20
Installation
4
GB
<Table 4.3.1>
* If the water flow rate is less than 7.1 L/min, the flow switch will be activated.
If the water flow rate exceeds 27.7 L/min, the flow speed will be greater than 1.5 m/s,
which could erode the pipes.
Water Circulation Pump Characteristics
Pump speed can be selected by main controller setting (see <Figure 4.3.4 -
4.3.7>).
Adjust the pump speed setting so that the flow rate in the primary circuit is appro-
priate for the outdoor unit installed (see Table 4.3.1). It may be necessary to add
an additional pump to the system depending on the length and lift of the primary
circuit.
<Second pump >
If a second pump is required for the installation please read the following care-
fully.
If a second pump is used in the system it can be positioned in 2 ways.
The position of the pump influences which terminal of the FTC4 the signal cable
should be wired to. If the additional pump(s) have current greater than 1A please
use appropriate relay. Pump signal cable can either be wired to TBO.1 1-2 or
CNP1 but not both.
Option 1 (Space heating only)
If the second pump is being used for the heating circuit only then the signal cable
should be wired to TBO.1 terminals 3 and 4 (OUT2). In this position the pump can
be run at a different speed to the hydrobox’s in-built pump.
Option 2 (Primary circuit DHW and space heating)
If the second pump is being used in the primary circuit between the hydrobox and
the outdoor unit (Package system ONLY) then the signal cable should be wired to
TBO.1 terminals 1 and 2 (OUT1). In this position the pump speed
must
match
the speed of the hydrobox’s in-built pump.
Note: Refer to 5.2 Connecting inputs/outputs.
sizing Expansion Vessels
Expansion vessel volume must fit the local system water volume.
To size an expansion vessel both for the heating and cooling circuits the following
formula and graph can be used.
When the necessary expansion vessel volume exceeds the volume of an built-in
expansion vessel, install an additional expansion vessel so that the sum of the
volumes of the expansion vessels exceeds the necessary expansion vessel
volume.
* For installation of an EHSC-*M*EB model, provide and install an expansion
vessel in the field as the model does not come fitted with an expansion vessel.
V =
ε
× G
1 −
P¹ + 0.098
P² + 0.098
Where;
V : Necessary expansion vessel volume [L]
ε : Water expansion coefficient
G : Total volume of water in the system [L]
P¹
: Expansion vessel setting pressure [MPa]
P²
: Max pressure during operation [MPa]
Graph to the right is for the following values
ε : at 70 °C = 0.0229
P¹
: 0.1 MPa
P²
: 0.3 MPa
*A 30% safety margin has been added.
0
0
5
10
15
20
25
50
100
150
200
250
300
350
400
Expansion vessel sizing
Expansion vessel volume [L]
System water volume [L]
<Figure 4.3.3>
Outdoor heat pump unit
Water flow rate range [L/min]
Packaged
PUHZ-W50
7.1 - 14.3
PUHZ-W85
10.0 - 25.8
PUHZ-HW112
14.4 - 27.7
PUHZ-HW140
17.9 - 27.7
Split
PUHZ-RP35
7.1 - 11.8
PUHZ-RP50
7.1 - 17.2
PUHZ-RP60
8.6 - 20.1
PUHZ-(H)RP71
10.2 - 22.9
PUHZ-(H)RP100
14.4 - 27.7
PUHZ-(H)RP125
17.9 - 27.7
PUHZ-RP140
20.1 - 27.7
PUHZ-SW40
7.1 - 11.8
PUHZ-SW50
7.1 - 17.2
PUHZ-SW75
10.2 - 22.9
PUHZ-SW100
14.4 - 27.7
PUHZ-SW120
20.1 - 27.7
PUHZ-SHW80
10.2 - 22.9
PUHZ-SHW112
14.4 - 27.7
PUHZ-SHW140
17.9 - 27.7
