Basic Documentation
Table Of Contents
- 1 About this document
- 2 Overview
- 3 Notes
- 4 Functions
- 4.1 Temperature control
- 4.2 Operating modes
- 4.3 Room temperature setpoint
- 4.4 Application overview
- 4.5 Additional functions
- 4.6 Control sequences
- 4.7 Control outputs
- 4.8 Fan control
- 4.9 Multifunctional input, digital input
- 4.10 Auto Timer
- 4.11 Handling system faults
- 4.12 Infrared remote control
- 4.13 Control parameters
- 5 Connection
- 6 Technical data
- 7 Dimensions
- Index
Functions
Control sequences
4
A6V12166490_en--_c
33 | 58
4.6.4 4-pipe fan coil unit
In 4-pipe applications, the thermostat controls 2 valves in heating and cooling
mode, heating/cooling by manual selection, or heating and cooling mode with
changeover. Heating and cooling (P01 = 4) is factory-set.
The heating or cooling output can be released via operating mode button if P01 is
set to Manual (P01 = 2).
The diagrams below show the control sequence for On/Off control.
Heating and cooling mode (P01 = 4)
T[°C] Room temperature
w Room temperature setpoint
YH Control command "Valve"
(heating)
YC Control command "Valve"
(cooling)
SDH Switching differential "Heating"
(P30)
SDC Switching differential "Cooling"
(P31)
X
dz
Dead zone (P33)
Heating mode with manual selection
(P01 = 2) or
for energy saving (P09 ≥ P10) in
heating sequence
Cooling mode with manual selection
(P01 = 2) or
for energy saving (P09 ≥ P10) in cooling
sequence
The diagrams only show the PI thermostat’s proportional part.
For setting sequence and control outputs, see Application overview [➙ 21],
Overview of sequences (setting via P01) [➙ 30] and Control outputs [➙ 36].
Heating and cooling
4-pipe application with
manual changeover
On/Off control
Note