General Precautions Concerning Water Circuit - Rotex RKHBH008BB3V3 Manuel D'installation

6.8. General precautions concerning water circuit

Before continuing the installation of the unit, check the following
points:
■
The maximum water pressure is 4 bar.
■
The maximum water temperature during space heating is
(1)
65°C (safety device setting) and 75°C during domestic hot
water operation (safety device setting). Make sure that the
installed piping and piping
connections,...) can withstand the temperatures as shown in the
figure below.
75°C 75°C
65°C 65°C
T
1 2 3 4 5 6
6
1 Outdoor unit
2 Indoor unit
3 Heat exchanger
(2)
4 Backup heater
5 Pump
6 Shut-off valve
7 Motorised 3-way valve (field supply)
8 Motorised 2-way valve (field supply)
9 Collector (field supply)
10 Domestic hot water tank (optional)
(3)
11 Booster heater
12 Heat exchanger coil
FCU1...3 Fan coil unit (optional)
FHL1...3 Floor heating loop
T Room thermostat (optional)
■
Provide adequate safeguards in the water circuit to be sure that
the water pressure will never exceed the maximum allowable
working pressure (4 bar).
■
Two shut-off valves are delivered with the unit. To facilitate
service and maintenance, install one at the water inlet and one
at the water outlet of the indoor unit. Mind position of the shut-off
valves. Orientation of the integrated drain and fill valves is
important for servicing. See figure 3.
■
Drain taps must be provided at all low points of the system to
permit complete drainage of the circuit during maintenance.
Two drain valves integrated in the shut-off valves are provided to
drain the water from the indoor unit water system.
■
Make sure to provide a proper drain for the pressure relief valve
to avoid any water coming into contact with electrical parts.
(1) Be sure that the correct field settings are active or selected according to
the applicable tank type. See field settings in "[4] Backup/booster heater
operation and space heating off temperature" on page 28 for more details.
(2) For tank without electrical booster heater (RKHTS), the backup heater will
be used in domestic water heating mode.
(3) Only applicable for tank with built-in electrical booster heater (RKHW*).
Installation manual
15
accessories (e.g., valve,
65°C 65°C
(RKHTS) (RKHTS)
(RKHW*) (RKHW*)
FCU1
8
7
FCU2
FCU3
M M
FHL1
11 12
FHL2
FHL3
10
■
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 indoor
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 and water temperature.
■
Always use materials which are compatible with water used in
the system and with the materials used on the indoor unit.
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.
9
■
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.
■
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.
■
Select piping diameter in relation to required water flow and
available external static pressure of the pump.
■
The minimum required water flow for the indoor unit operation is
12 l/min. When the water flow is lower than this minimum value,
flow error 7H will be displayed and the operation of the indoor
unit will be stopped.
■
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.
NOTICE
It is strongly recommended to install an additional filter on
the heating water circuit. Especially to remove metallic
particles from the field heating piping, it is advised to use a
magnetic or cyclone filter which can remove small
particles. Small particles can damage the unit and will not
be removed by the standard filter of the heat pump unit.
RKHBH/X008BB
Indoor unit for air to water heat pump system
4PW62574-1 – 10.2010