Orion System System Manager TS II In-House - Manual (Page 32)

VCM & VCM-X Controllers
SMTS II Technical Guide 32
Temperature Setpoints
Touch the < Temperatures> button to access the
Temperature Setpoint Screens.
Cooling Mode Enable
This setpoint is used to determine the Cooling Mode of operation in
reference to the HVAC Mode Enable Sensor. If the Supply Air Sensor is
confi gured to be the HVAC Mode Enable, this Setpoint is used in conjunc-
tion with the Unoccupied Setbacks if equipped with a Space Temperature
Sensor. Above this temperature plus the deadband, the unit will switch
to Cooling Mode. High limit = 99ºF; Low limit = 1ºF; Default = 75ºF.
Heating Mode Enable
This setpoint is used to determine the Heating Mode of operation in
reference to the HVAC Mode Enable Sensor. If the Supply Air Sensor is
confi gured to be the HVAC Mode Enable, this Setpoint is used in conjunc-
tion with the Unoccupied Setbacks if equipped with a Space Temperature
Sensor. Below this temperature minus the deadband, the unit will switch
to Heating Mode. High limit = 90ºF; Low limit = 1ºF; Default = 70ºF.
Night Cooling Offset
During the Unoccupied Mode of Operation, this setpoint adjusts the
Cooling Mode Enable Setpoint up by this amount. If you do not want
Cooling to operate during the Unoccupied Mode, use the default setting
of 30°F for this setpoint. High limit = 30ºF (no offset); Low limit = 0ºF;
Default = 30ºF.
Night Heating Offset
During the Unoccupied Mode of Operation, this setpoint adjusts the
Heating Mode Enable Setpoint down by this amount. If you do not want
Heating to operate during the Unoccupied Mode, use the default setting
of 30°F for this setpoint. High limit = 30ºF (no offset); Low limit = 0ºF;
Default = 30ºF.
Occupied Deadband
The deadband is added to the Cooling Setpoint to generate a cooling
demand and is subtracted from the Heating Setpoint to create a heating
demand. High limit = 10ºF; Low limit = 0ºF; Default = 1ºF.
Temps
VCM & VCM-X Temperature Setpoints
Figure 49: VCM-X Temperature Setpoints Screen 1
Figure 50: VCM-X Temperature Setpoints Screen 2
Coil Setpoint
During the Dehumidifi cation Mode, the VCM-X uses the calculated Coil
Temperature to activate DX Cooling based on this Dehumidifi cation Coil
Temperature Setpoint. The VCM-X uses a Suction Pressure Transducer to
read Suction Pressure (the Saturation Vapor Pressure of the refrigerant)
and converts this Suction Pressure reading to a Coil Temperature value.
This calculation is based on using R22 or R410A refrigerant only and
will not work with any other refrigerant. This setpoint determines the
number of compressor stages that need to be activated to maintain the
Dehumidifi cation Coil Temperature Setpoint. The Coil Temperature is
maintained at this setpoint during Dehumidifi cation. High limit = 70ºF;
Low limit = 35ºF; Default = 45ºF.
Morning Warm-up Setpoint
When the VCM-X is confi gured for VAV operation and the controller
enters the Occupied Mode, the VCM-X looks at the Return Air Tempera-
ture 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
Temperature 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.