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Viconics VBZS Application Guide User Manual

Page 27

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27

Economizer Mode and CO

2

Level Control

If the fresh air damper is to be used for both free cooling and CO

2

level control (economizer mode and CO

2

level control, but without fresh air measurement station), only the Min Pos, Max Pos, Min CO

2

and Max CO

2

parameters as well as the free cooling sequence will be active.

-

The FA Range parameter should be set to 0 CFM.

-

Set AI4 parameter to CO

2

(0 VDC = 0ppm ; 10VDC = 2000ppm)

-

Min Pos, Max Pos, Min CO

2

and Max CO

2

parameters should be set according to the required

setting.

Min Pos

Max Pos

Min CO

2

Max

CO

2

Current
Fresh Air
Damper
Position

Current
CO

2

Level

The higher value between free cooling output and interpolation output between the above graphic
will be the signal sent to the fresh air damper.