Siemens RDG20 KN Series Basic Documentation page 95

4.7.9.2 Chilled/heated ceiling with pressure independent
Principle
A6V11545892_en--_c
combi valve (PICV) and 6-port ball valve for
changeover (RDG26..KN)
The RDG26..KN is able to control a PICV for a chilled and heated ceiling
application together with a 6-port ball valve for changeover.
This application is only available, if the thermostat is set to a 4-pipe with 6-port ball
valve as changeover and PICV application (DIP1 & DIP4 = On, see Applications for
universal systems [➙ 44]).
This application is used for chilled and heated ceilings (4-pipes) with one heat
exchanger and differential pressure controller (using a PICV).
The control sequences (heating and cooling) are managed by one DC 0...10 V
signal (Y10), to be used with a combi valve.
A 6-port ball valve must be used for changeover.
Enable the flow limitation function (for PICV) via parameter P256 to balance
heating and cooling and avoid hydraulic problems caused by the different flow
rates (see Additional functions [➙ 47]).
T[℃] Room temperature
Y10 DC 0...10 V signal
W Room temperature
setpoint
Control sequences
YH Control command "Valve" (heating)
YC Control command "Valve" (cooling)
P256 Flow limitation function for heating only
Functions
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