Orion System VAV II Controller v.1 - Manual (Page 47)

VAV/CAV/MUA Operator Interface SD
MUA II CONTROLLER SETPOINTS
47
Setpoint Screen #9 - Set Supply Air
Temperature Reset
MUA II SPTS 0001
Set SAT Temp Reset
SPC = 0 Spt = 70
SPC = 0 Rst = 70
A Type III Thermistor Sensor connected to Analog Input #1 can be used
to reset the Supply Air Temperature. This screen allows you to set the
Reset Source Temperatures that the Reset will begin at and the new Reset
Supply Air Temperature range. Determine a desired Space Temperature
you would like to maintain and enter a temperature in the top SPC fi eld
that is 2 degrees higher than your desired Space Temperature. Next,
using the desired Space Temperature you would like to maintain, enter
a temperature in the bottom SPC fi eld that is 2 degrees lower than your
desired Space Temperature. Then enter a value in the “Rst” fi eld on
this screen that is equal to the highest Supply Air Temperature desired.
Whatever Supply Air Temperature you enter for “Rst”, when added
together and divided by 2, should result in a temperature value equal to
your desired Space Temperature.
The “Spt” fi eld value cannot be changed from this screen. This Supply
Air Temperature Setpoint (Spt) must be set from Setpoint Screen #1 on
page 46 and should be set to the lowest Supply Air Temperature that
is desired.
Supply Air Temperature Reset Example:
*Desired Space Temperature is 70°F
Space Temperature (SPC) = 72°F SAT Setpoint (Spt) = 55°F
Space Temperature (SPC) = 68°F SAT Setpoint (Rst) = 85°F
Description Minimum Default Maximum
Minimum Range 40ºF 0ºF 100ºF
Maximum Range 40ºF 0ºF 100ºF
Reset SAT Spt SAT Spt Spt + 50ºF
MUA II Setpoint Screens
Setpoint Screen #7 - Alarm Limits
MUA II SPTS 0001
Alarm Limits
Hi SAT Limit: 150ºF
Lo SAT Limit: 0ºF
If the Supply Air Temperature ever rises above the High SAT Limit or
drops below the Low SAT Limit for a user-defi ned period of time, an
alarm is generated.
Description Minimum Default Maximum
High SAT Limit 50ºF 150ºF 150ºF
Low SAT Limit 0ºF 0ºF 70ºF
Setpoint Screen #8 - Supply Air Alarm
MUA II SPTS 0001
Supply Air Alarms If
Out Of Range For
30 Min
This is the amount of time the Supply Air Temperature must be outside
either the High or Low SAT Limit Setpoint before it generates an alarm.
Description Minimum Default Maximum
Supply Air Alarms If
Out of Range For X
Minutes
0 Min 30 Min 300 Min