Setting The Pre-Pressure Of The Expansion Vessel; Connecting The Water Circuit - Daikin EKHBH054BA Manuel D'installation

3 Using the table and instructions below, determine if the total
water volume in the installation is below the maximum allowed
water volume.
Installation Water volume
height
≤
(a)
74 gallons (280 l)
difference
≤
23 ft
No pre-pressure adjustment
(≤
required.
7 m)
Actions required:
• pre-pressure must be increased,
calculate according to "Calculating
>23 ft
the pre-pressure of the expansion
(>7 m)
vessel"
• check if the water volume is lower
than maximum allowed water volume
(use graph below)
(a) Installation height difference: height difference (ft)(m) between the highest point
of the water circuit and the unit. If the unit is located at the highest point of the
installation, the installation height is considered 0 ft (0 m).
Calculating the pre-pressure of the expansion vessel
The pre-pressure (Pg) to be set depends on the maximum
installation height difference (H) and is calculated as below:
Pg =(H /32+0.3)x14.5 psi
(psi) (ft)
Pg =(H /10+0.3) bar
(bar) (m)
Checking the maximum allowed water volume
To determine the maximum allowed water volume in the entire circuit,
proceed as follows:
1 Determine for the calculated
corresponding maximum water volume using the graph below.
2 Check that the total water volume in the entire water circuit is
lower than this value.
If this is not the case, the expansion vessel inside the unit is too small
for the installation.
40
2.5
35
30
2
25
1.5
20
15
1
10
0.5
4 4
0 . 3 .
0 10 20 30 40 50
5
. 3
0 50 100 150 200
2
0
maximum water volume
= pre-pressure
= maximum water volume
Example 1
The unit is installed 16.4 ft (5 m) below the highest point in the water
circuit. The total water volume in the water circuit is 26.4 gallons
(100 l).
In this example, no action or adjustment is required.
EKHBH/X054BA
Indoor unit for air to water heat pump system
4PW54216-1
>74 gallons (280 l)
Actions required:
• pre-pressure must be decreased,
calculate according to "Calculating
the pre-pressure of the expansion
vessel"
• check if the water volume is lower
than maximum allowed water volume
(use graph below)
Expansion vessel of the unit
too small for the installation.
pre-pressure (Pg)
[gallons]
60 70 80 90 100 110 120
7 4
[l]
250 300 350 400 450
Example 2
The unit is installed at the highest point in the water circuit. The total
water volume in the water circuit is 92.5 gallons (350 l).
Result:
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 = (H /32+0.3)x14.5 psi = (0/32+0.3)x14.5 psi = 4.4 psi
(psi) (ft)
Pg = (H /10+0.3) bar = (0/10+0.3) bar = 0.3 bar
(bar) (m)
The corresponding maximum water volume can be read from
the graph: approximately 108.0 gallons (410 l).
Since the total water volume (92.5 gallons (350 l)) is below the
maximum water volume (108.0 gallons (410 l)), the expansion
vessel suffices for the installation.

Setting the pre-pressure of the expansion vessel

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
lead to malfunction of the system. Therefore, the pre-pressure
should only be adjusted by a licensed installer.

Connecting the water circuit

Water connections must be made in accordance with local laws and
regulations and the outlook diagram delivered with the unit,
respecting the water in- and outlet.
the
NOTE Be careful not to deform the unit piping by using
excessive
Deformation of the piping can cause the unit to
malfunction.
If air, moisture or dust gets in the water circuit, problems may occur.
Therefore, always take into account the following when connecting
the water circuit:
Use clean pipes only.
Hold the pipe end downwards when removing burrs.
Cover the pipe end when inserting it through a wall so that no
dust and dirt enter.
Use a good thread sealant for the sealing of the connections.
The sealing must be able to withstand the pressures and
temperatures of the system.
When using non-brass metallic piping, make sure to insulate
both materials from each other to prevent galvanic corrosion.
Because brass is a soft material, use appropriate tooling for
connecting the water circuit. Inappropriate tooling will cause
damage to the pipes.
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
copper piping is used in the unit's internal water
circuit.
When using a 3-way valve in the water circuit.
It is very important to guarantee full separation
between domestic hot water and floor heating
water circuit.
When using a 3-way valve or a 2-way valve in the
water circuit, the maximum change over time of
the valve shall be less than 60 seconds.
force when connecting the
Installation manual
piping.
15