Orion System OE392-10 System Manager TS - Manual (Page 29)

SMTS Technical Guide
VCM & VCM-X Controllers
29
VCM & VCM-X Temperature Setpoints
Morning Warm-up Setpoint
When the VCM-X is confi gured for VAV operation and the controller en-
ters the Occupied Mode, the VCM-X looks at the Return Air Temperature
to determine if the unit should initiate Morning Warm-up Mode. If the
Return Air Temperature is below the Morning Warm-up Setpoint and the
Max Length is greater than “0,” the VCM-X will initiate Heating. This
is considered Morning Warm-up and will run until the Return Air Tem-
perature rises above the Morning Warm-up Setpoint or until the Warm
Up Timeout expires. High limit = 90ºF; Low limit = 50ºF; Default = 72ºF.
Dewpoint Dehumidifi cation Setpoint
On MUA confi gured units that are using 100% Outdoor Air, when the
OA Dewpoint Temperature rises above the Dewpoint Dehumidifi cation
Setpoint, the unit will start operating in Dehumidifi cation Mode. High
limit = 80ºF; Low limit = 35ºF; Default = 55ºF.
Economizer Enable Setpoint
If an OA Humidity Sensor is not connected to the VCM-X and the OA
Temperature falls below this Setpoint, the Economizer can be used for
Free Cooling. If an OA Humidity Sensor is connected to the VCM-X,
then a Wetbulb Temperature will be calculated and used instead of the
OA Drybulb Temperature to determine when Free Cooling can be used.
High limit = 80ºF; Low limit = 0ºF; Default = 55ºF.
Pre-Heat/Low Ambient Setpoint Temperature
For cold climates where freezing temperatures may be experienced, a Pre-
Heater relay output, if confi gured, can be activated based on the Outdoor
Air Temperature to prevent freezing of Water Coils. If the Outdoor Air
Temperature falls below the Low OAT Ambient Protection Temperature
Setpoint and the HVAC unit is in Occupied Mode, the Pre-Heater relay
will activate. High limit = 70ºF; Low limit = 0ºF; Default = 0ºF.
Cooling SAT/Low Reset Limit
For VCM-X, if no reset is confi gured, this is the Supply Air Temperature
maintained during the Cooling Mode of operation. If reset is confi gured,
this is the lowest temperature the Supply Air can be reset to. For VCM,
this is the Target Reset Source Temperature if reset is confi gured. High
limit = 80ºF; Low limit = 40ºF; Default = 55ºF.
Cooling SAT/High Reset Limit
For VCM-X, if your system requires reset of the Supply Air Temperature
in the Cooling Mode, this is the highest temperature the Supply Air can be
reset to. For VCM, this fi eld will display Reserved. High limit = 150ºF;
Low limit = 40ºF; Default = 55ºF.
Cool Staging Window
This is the level below the Supply Air Setpoint that causes the Compres-
sors to Stage Off. High limit = 20ºF; Low limit = 1ºF; Default = 5ºF.
Cooling OAT Lockout
If the Outdoor Air Temperature is below this value, the mechanical cool-
ing is prevented from activating. High limit = 100ºF; Low limit = 0ºF;
Default = 50ºF.
Low Temperature Cutoff
If the Supply Air Temperature drops below this value, all cooling is im-
mediately cut off to protect the equipment. High limit = 250ºF; Low limit
= 0ºF; Default = 40ºF.
Heating SAT/Low Reset Limit
For VCM-X, if no reset is confi gured, this is the Supply Air Temperature
maintained during the Heating Mode of operation. If reset is confi gured,
this is the lowest temperature the Supply Air can be reset to. For VCM,
this is the Target Reset Source Temperature if reset is confi gured. High
limit = 200ºF; Low limit = 40ºF; Default = 120ºF.
Heating SAT/High Reset Limit
For VCM-X, if your system requires reset of the Supply Air Temperature
in the Heating Mode, this is the highest temperature the Supply Air can be
reset to. For VCM, this fi eld will display Reserved. High limit = 200ºF;
Low limit = 40ºF; Default = 45ºF; Default = 120ºF.
Heat Staging Window
This is the level above the Supply Air Setpoint that causes the Heating to
Stage Off. High limit = 20ºF; Low limit = 1ºF; Default = 5ºF.
Heating OAT Lockout
If the Outdoor Air Temperature is above this value, the mechanical heat-
ing is prevented from activating. High limit = 150ºF; Low limit = 50ºF;
Default = 70ºF.
High Temperature Cutoff
If the Supply Air Temperature rises above this value, all heating is im-
mediately cut off to protect the equipment. High limit = 250ºF; Low limit
= 0ºF; Default = 170ºF.
Reset Interval Rate
This is the rate at which a new Supply Setpoint is calculated if a Reset
Source has been selected. This value determines how fast the Supply Air
Temperature Setpoint is adjusted as the Reset Source changes. High limit
= 250 seconds; Low limit = 1 second; Default = 20 seconds.
Reserved (VCM-X, VCM-X Modular, VCM-X WSHP) or
Low OAT Reset Limit (VCM)
The Supply Setpoint proportionally resets to its maximum setting as the
Outdoor Air Temperature drops to this low reset temperature. For VCM-
X, this fi eld will display Reserved. High limit = 100ºF; Low limit = 0ºF
Reserved (VCM-X, VCM-X Modular, VCM-X WSHP)
or High OAT Reset Limit (VCM)
The Supply Setpoint proportionally resets to its minimum setting as the
Outdoor Air Temperature rises to this high reset temperature. For VCM-
X, this fi eld will display Reserved. High limit = 100ºF; Low limit = 0ºF
Heat Wheel Defrost
The Heat Wheel Defrost Mode occurs when the Outdoor Air Temperature
is below this setpoint. High limit = 50ºF; Low limit = 0ºF; Default = 30ºF.