STRA-07 Room Controller. Installation and maintenance manual.
STRA-07 for Fancoils
Fläkt Woods
8713 GB 2014.04
9
Specifications are subject of alteration without further notice.
Shutdown
When the Occupancy button is held depressed for more
than 5 seconds, the controller changes operating mode to
”Shutdown” (Off/Unoccupied), regardless of the current
operating mode. Via the display , you can configure
which operating mode, Off or Unoccupied, should be
activated on ”Shutdown”. The factory setting is that
Unoccupied is activated.
If you press the Occupancy button for less than 5 seconds
when the controller is in operating mode Shutdown
or the preset operating mode, the controller changes
to operating mode Bypass. If you press the button for
less than 5 seconds when the controller is in Bypass, it
changes operating mode to the Preset operating mode.
After a configurable time in Bypass (FS=2 hours), the
controller returns to the preset operating mode.
For handling of the Occupancy button in combination
with central control, see the section Central control below.
Occupancy detector
For local control of the operating mode between the
preset operating mode and Bypass, an occupancy detector
is connected.
When occupancy is indicated, the controller changes
operating mode to Bypass. If you want to be able to
enter the room temporarily without activating Bypass,
for example to pick something up, you can configure a
powerup delay. This means that Bypass is not activated
until the power-up delay has expired. The Bypass delay
can be set to a value between 0 and 60 minutes (FS=0
min).
In Bypass on presence, there is a switch-off timer, which
means that if there is no occupancy indication during this
time (FS=10 min), the controller will return to the preset
operating mode.
Control states
The controllers can be configured for different control
states/control sequences:
• Heating
• Heating or cooling via the change-over function
• Heating/Heating
• Heating/Cooling
• Heating/Cooling with VAV-control and forced supply
air function
• Heating/Cooling with VAV-control
• Cooling
• Cooling/Cooling
For the control states, UO1 is used for the left control
function and UO2 is used for the right control function.
For control states where only one control function is
active (Heating, Heating or cooling via the change-over
function, and Cooling), only UO1 is used.
Heating
In control state Heating, the unit is always a heating
controller and controls according to the heating setpoint
plus/minus the setpoint displacement. The setpoint can be
adjusted in the display.
Heating or cooling via the change-over function
Like control state Heating but with change-over function,
i. e. when the change-over input is active, the controller
becomes a cooling controller and regulates according
to the basic cooling setpoint plus/minus the setpoint
displacement. See more in the section Change-over.
Heating/Heating
Split output signal
In control state Heating/Heating, the controller is always
a heating controller and controls according to the basic
heating setpoint plus the setpoint displacement. When
the controller output signal reaches 50%, it is divided
between two actuators. 0…48% of the signal is sent to
actuator 1 and 52…100% of the signal is sent to actuator 2.
See the figure below.
Heating/Cooling
In control state Heating/Cooling, the controller functions
as a heating controller when the room temperature
is lower than the basic heating setpoint plus half the
neutral zone. The neutral zone is the difference in
temperature between the heating setpoint and the cooling
setpoint. When the room temperature exceeds this limit,
the controller becomes a cooling controller. There is a
hysteresis of 0.1°C when the controller changes from
heating to cooling controller and vice versa. When the
controller is heating, it regulates according to the basic
heating setpoint plus the setpoint displacement, and
when it is cooling according to the basic cooling setpoint
plus the setpoint adjustment.
