User Manual

Siemens Building Technologies Application : 74 RWD82/74 – 04.2001

HVAC Products RWD82 1

RWD82/74

RWD82 Universal Controller

Application 74

Compensation shift.

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

Outside air compensation of the supply air temperature.

Optional day / night set point adjustment .

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

CCV

RWD32/74

CCV

Room temperature sensor

Outside air 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

• Outside temperature sensor can be selected as Ni1000, Pt1000, or active sensor.(X2)

• Outside air compensation of the supply air temperature set point.

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

Supplemental features

Control

Operating modes

PAGE 1
RWD82/74 RWD82 Universal Controller Application 74 Compensation shift. 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 Outside air compensation of the supply air temperature. X1 X2 S1 Q1 Q2 CCV PC Room temperature sensor Outside air temperature sensor Time clock or switch Opening output for CCV Closing output for CCV 3 - position chilled water control valve.
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 The auxiliary temperature sensor (X2) senses the outside air temperature, and adjusts the supply air temperature setpoint as per the temperature shift program set up in the controller.
PAGE 3
Main Display 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.