Orion System VCM - Manual (Page 26)

Technical Guide
Operator Interfaces 26
Setpoint Screen #10
VCM Spts ID 59
Morning Warm Up
Target Temp: 70
° F
Max Length..: 60 Min
When the VCM is configured for VAV operation and the controller en-
ters the Occupied Mode, the VCM 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 Target Tem-
perature and the Max Length is greater than “0”, the VCM controller
will initiate Heating. This is considered Morning Warm-up and will
run until the Return Air Temperature rises above the Morning Warm-up
Target Temperature or the Max Length Setpoint time expires.
Description Minimum Default Maximum
Morning Warm Up
Target Temp
50
°
F 72
°
F 90
°
F
Morning Warm Up
Max Length
0 Min 60 Min 240 Min
Setpoint Screen #11
VCM Spts ID 59
Dehumidification Spt
Indoor RH..: 55%
OA Dewpoint: 55
° F
On VAV or CAV configured units that are not using 100% Outdoor Air,
when the Indoor Relative Humidity percentage rises above the Indoor
RH Setpoint the unit will start operating in Dehumidification Mode.
On MUA configured units that are using 100% Outdoor Air, when the
Outdoor Air Dewpoint Temperature rises above the OA Dewpoint
Setpoint the unit will start operating in Dehumidification Mode.
Description Minimum Default Maximum
Dehumidification Spt
Indoor RH
1
%
50
%
100
%
Dehumidification Spt
OA Dewpoint
35
°
F 55
°
F 80
°
F
Programming The VCM Controller
Setpoint Screen #12
VCM Spts ID 59
Dehumidification
Coil Temperature
Setpoint: 45 ° F
During the Dehumidification Mode, the VCM uses the calculated Coil
Temperature to activate DX Cooling based on this Dehumidifcation
Coil Temperature Setpoint. The VCM uses a Suction Pressure Trans-
ducer to read Suction Pressure (the Saturation Vapor Pressure of the
Refrigerant) and converts this Suction Pressure reading to a Coil Tem-
perature value. This calculation is based on using R22 refrigerant only
and will not work with any other refrigerant. This setpoint determines
Description Minimum Default Maximum
Dehumidification Coil
Temperature Setpoint
35
°
F 45
°
F 70
°
F
Setpoint Screen #13
VCM Spts ID 59
Economizer Setpoints
OAT/WB Enable: 50 ° F
If an Outdoor Air Humidity Sensor is not connected to the VCM 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 VCM, 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
0
°
F 55
°
F 80
°
F