Sytem without glycol
= System with 25% propylene glycol without
domestic hot water tank
= System with 25% propylene glycol with
domestic hot water tank
NOTE
The unit is only to be used in a closed water
system. Application in an open water circuit can
lead to excessive corrosion of the water piping.
Never use Zn-coated parts in the water circuit.
Excessive corrosion of these parts may occur as
(Refer to "Caution: "Use of glycol"" on page 16)
copper piping is used in the unit's internal water
circuit.
Example 1
When using a 3-way valve in the water circuit.
The unit is installed 16.4 ft (5 m) below the highest point in the water
Preferably choose a ball type 3-way valve to
circuit. The total water volume in the water circuit is 26.4 gallons
guarantee full separation between domestic hot
(100 l).
water and floor heating water circuit.
In this example, no action or adjustment is required.
When using a 3-way valve or a 2-way valve in the
water circuit.
Example 2
The recommended maximum changeover time of
The unit is installed at the highest point in the water circuit. The total
the valve should be less than 60 seconds.
water volume in the water circuit is 92.5 gallons (350 l).
Result:
Protecting the water circuit against freezing
Since 92.5 gallons (350 l) is higher than 74.0 gallons (280 l), the
pre-pressure must be decreased (see table above).
The required pre-pressure is:
Pg
(psi)
= (H
(ft)
/32+0.3)x14.5 psi = (0/32+0.3)x14.5 psi = 4.4 psi
Pg
(bar)
= (H
(m)
/10+0.3) bar = (0/10+0.3) bar = 0.3 bar
The corresponding maximum water volume can be read from
Frost can cause damage to the hydraulic system. As this unit is
installed outdoors and thus the hydraulic system is exposed to
freezing temperatures, care must be taken to prevent freezing of the
system.
All hydraulic parts are insulated to reduce heat loss. Insulation must
be foreseen on the field piping.
the graph: approximately 108.0 gallons (410 l).
The unit is already equipped with several features to prevent freezing.
Since the total water volume (92.5 gallons (350 l)) is below the
The software contains special functions using pump and back
maximum water volume (108.0 gallons (410 l)), the expansion
up heater to protect the complete system against freezing.
vessel suffices for the installation.
This function will only be active when the unit is off.
Setting the pre-pressure of the expansion vessel
As extra safety, a heatertape is winded around the piping to
When it is required to change the default pre-pressure of the
expansion vessel (14.5 psi (1 bar)), keep in mind the following
guidelines:
■
Use only dry nitrogen to set the expansion vessel pre-pressure.
■
Inappropriate setting of the expansion vessel pre-pressure will
protect vital parts of the hydraulic system inside the unit.
This heatertape will only be active in case of an abnormal
situation concerning the pump and will only protect internal parts
of the unit. It can not protect field installed parts outside the unit.
Field heater tape must be foreseen by the installer.
lead to malfunction of the system. Therefore, the pre-pressure
However in case of power failure, above mentioned features can not
should only be adjusted by a licensed installer.
protect the unit from freezing.
If power failure can happen at times the unit is unattended, Daikin
recommends adding glycol to the water system. Refer to Caution:
"Use of glycol" on page 16.
Refer to "[4-04] Freeze protection function" on page 28.
EDLQ036~054B EBLQ036~054BA6VJU1
Installation manual
Unit for air to water heat pump system
4PW56182-1
15
