2-Stage On 2-Pipe/4-Pipe Heating And Cooling - Siemens RDG20 KN Series Basic Documentation

4.7.6 2-stage on 2-pipe/4-pipe heating and cooling

2-stage heating or cooling
Fan in the 2 stage
nd
Limit number of
heating/cooling sequence
A6V11545892_en--_c
In 2-stage applications, the thermostat controls 2 valves or 2-stage compressors in
series:
●
2-pipe/2-stage: in heating or cooling mode or changeover (automatically or
manually). "Cooling only" is factory-set (P001 = 1)
●
4-pipe/2-stage: in heating and cooling mode or changeover (manually).
"Heating and cooling" is factory-set (P001 = 4)
Depending on the equipment, fan control needs to be started in the 2
st
the 1 stage, the fan remains Off) either in the heating or cooling sequence. To
cover the requested application, the fan can be enabled and disabled in different
sequences via P350. For further details, see Fan control [➙ 108].
In the 2-stage application (2-/4-pipe), with parameter P200 "number of
heating/cooling sequences", the number of outputs can be set to one cooling
sequence (P200 = 2) or one heating sequence (P200 = 3).
P200 = 1 (default)
P200 = 2
P200 = 3
2 sequence heating, 2 sequence cooling
2 sequence heating, 1 sequence cooling
1 sequence heating, 2 sequence cooling
Functions
4
Control sequences
nd
stage (in
83 | 180