Installation and Maintenance Manual

Unit Installation
VAV-SVX08E-EN 15
Stand Alone VV550 LonTalk™ Control
When there is no communication to the VV550 control and
the unit is in the stand alone mode the control action is
determined by the auxiliary temperature sensor located
on TB3-5 and TB3-6 terminals on the VV550 board. The
control must also be configured through the “Inputs Tab”
of Analog Input 4 as “Primary Supply Air Sensor”. In order
for the auxiliary sensor to determine the control action
(heat, cool) it must be located in the supply inlet of the
duct. The auxiliary temperature is then compared to the
zone temperature. If the supply air temperature is 10
degrees above the zone temperature, then the control
action will be heat. If the supply air temperature is less
than or equal to the zone temperature, then the control
action will be cool. If the supply air temperature is between
the zone temperature and the zone temperature + 10ºF
(5.5°C)(zone temperature < supply air temperature < zone
temperature + 10ºF) (5.5°C), the control action remains the
same and the UCM controls to the minimum flow set
point. If an auxiliary sensor is not installed the UCM will
retain the last control action in effect.
Stand Alone UC400
When there is no communication to the UC400 control and
the unit is in the stand alone mode the control action is
determined by the auxiliary temperature sensor located
on AI5 terminals on the UC400 control. This input may
have to be changed from AI4 (Discharge Air Input) as wired
from the factory. In order for the auxiliary sensor to
determine the control action (heat, cool) it must be located
in the supply inlet of the duct. The auxiliary temperature is
then compared to the zone temperature. If the supply air
temperature is 10 degrees above the zone temperature,
then the control action will be heat. If the supply air
temperature is less than or equal to the zone temperature,
then the control action will be cool. If the supply air
temperature is between the zone temperature and the
zone temperature + 10ºF (5.5°C)(zone temperature <
supply air temperature < zone temperature + 10ºF) (5.5°C),
the control action remains the same and the UCM controls
to the minimum flow set point. If an auxiliary sensor is not
installed the UCM will retain the last control action in
effect.