RDU20U, RDU50U and
RDU50.2U
Technical Instructions
Document No. 155-735
November 1, 2006
Room Temperature Controllers
with LCD for Heating and
Cooling Systems
RDU20U and RDU50U
RDU50.2U
Siemens Industry, Inc.
Description
The RDU Series Room Controller with LCD is designed for heating and cooling
systems.
Features
•
Modulating Propor Integral (P+I) control
•
Control depending on room or remote air temperature
•
Output for a 0 to 10 Vdc actuator (RDU50U and RDU50.2U)
•
Output for a floating (3-position) or on/off output actuator (RDU20U)
•
Adjustable actuator run time (RDU20U)
•
Automatic heating/cooling changeover (RDU20U and RDU50U)
•
Manual heating/cooling changeover (RDU50.2U)
•
Operating modes: Normal, Energy Saving and Off
•
Operating mode changeover input for remote control
•
Selectable installation and control parameters
•
Adjustable minimum limitation for cooling output
•
Optional selectable Direct Acting or Reverse Acting output
•
Selectable display of room temperature or setpoint
•
Fahrenheit or Celsius selectable
•
Minimum and maximum setpoint limitation
•
Operating voltage, 24 Vac
Application
•
Individual room temperature control in heating or cooling HVAC applications.
•
Control of that are heated or cooled.
Product Numbers
Table 1.
Product Numbers
Features
RDU20U
Automatic heating/cooling changeover
RDU50U
Automatic heating/cooling changeover
RDU50.2U
Manual heating/cooling changeover switch
