Siemens RDG20 KN Series Basic Documentation page 88

4
Functions
Control sequences
4.7.6.2 4-pipe/2-stage heating and cooling (RDG2..KN)
Heating and cooling
mode
Limit number of outputs
On/Off output
Note
88 | 186
In 4-pipe/2-stage applications, the thermostat controls max. 4 valves in heating and
cooling mode or heating/cooling mode by manual selection. Heating and cooling
mode (P001 = 4) is factory-set.
st
The 1 stage is activated when the acquired temperature is below (heating) or
above (cooling) the setpoint.
nd
The 2 stage is activated when the acquired room temperature exceeds the
"setpoint differential" value.
In heating and cooling mode, the 1
activated at same time.
For applications with only 1-stage heating or 1-stage cooling, the number of
controlled outputs can be set to 3 via P200 (limit number of heating/cooling
sequence) accordingly.
The diagrams below show the control sequence for On/Off control.
RDG26..KN can not be set as On/Off control output and is fixed as DC control
output.
Heating and cooling mode (P001 = 4)
Heating mode with manual selection
(P001 = 3) or
save energy (P010 = 2 & P014) in
heating sequence
T[°C] Room temperature
w Room temperature setpoint
X Dead zone (P055)
dz
w Setpoint differential (P056)
D
st nd
and 2 stage for heating or cooling can be
Cooling mode with manual selection
(P001 = 3) or
save energy (P010 = 2 & P015) in
cooling sequence
YH1, YC1 Control command
"Valve" stage 1
YH2, YC2 Control command
"Valve" stage 2
SDH Switching differential "Heating"
(P051)
SDC Switching differential "Cooling"
(P053)
A6V11545892_en--_e