Siemens RDG20 KN Series - Page 82

Functions
Control sequences
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A6V11545892_en--_e
In this case, an electric heater is connected directly to outputs Q2 (RDG26..KN),
and the current heats up the relay contact. This falsifies the internal temperature
sensor reading. The thermostat compensates the temperature, if the rated power
of the electric heating is entered at P217.
Factory setting P217: 0.0 kW, setting range: 0.0…1.2 kW.
The diagrams below show the control sequence for On/Off control.
Heating mode
(changeover = heating or heating only)
Cooling mode
(changeover = cooling or cooling only)
T[°C] Room temperature
SDH Switching differential "Heating"
(P051)
w Room temperature setpoint
SDC Switching differential "Cooling"
(P053)
YHC Control command "Valve"
X
dz
Dead zone (P055)
YE Control command
"Electric heater"
w
D
Setpoint differential (P056)
The diagrams below show the control sequence for modulating control.
Heating mode
(changeover = heating or heating only)
Cooling mode
(changeover = cooling or cooling only)
T[°C] Room temperature
XpH Proportional band "Heating"
(P050)
w Room temperature setpoint
XpC Proportional band "Cooling"
(P052)
YHC Control command "Valve"
X
dz
Dead zone (P055)
YE Control command
"Electric heater"
w
D
Setpoint differential (P056)
● The diagrams only show the PI thermostat’s proportional part.
For setting sequence and control outputs, see Application overview [➙ 43],
Sequence overview (setting via P001) [➙ 77] and Control outputs [➙ 101].
Parameter P256 (RDG264KN only), P260 & P261 (RDG26..) sets the
heating/cooling flow limitation. See Additional functions [➙ 48].
On/Off control
Control sequence
On/Off output
Modulating control:
3-position, PWM or
DC 0…10 V
Control sequence
modulating control output
Note
Note