5 Preparation
Installer reference guide
9
07C2V3
ROTEX HPSU monobloc compact outdoor unit
4P501827-1 – 2017.08
▪
Closed circuit.
Use the outdoor unit ONLY in a closed water
system. Using the system in an open water system will lead to
excessive corrosion.
▪
Piping length.
It is recommended to avoid long runs of piping
between the domestic hot water tank and the hot water end point
(shower, bath,…) and to avoid dead ends.
▪
Piping diameter.
Select the water piping diameter in relation to
the required water flow and the available external static pressure
of the pump. See
"12 Technical data" on page 20
for the external
static pressure curves of the outdoor unit.
▪
Water flow.
It is required to guarantee a minimum flow of 13 l/min.
When the flow is lower, the system will stop operation and display
error 7H.
Minimum required flow rate
05+07 models
13 l/min
▪
Field supply components – Water and glycol.
Only use
materials that are compatible with the water (and, if applicable,
glycol) used in the system, and with the materials used in the
outdoor unit.
▪
Field supply components – Water pressure and temperature.
Check that all components in the field piping can withstand the
water pressure and water temperature.
▪
Water pressure.
The maximum water pressure is 3 bar. Provide
adequate safeguards in the water circuit to ensure that the
maximum pressure is NOT exceeded.
▪
Water temperature.
All installed piping and piping accessories
(valve,
connections,…)
MUST
withstand
the
following
temperatures:
Water circuit
Water temperature
Space heating
65°C
Domestic hot water
89°C
▪
Drainage – Low points.
Provide drain taps at all low points of the
system in order to allow complete drainage of the water circuit.
▪
Drainage – Pressure relief valve.
Provide a proper drain for the
pressure relief valve to avoid water coming into contact with
electrical parts.
▪
Air vents.
Provide air vents at all high points of the system, which
must also be easily accessible for servicing. The outdoor unit has
a manual air purge valve. The backup heater (option) has an
automatic air purge valve. Check that automatic air purge valves
are NOT tightened too much, so that the automatic release of air
from the water circuit is possible.
▪
Zn-coated parts.
Never use Zn-coated parts in the water circuit.
Because the unit's internal water circuit uses copper piping,
excessive corrosion may occur.
▪
Non-brass metallic piping.
When using non-brass metallic
piping, insulate the brass and non-brass properly so that they do
NOT make contact with each other. This to prevent galvanic
corrosion.
▪
Filter.
It is strongly recommended to install an additional filter on
the heating water circuit. Especially to remove metallic particles
from foul heating piping, it is recommended to use a magnetic or
cyclone filter, which can remove small particles. Small particles
may damage the unit and will NOT be removed by the standard
filter of the heat pump system.
▪
Thermostatic mixing valves.
In accordance with the applicable
legislation, it may be necessary to install thermostatic mixing
valves.
▪
Hygienic measures.
The installation must be in compliance with
the applicable legislation and may require additional hygienic
installation measures.
▪
Recirculation pump.
In accordance with the applicable
legislation, it may be required to connect a recirculation pump in
between the hot water end point and the recirculation connection
of the domestic hot water tank.
c
d
a
b
a
Recirculation connection
b
Hot water connection
c
Shower
d
Recirculation pump
NOTICE
Be sure to install the filter properly. Failure to install or
incorrect installation will damage the plate heat exchanger
permanently.
5.3.2
Formula to calculate the expansion vessel
pre-pressure
The pre-pressure (Pg) of the vessel depends on the installation
height difference (H):
Pg=0.3+(H/10) (bar)
5.3.3
To check the water volume and flow rate
The outdoor unit has an expansion vessel of 7 litre with a factory-set
pre-pressure of 1 bar.
To make sure that the unit operates properly:
▪ You must check the minimum and maximum water volume.
▪ You might need to adjust the pre-pressure of the expansion
vessel.
Minimum water volume
Check that the total water volume in the installation is minimum
20 litre, the internal water volume of the outdoor unit NOT included.
INFORMATION
In critical processes, or in rooms with a high heat load,
extra water might be required.
NOTICE
When circulation in each space heating/cooling loop is
controlled by remotely controlled valves, it is important that
the minimum water volume is guaranteed, even if all of the
valves are closed.
Maximum water volume
NOTICE
The maximum water volume depends on whether glycol is
added to the water circuit. For more information on the
addition of glycol, refer to the installation manual of the
HPSU monobloc tank.
Use the following graph to determine the maximum water volume for
the calculated pre-pressure.
