ABB i-bus KNX Product Manual page 3

1 F unction properties
0 B
The RTR-Fan Coil RTF/A 1.1 is a continuous KNX room thermostat for fan
convectors (Fan Coil) in 2 and 4 pipe systems.
It measures the current room temperature (actual value) and sends a
correcting variable
U H
required room temperature (set value).
The RTF/A 1.1 works both in heating mode and in cooling mode.
The fan stage can also be selected manually via a button.
Three binary inputs (see
buttons (floating) for switching, dimming or controlling venetian blinds.
The blind and dimmer channels can also be operated using a single button if
preferred (one-panel operation)
Alternatively, an external temperature sensor can be connected to input 3
(analogue).
To permit easy adjustment of the set values to meet the requirements for home
comfort and energy-saving, the RTF/A 1.1 supports four operating modes:
•
Comfort
•
Standby
•
Night mode
•
Antifreeze mode
A set value is assigned to each operating mode.
The comfort mode is used if there are persons in the room
In standby mode the set value is reduced slightly. This operating mode is used if the
room is not occupied but is expected to be occupied soon.
In night mode the set value is reduced further as the room is not expected to be
used for several hours.
In antifreeze mode, the room is regulated at a temperature that prevents damage to
the radiators due to freezing if the outside temperatures are very low.
This can be desirable for 2 reasons:
- The room will not be occupied for several days.
- A window has been opened and no heating is required temporarily.
The operating modes are generally controlled using a time switch.
For optimum control, however, presence watchdogs or presence buttons and window
contacts are recommended.
See also chapter C alculating the set value
H U
(0...100%), e.g. to an ABB i-bus® Fan Coil actuator to reach the
e xternal interface
H U
) can be used to connect switches or
U H
.
U H
c ontinuous
H U
3