STRA-14 Room controller. Installation and maintenance manual.
Fläkt Woods
8710 GB 2016.09.08
5 (12)
Specifications are subject of alteration without further notice.
Operating modes
STRA-14 has five different operating modes. Through
the Function button you are able to switch between three
of them. These are set through the parameter menu
(parameter 45) in the display. Occupied is the preset
mode.
Off
Operating mode Off means that the controller is switched
off, i.e. heating and cooling are disabled. However,
the temperature may not drop below the set minimum
temperature (parameter 6, FS = 8°C). If it does, the
controller will start heating. The background lighting
on the display is not lit, and only OFF is shown in the
display.
Nozzle setting for the airflow is according to Energy
Saving mode (Parameter 306).
Display: The background lighting is not lit, and only OFF
is shown in the display.
Unoccupied (Energy Saving Mode)
Operating mode Unoccupied is an energy saving mode. It
means that the room where the controller is placed is not
used for an extended period of time, for example during
evenings, nights or weekends. The controller is prepared
to change the operating mode to Occupied if someone
enters the room (presence). Both heating and cooling are
disabled within a temperature interval with configurable
min/max temperatures (parameter 4 respectively 5, FS
min = 19°C, max = 27°C).
Nozzle setting for the airflow is according to Energy
Saving mode (Parameter 306) but is increased step by step
if the cooling water valve is fully open and there is still a
need for increased cooling.
The background lighting on the display is not lit, but the
current room temperature (or setpoint value depending
on the configuration) is shown in the display. OFF is
shown in the display for this operating mode as well.
Standby (Energy Saving Mode) STELLA,
WEGA and NOVA
Operating mode Stand-by means that the room is in
an energy saving mode and is not used at the moment.
This can be during evenings, nights, weekends etc. The
room temperature is controlled around the applicable
heating and cooling setpoint values, with an extended
temperature interval (FS = +/-3°C).
Nozzle setting for the airflow is according to Energy
Saving mode (Parameter 306) but is increased step by step
if the cooling water valve is fully open and there is still a
need for increased cooling.
For example, if the heating setpoint value is 22°C and the
cooling setpoint value is 24°C, the controller will allow
the temperature in the room to be between 19°C and 27°C.
Local adjustment of setpoint value via the display on
STRA-14.
The background lighting on the display is lit (dimmed)
and STANDBY with the current room temperature (or
setpoint value depending on the configuration) are shown
in the display. Learn more in section Occupancy detector.
Occupied (Normal Mode)
Operating mode Occupied means that the room is in
use and is therefore in a comfort mode. The controller
regulates the room temperature around a heating
setpoint value and a cooling setpoint value (parameter 1
respectively 2, FI heating setpoint value = 22°C, cooling
setpoint value = 24°C). Nozzle setting for the airflow
is according to Normal mode (parameter 307) but is
increased step by step if the cooling water valve is fully
open and there is still a need for increased cooling. The
setpoint values can also be ad/-3°C locally via the
display, or via a central command.
The background lighting on the display is lit (dimmed),
and the occupancy indication is shown (see the Display
handling section). The current room temperature (or
setpoint value depending on the configuration) is shown
in the display.
Bypass (Boost Mode) STELLA, WEGA and
NOVA
Operating mode Bypass means that the controller controls
the room temperature in the same way as in operating
mode Occupied. For the chilled beam this activates the
output for forced ventilation and the air flow goes to a
predetermined maximum position (parameter 308). After
a configurable time (parameter 12, FS = 60 minutes) the
controller automatically returns to the preset operating
mode. Boost is normally activated when the Occupancy
button is pressed or a central command. The operating
mode is useful for example in conference rooms, where
many people are present at the same time during a
limited period of time.
The background lighting on the display is lit (dimmed).
The occupancy indication and the symbol for forced
ventilation are shown (see the Display handling section
on page 3). The current room temperature (or setpoint
value depending on the configuration) is shown in the
display.
Activation of operating modes
Preset operating mode
Occupied is the preset operating mode. Configuration of
desired operating mode is done in the parameter menu
on the display (parameter 45). The operating mode is
changed at following events:
• When the Occupancy button is pressed
• Activation/deactivation of an occupancy detector
• Via central control, for example central time control,
central booking system etc.
