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Siemens
RDG400KN,RGD405KN Basic documentation
CE1P3192en
Building Technologies
2017-02-17
∂
The diagrams only show the PI controller’s proportional part
∂
Switching between heating and cooling depends on the setpoints and the room
temperature (see section 3.6.2)
Setting the sequence and the control outputs
Refer to sections 0, 3.6.1 and 3.7.
3.6.6 Single-duct applications with electric heater
General rule: In case of insufficient air flow, the thermostat cannot protect the
electric heater against overtemperature. For this reason, the heater
must
be
equipped with a separate safety device (thermal cutout).
On single-duct applications with electric heater, the thermostat controls a valve
plus an electric heater. P01 is not available.
The output signal for the air flow can be limited to a minimum and maximum value
if required using P63 and P64. On applications "Single-duct with electric heater",
the minimum value of P63 is overridden, so that the air flow never drops below
10% while the electric heater is in operation.
The air flow starts to rise depending on the acquired room temperature, the current
supply air temperature (if available) and the setpoint.
The electric heater receives an
On
command when the acquired room temperature
drops below the setpoint (= setpoint for electric heater).
Remote enabling/disabling of the electric heater is possible via input X1 or D1 for
tariff regulations, energy savings, etc.
Input X1 or D1 must be commissioned accordingly (P38, P42) (see section 3.8).
The electric heater can also be enabled/disabled via bus.
If input "Enable electric heater" is used via bus, the function
must not
be assigned
to a local input X1 or D1.
On start-up of the controller and if the primary controller sends the information that
the primary fan is off, the thermostat disables the electric heater (see section
3.10.9).
To avoid overheating of an electric heater when switched off, the air flow signal of
Vmin must be maintained for a preset "Fan overrun time" (P54, factory setting
60 seconds).
In connection with a Synco primary controller it will be ensured that the primary fan
keeps running during the fan overrun time (also refer to section 3.10.10).
Notes
Caution
Electric heating,
active in cooling mode
Digital input "Enable
electric heater"
KNX
R
Enable electric heater
Note
Fan overrun time
