5 Application guidelines
Installer reference guide
21
RRLQ004~008CA + RHBH/X04+08CB
ROTEX HPSU low temperature Bi‑bloc
4P384979-1C – 2017.04
P
i
t
DI
a
b
P
i
Power input
t
Time
DI
Digital input (power limitation level)
a
Power limitation active
b
Actual power input
Setup and configuration
▪ No additional equipment needed.
▪ Set the power consumption control settings in [A.6.3.1] via the
user interface (for the description of all settings, see
"8 Configuration" on page 45
):
▪ Select full time limitation mode
▪ Select the type of limitation (power in kW or current in A)
▪ Set the desired power limitation level
NOTICE
Mind the following guidelines when selecting the desired
power limitation level:
▪ Set a minimum power consumption of ±3.6 kW to
guarantee defrost operation. Otherwise, if defrosting is
interrupted several times, the heat exchanger will
freeze up.
▪ Set a minimum power consumption of ±3 kW to
guarantee space heating and DHW production by
allowing at least one electrical heater (backup heater
step 1 or booster heater).
5.6.2
Power limitation activated by digital
inputs
Power limitation is also useful in combination with an energy
management system.
The power or current of the entire ROTEX system is limited
dynamically by digital inputs (maximum four steps). Each power
limitation level is set via the user interface by limiting one of the
following:
▪ Current (in A)
▪ Power input (in kW)
The energy management system (field supply) decides the activation
of a certain power limitation level.
Example:
To limit the maximum
power of the entire house (lighting, domestic appliances, space
heating…).
a
b
c
A
B
C
D
1
2
3
4
5
A8P
A
Outdoor unit
B
Indoor unit
C
DHW tank
D
Energy management system
a
Power limitation activation (4 digital inputs)
b
Backup heater
c
Booster heater
P
i
t
DI4
DI3
DI1
a
b
P
i
Power input
t
Time
DI
Digital inputs (power limitation levels)
a
Power limitation active
b
Actual power input
Setup
▪ Demand PCB (option EKRP1AHTA) needed.
▪ Maximum four digital inputs are used to activate the
corresponding power limitation level:
▪ DI1 = weakest limitation (highest energy consumption)
▪ DI4 = strongest limitation (lowest energy consumption)
▪ For the specifications of the digital inputs, and for where to
connect them, refer to the wiring diagram.
Configuration
Set the power consumption control settings in [A.6.3.1] via the user
interface (for the description of all settings, see
"8 Configuration" on
page 45
):
▪ Select activation by digital inputs.
▪ Select the type of limitation (power in kW or current in A).
▪ Set the desired power limitation level corresponding to each digital
input.
INFORMATION
In case more than 1 digital input is closed (at the same
time), the digital input priority is fixed: DI4 priority>…>DI1.
5.6.3
Power limitation process
The outdoor unit has better efficiency than the electrical heaters.
Therefore, the electrical heaters are limited and turned OFF first.
The system limits power consumption in the following order:
1
Limits certain electrical heaters.
If… has priority
Then set the heater priority
via the user interface to…
Domestic hot water production Booster heater.
Result:
The backup heater will
be turned OFF first.
Space heating
Backup heater.
Result:
The booster heater will
be turned OFF first.
2
Turns OFF all electrical heaters.
3
Limits the outdoor unit.
4
Turns OFF the outdoor unit.
Example
If the configuration is as follows:
▪ Power limitation level does NOT allow operation of both booster
heater and backup heater (step 1 and step 2).
▪ Heater priority = Booster heater.
Then power consumption is limited as follows:
