Orion System VCM-X/RNE Operator Interfaces - Manual (Page 42)

VCM-X / RNE SETPOINTS
VCM-X / RNE Operator Interfaces Technical Guide 42
Setpoint Screen #13 - Dehumidifi cation Indoor
RH & OA Dewpoint
VCM-X / RNE Spts
Dehumidification Spt
Indoor RH....: 50%
OA Dewpoint..: 55ºF
On VAV or CAV confi gured 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 Dehumidifi cation Mode.
If an Indoor Humidity Sensor is installed, the unit will reset the Coil
Suction Temperature Setpoint as needed to maintain this Indoor RH
Setpoint. This includes VAV, CAV and MUA applications.
On MUA confi gured units that are using 100% Outdoor Air, when the
Outdoor Air Dewpoint Temperature rises above the OA Dewpoint Set-
point, the unit will start operating in Dehumidifi cation Mode.
Description Minimum Default Maximum
Dehumidifi cation Setpoint
Indoor RH
1% 50% 100%
Dehumidifi cation Setpoint
OA Dewpoint
35ºF 55ºF 80ºF
Setpoint Screen #14 - Dehumidifi cation Coil
Temperature
VCM-X / RNE Spts
Dehumidification
Coil Temperature
Setpoint.....: 45ºF
During the Dehumidifi cation Mode, the VCM-X / RNE uses the calcu-
lated Coil Temperature to activate DX Cooling based on this Dehumidi-
fi cation Coil Temperature Setpoint. The VCM-X / RNE 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.
Description Minimum Default Maximum
Dehumidifi cation Coil
Temperature Setpoint 35ºF 45ºF 70ºF
VCM-X / RNE Setpoint Screens
Setpoint Screen #15 - Cooling Head Pressure
Setpoint
VCM-X / RNE Spts
Cooling
Head Pressure
Setpoint: 315PSI
If you are using the Head Pressure Module, this is the Cooling Setpoint
for control of the condenser fan speed. This is based on the highest
head pressure reading of up to 4 Head Pressure Sensors. This screen
only applies if using the VCM-X Modular, VCM-X WSHP Controller,
or RNE Controller.
See the One Condenser Head Pressure Module Technical Guide, the
Two Condenser Head Pressure Module Technical Guide, or the RNE
Controller Technical Guide for detailed information.
Description Minimum Default Maximum
Cooling Head Pressure
Setpoint
200 PSI 315 PSI 400 PSI
Setpoint Screen #16 - Reheat Head Pressure
Setpoint
VCM-X / RNE Spts
Reheat
Head Pressure
Setpoint: 400PSI
If you are using the Head Pressure Module, this is the Reheat Setpoint
for control of the condenser fan speed during dehumidifi cation. This is
based on the highest head pressure reading of up to 4 Head Pressure
Sensors. This screen only applies if using the VCM-X Modular, VCM-X
WSHP Controller, or RNE Controller.
See the One Condenser Head Pressure Module Technical Guide, the
Two Condenser Head Pressure Module Technical Guide, or the RNE
Controller Technical Guide for detailed information.
Description Minimum Default Maximum
Reheat Head Pressure
Setpoint
200 PSI 400 PSI 400 PSI