Siemens RDG20 KN Series - Page 86

Functions
Control sequences
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A6V11545892_en--_e
4.7.6.1 2-pipe/2-stage heating or cooling
In heating mode, the 1
st
stage is activated if the acquired temperature is below the
setpoint.
The 2
nd
stage is activated if the acquired room temperature drops below "setpoint"
minus "setpoint differential".
In cooling mode, the 1
st
stage is activated if the acquired temperature is above the
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
st
stage in heating (YHC1) switches to the 2
nd
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 [➙ 48] to enable the
function via P254.
The diagrams below show the control sequence for On/Off control.
Heating mode (P001 = 0)
Cooling mode (P001 = 1)
Changeover (P001 = 2 or P001 = 3,
P254 = 0)
Changeover (P001 = 2 or P001 = 3,
P254 = 1) (swap function)
Changeove
r cooling
Changeove
r cooling
(YHC2: 1
st
sequence)
Changeove
r heating
Changeove
r heating
T[°C] Room temperature
w Room temperature setpoint
YHC1 Control command "Stage 1"
YHC2 Control command "Stage 2"
SDH Switching differential "Heating"
(P051)
SDC Switching differential "Cooling"
(P053)
w
D
Setpoint differential (P056)
Heating mode
Cooling mode
Limit number of outputs
Swap function
On/Off output