User Manual

Siemens Building Technologies Application : 70 RWD82/70 – 04.2001

HVAC Products RWD82 1

RWD82/70

RWD82 Universal Controller

Application 70

Room temperature control

Chilled water control valve-3

24Vac control system

Control ( P or PI )

Room temperature control

Proportional control ( 3 position ) of the chilled water control valve

Optional day / night set point adjustment .

........RWD82.......

CCV

RWD82/70

CCV

Room temperature sensor

Time clock or switch

Opening output for CCV

Closing output for CCV

3 - position chilled water control valve.

Personal computer

Universal analogue input - main sensor

Auxiliary analogue input

Digital input

Digital output

Communication port

• Room temperature sensor can be selected as Ni1000, Pt1000, or active sensor.

• Adjustable proportional band of 3-position output Q1, Q2.

• Integral action function selection and adjustment.

• Timing of 3-position valve actuator

• 24Vac controller supply voltage

• 24Vac three position control valve

• Day / night set points can be selected via time clock or switch.

Supplemental features

Control

Operating modes

PAGE 1
RWD82/70 RWD82 Universal Controller Application 70 Room temperature control Chilled water control valve-3 pos 24Vac control system Control ( P or PI ) Room temperature control Proportional control ( 3 position ) of the chilled water control valve X1 S1 Q1 Q2 CCV PC Room temperature sensor Time clock or switch Opening output for CCV Closing output for CCV 3 - position chilled water control valve. Personal computer RWD82/70 Optional day / night set point adjustment .
PAGE 2
The temperature sensor senses the room conditions and on a rise in temperature the RWD82 via Q1, Q2 digital outputs modulates the three position cooling valve as determined by the cooling set point and proportional band settings. Description of operation Three position control has no feedback from the valve actuator to determine it’s position, so the timing of the actuator must be known to the controller. During commissioning the actuator timing must be entered.
PAGE 3
The main display shows , a) Whether Q1 is On or Off ( = off, = on ) b) Whether Q2 is On or Off ( = off, = on ) c) Whether day or night set point is selected. (¤ = day, d) X1 value ( room temperature) in ° C. = night) Other displays are available by pressing the + button, and the various displays are listed below in sequence from the main display.