Rotex HPSU Bi-Bloc Ultra Series Installer's Reference Manual page 58

8 Configuration
Control
Define how the operation of the unit is controlled.
Control
Leaving water Unit operation is decided based on the leaving
water temperature regardless the actual room
temperature and/or heating or cooling demand
of the room.
External room Unit operation is decided by the external
thermostat thermostat or equivalent (e.g. heat pump
convector).
Room thermostat Unit operation is decided based on the ambient
temperature of the user interface used as a
room thermostat.
# Code
[2.9] [C‑07] ▪ 0: Leaving water
▪ 1: External room thermostat
▪ 2: Room thermostat
Thermostat type
Only applicable in external room thermostat control.
NOTICE
If an external room thermostat is used, the external room
thermostat will control the room frost protection. However,
the room frost protection is only possible if [C.2] Space
heating/cooling=On.
# Code
[2.A] [C‑05] External room thermostat type for the
main zone:
▪ 1: 1 contact: The used external room
thermostat can only send a thermo
ON/OFF
separation between heating or cooling
demand. The room thermostat is
connected to only 1 digital input
(X2M/35).
Select this value in case of a
connection to the heat pump convector
(FWXV).
▪ 2: 2
room thermostat can send a separate
heating/cooling
condition. The room thermostat is
connected to 2 digital inputs (X2M/35
and X2M/34).
Select this value in case of a
connection to the wired (RKRTWA) or
wireless (RKRTR1) room thermostat
Leaving water temperature: Delta T
In heating for the main zone, the target delta T (temperature
difference) depends on the selected emitter type for the main zone.
The difference delta T indicates, depends on the operation mode:
▪ In heating mode, delta T indicates the temperature difference
between the leaving water setpoint and entering water.
▪ In cooling mode, delta T indicates the temperature difference
between entering and leaving water temperature.
The unit is designed to support underfloor loops operation. The
recommended leaving water temperature for underfloor loops is
35°C. In such case, the unit will realize a temperature difference of
5°C, which means that the entering water temperature is around
30°C.
Installer reference guide
58
In this control...
Description
Description
condition. There is no
contacts: The used external
thermo ON/OFF
Depending on the installed type of heat emitters (radiators, heat
pump convector, underfloor loops) or situation, you can change the
difference between entering and leaving water temperature.
Note: : The pump will regulate its flow to keep the delta T. In some
special cases, the measured delta T can differ from the set value.
INFORMATION
When only the backup heater is active in heating, delta T
will be controlled according to the fixed capacity of the
backup heater. It is possible that this delta T is different
from the selected target delta T.
INFORMATION
In heating, the target delta T will only be achieved after
some operation time, when the setpoint is being reached,
because of the big difference between leaving water
temperature setpoint and inlet temperature at startup.
INFORMATION
If the main zone or the additional zone has a heating
demand, and this zone is equipped with radiators, then the
target delta T that the unit will use in heating operation will
be 10°C fixed.
If the zones are not equipped with radiators, then in
heating the unit will give priority to the target delta T for the
additional zone, if there is a heating demand in the
additional zone.
In cooling the unit will give priority to the target delta T for
the additional zone, if there is a cooling demand in the
additional zone.
# Code
[2.B.1] [1‑0B] Delta T heating: A minimum
temperature difference is required for
proper operation of heat emitters in
heating mode.
▪ If [2-0C]=2, this is fixed to 10°C
▪ Else: 3°C~10°C
Delta T cooling: A minimum
[2.B.2] [1‑0D]
temperature difference is required for
proper operation of heat emitters in
cooling mode.
▪ 3°C~10°C
Leaving water temperature: Modulation
Only applicable in case of room thermostat control.
When using the room thermostat functionality, the customer needs
to set the desired room temperature. The unit will supply hot water to
the heat emitters and the room will be heated.
Additionally, also the desired leaving water temperature must be
configured: if Modulation is enabled, the unit automatically
calculates the desired leaving water temperature. These calculations
are based on:
▪ the preset temperatures, or
▪ the desired weather-dependent
dependent is enabled)
Moreover, with Modulation enabled, the desired leaving water
temperature is lowered or raised in function of the desired room
temperature and the difference between the actual and the desired
room temperature. This results in:
▪ stable room temperatures,
temperature (higher comfort level)
▪ less on/off cycles (lower noise level, higher comfort and higher
efficiency)
Description
temperatures (if weather-
exactly matching the desired
RRGA04~08DAV3 + RHBX04+08DA
ROTEX HPSU Bi-Bloc Ultra
4P495262-1B – 2019.10