Siemens RDG20 KN Series Basic Documentation page 84

Functions
4
Control sequences
4.7.6.1 2-pipe/2-stage heating or cooling
Heating mode
Cooling mode
Limit number of outputs
Swap function
On/Off output
84 | 180
st
In heating mode, the 1
setpoint.
nd
The 2 stage is activated if the acquired room temperature drops below "setpoint"
minus "setpoint differential".
st
In cooling mode, the 1
setpoint.
The 2 nd stage is activated if the acquired room temperature exceeds "setpoint" plus
"setpoint differential".
For applications with 1-stage heating or 1-stage cooling only , the number of
controlled outputs is set via P200 (limit number of heating/cooling sequences).
With the swap function enabled, the 1
stage in cooling. This function optimizes use of heating/cooling energy in systems
with different equipment. E.g., fan coil units combined with radiant heating/cooling
panels or floor heating/cooling. See Additional functions [➙ 47] to enable the
function via P254.
The diagrams below show the control sequence for On/Off control.
Heating mode (P001 = 0)
Changeover (P001 = 2 or P001 = 3,
P254 = 0)
T[° C] Room temperature
w Room temperature setpoint
YHC1 Control command "Stage 1"
YHC2 Control command "Stage 2"
stage is activated if the acquired temperature is below the
stage is activated if the acquired temperature is above the
st stage in heating (YHC1) switches to the 2
Cooling mode (P001 = 1)
Changeover (P001 = 2 or P001 = 3,
P254 = 1) (swap function)
Changeove
r cooling
Changeove
r heating
SDH
SDC
w
D
Changeove
r cooling
(YHC2: 1
sequence)
Changeove
r heating
Switching differential "Heating"
(P051)
Switching differential "Cooling"
(P053)
Setpoint differential (P056)
A6V11545892_en--_c
nd
st