Viconics VBZS Application Guide - Manual (Page 16)

16
Please note:
- 0 to 100 % is directly converted to 0 to 10 VDC on the VAV damper output. If the actuator has a
positioning input range of 2 to 10 VDC, then entering 50% minimum position is not directly
converted to 50% VAV damper position. Please refer to table below
VAV damper
position required
0% 10% 20% 30% 40% 50% 60% 70% 80% 100%
Setting for 0-10
VDC Actuator
0% 10% 20% 30% 40% 50% 60% 70% 80% 100%
Setting for 2-10
VDC Actuator 0 to
20%
28% 36% 44% 52% 60% 68% 76% 84% 100%
- The damper position is never linear or proportional to airflow in a pressure dependent application.
Depending on how the zone damper was sized, a box may best slightly oversized, or slightly
undersized. In all cases, the PI loop (Proportional Integral) of the zone controller will always
compensate to find the proper required position to satisfy the current zone demand.
% opening
Air flow
% opening
Air flow
Oversized VAV
Undersized VAV
Effective
Control
Area
Effective
Control
Area
-
Be sure the VAV actuator is properly installed and set-up so the VAV damper blade is able to
rotate from the fully opened, to fully closed position with no restriction to its mechanical rotation.
2F) Terminal Reheat Lockout
It is possible to lockout out the local terminal reheat function of the zones during hot seasons or when no
longer required. This prevents users from using the local reheat function simply based on a configured
outside air temperature value.
If RehtConf is set to
AO2 OALK BO5 OALK
0 = None N/A, reheat not used N/A, reheat not used
1 = Analog Duct Reheat Only Set to desired value N/A BO5 not used by this reheat
sequence
2 = On/Off Duct Reheat Only N/A AO2 not used by this reheat
sequence Set to desired value
3 = On/Off Perimeter Reheat Only N/A AO2 not used by this reheat
sequence
Set to desired value
4 = Analog Duct Reheat & On/Off
Perimeter Reheat Set to desired value. Can be
different than BO5 OALK Set to desired value. Can be
different than AO2 OALK