Technical Instructions
RDF20U Room Temperature Controller with LCD
Document Number 155-334
for Two-Pipe Fan Coil Units with Electric Heat
September 27, 2007
Page 8
Siemens Industry, Inc.
Ordering
The QAH11.1 temperature sensor can be used as a return air temperature or
changeover sensor. The changeover sensor and the valves must be ordered
separately.
Equipment
Combinations
Table 2.
Product Number
Description
Technical Instructions
QAH11.1
Temperature Sensor
155-329P25
599 Series
Two-way and Three-way
Zone Valves
155-320P25
SF Series
Zone Valve Actuator
155-321P25
Mechanical Design
The controller consists of two parts:
▪
Plastic housing which accommodates the electronics, the operating elements and
the built-in room temperature sensor
▪
Base
The housing engages in the base and is secured with two screws. The base carries the
screw terminals. The DIP switches are located at the rear of the housing.
Setting and Operating
Elements
Figure 7. RDF20U Components.
1
Display of the room temperature, setpoints or control parameters
2
Symbol used when displaying the current room temperature
3
Normal mode
Economy mode
4
Cooling valve open
Fan on
Heating valve open
5
Buttons for adjusting the setpoints and the control parameters
6
Operating mode selector
(Standby “ ”, Heating or Cooling mode with manual selection of fan speed)
