Orion System VAV II Controller v.1 - Manual (Page 33)

VAV/CAV/MUA Operator Interface SD
VAV/CAV CONTROLLER SETPOINTS
33
If the Outdoor Air Temperature drops below the Cooling Lockout set-
point by 1°F, the DX cooling will be locked out until the Outdoor Air
Temperature rises 1°F back above the Lockout Setpoint. The same 1°F
deadband applies to the Heat Lockout Setpoint except the Outdoor Air
locks out the Heating when it is above the lockout instead of below the
lockout.
Description Minimum Default Maximum
OA Lockouts Cooling -30ºF 50ºF 80ºF
OA Lockouts Heating 50ºF 75ºF 90ºF
Setpoint Screen #9 - Low Cutoff Temperature
VAV/CAV Spts ID 0001
All Cooling Cuts Off
If Supply Air Temp
Drops Below: 40ºF
If the Supply Fan VFD drops below this value, the Heat will stage off.
The Supply Fan VFD will not be allowed to drop below this value
while the unit is in Heating Mode unless the static pressure rises 0.5”
above the static setpoint See the VAV/CAV Controller Technical Guide
for detailed information on the Low Supply Air Temperature Cutoff
sequence of operation.
Description Minimum Default Maximum
Lo SAT Cutoff 30ºF 40ºF 60ºF
Setpoint Screen #10 - High Cutoff
Temperature
VAV/CAV Spts ID 0001
All Heating Cuts Off
If Supply Air Temp
Exceeds: 170ºF
If the Supply Air Temperature ever exceeds this value, all Heating
stages are immediately cutoff, regardless of run time. See the VAV/CAV
Controller Technical Guide for detailed information on the High Supply
Air Temperature Cutoff sequence of operation.
Description Minimum Default Maximum
Hi SAT Cutoff 60ºF 170ºF 250ºF
VAV/CAV Setpoint Screens
Setpoint Screen #11 - Supply Fan VFD
Percentage
VAV/CAV Spts ID 0001
Heating Stages Off
If Supply Fan VFD Is
Below: 30%
If the Supply Fan VFD drops below this value, the Heat will stage off.
The Supply Fan VFD will not be allowed to drop below this value while
the unit is in Heating Mode unless the Static Pressure rises 0.5” above
the Static Setpoint.
Description Minimum Default Maximum
Below Setpoint 0% 30% 100%
Setpoint Screen #12 - Low Ambient Protection
VAV/CAV Spts ID 0001
Pre-Heat Output ON
Continuous Below
OAT Level: 0ºF
If your air handler has at least one Heating stage and you require a Low
Ambient Protection or Preheating of the air stream, you can enter a Sup-
ply Air Temperature value that causes one stage of Heating to come on
and remain on continuous if the Outdoor Air Temperature drops below
this level. If you don’t want this protection, do not confi gure any relays
for this function.
Description Minimum Default Maximum
Low Ambient Level -50ºF 0ºF 70ºF
Setpoint Screen #13 - Economizer OAT/WB
Enable
VAV/CAV Spts ID 0001
Economizer Setpoints
OAT/WB Enable: 55ºF
If an Outdoor Air Humidity Sensor is not connected to the Unit Con-
troller and the Outdoor Air Temperature falls below this Setpoint, the
Economizer can be used for Free Cooling. If an Outdoor Air Humidity
Sensor is connected to the controller, then a Wetbulb Temperature will
be calculated and used instead of the Outdoor Air Drybulb Temperature
to determine when Free Cooling can be used.
Description Minimum Default Maximum
Economizer Setpoints
OAT/WB Enable
-30ºF 55ºF 80ºF