13. X9A socket
The X9A socket receives the thermistor connector (only for
installations with domestic hot water tank).
14. Pump fuse FU2 (in line fuse)
15. Pump relay K4M
16. Transformer TR1
17. A4P
Solar/remote alarm input/output PCB (only for installations with
solar kit or remote alarm kit).
18. K7M relay for solar pump (optional)
This relay and its output on X2M can be activated when the solar
input on A4P becomes active.
19. Conduit hole to pass through the booster heater power supply
cable.
20. Conduit hole to pass through the booster heater power supply
cable and the thermal protection cabel.
21. Conduit hole to pass through the room thermostat cable and
2-way valve and 3-way valve control cables.
22. Conduit hole to pass through the thermistor cable and user
interface cable (and benefit kWh rate cable).
23. Conduit hole to pass through the backup heater power supply
wiring.
24. Conduit hole to pass through optional input/output PCB
connection wiring.
The electrical wiring diagram can be found on the
NOTE
inside of the switch box cover.
Water pipework
All piping lengths and distances have been taken into consideration.
Requirement
Maximum allowable distance between the 3-way valve and
the unit (only for installations with domestic hot water tank).
Maximum allowable distance between the domestic hot
water tank and the unit (only for installations with domestic
hot water tank). The thermistor cable supplied with the
domestic hot water tank is 12 m in length.
NOTE
If the installation is equipped with a domestic hot water
tank (optional), please refer to the domestic hot water
tank installation manual.
In case of a power supply failure or pump operating failure,
drain the system (as suggested in the figure below).
A
When water is at standstill inside the system, freezing up is
very likely to happen and damaging the system in the
proces.
E(D/B)(H/L)Q011~016AA6V3+W1
Unit for air to water heat pump system
4PW51121-1A
Value
3 m
10 m
<A
Checking the water circuit
The units are equipped with a water inlet and water outlet for
connection to a water circuit. This circuit must be provided by a
licensed technician and must comply with all relevant European and
national regulations.
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.
Before continuing the installation of the unit, check the following
points:
The maximum water pressure is 3 bar.
Drain taps must be provided at all low points of the system to
permit complete drainage of the circuit during maintenance.
A drain valve is provided in the unit to drain the water from the
unit water system.
Air vents must be provided at all high points of the system. The
vents should be located at points which are easily accessible for
servicing. An automatic air purge is provided inside the unit.
Check that this air purge valve is not tightened too much so that
automatic release of air in the water circuit remains possible.
Take care that the components installed in the field piping can
withstand the water pressure.
Checking the water volume and expansion vessel
pre-pressure
The unit is equipped with an expansion vessel of 10 litre which has a
default pre-pressure of 1 bar.
To assure proper operation of the unit, the pre-pressure of the
expansion vessel might need to be adjusted and the minimum and
maximum water volume must be checked.
1
Check that the total water volume in the installation, excluding
the internal water volume of the unit, is 20 l minimum. Refer to
"Technical specifications" on page 32 to know the internal water
volume of the unit.
In most applications this minimum water volume will have a
satisfying result.
In critical processes or in rooms with a high heat load
though, extra water volume might be required.
When circulation in each space heating loop is controlled
by remotely controlled valves, it is important that this
minimum water volume is kept even if all the valves are
closed.
Example
1
2
3
4
1
Unit
2
Heat exchanger
3
Pump
4
Shut-off valve
5
Collector (field supply)
6
By-pass valve
(field supply)
I
5
6
T1
T2
T3
M1
M2
M3
FHL1
FHL2
FHL3
FHL1..3 Floor heating loop
(field supply)
T1..3
Individual room
thermostat (field supply)
M1..3
Individual motorised
valve to control loop
FHL1 (field supply)
I
User interface
Installation manual
10