Orion System VCM-X/RNE Controller - Manual (Page 46)

VCM-X / RNE SETPOINTS
VCM-X / RNE Operator Interface SD 46
Setpoint Screen #5 - Cool Reset Source
VCM-X / RNE Spts
Cool Rst Source Spts
SpcHi: 75 SAT: 55º
SpcLo: 75 RST: 55º
If no Reset Source has been confi gured in Confi guration Screen #4,
then this screen will read Cool Rst Not Confi g and will not be used. If
a Reset Source has been confi gured in Confi guration Screen #4, then
the names of the values on the left side of this screen will correspond to
the Reset Source that was confi gured. This screen will then allow you
to input the upper and lower limits for the range of values of the Reset
Source on the left side of the screen and will show the corresponding
Cooling Supply Air SAT and Rst Limit values that were entered on the
previous screen. Single Zone VAV Reset of the Supply Fan VFD is ad-
dressed in the last paragraph.
Please note that the SAT and Rst Limit values on the right side of this
screen cannot be changed on this screen; they are simply displayed from
what was entered on the Setpoint Screen #4. For each line, the value on
the left corresponds to the value on the right. So, if the Space Temperature
Sensor has been confi gured as the Reset Source, then when the Space
Temperature is at or above the SpcHi Temperature Setpoint, the Supply
Air Cooling Setpoint will be reset to its lowest value, the SAT Setpoint.
If the Space Temperature is at or below the SpcLo Setpoint, the Supply
Air Cooling Setpoint will be reset to its highest value, the Cooling Rst
Limit. Then, as the Space Temperature moves from its low value to its
high value, the Supply Air Cooling Setpoint will be proportionally reset
from its high value to its low value.
Depending on whether reset has been confi gured or not, the options for
the names of the values on the left side of the screen are SpcHi, SpcLo,
OatHi, OatLo, RatHi, RatLo, VLT, VFD, NoRST.
In the examples that follow, the desired Space Temperature in
Cooling Mode is 75ºF:
Space Temperature Cool Reset:
Space Temperature (SPC Hi) = 75ºF SAT Setpoint (SAT) = 55ºF
Space Temperature (SPC Lo) = 74ºF SAT Setpoint (Rst) = 65ºF
VFD Percentage Cool Reset:
VFD Percentage (VFD) = 70% SAT Setpoint (SAT) = 55ºF
VFD Percentage (VFD) = 30% SAT Setpoint (Rst) = 65ºF
Input Voltage Cool Reset:
Input Voltage (VLT) = 0 Volts SAT Setpoint (SAT) = 55ºF
Input Voltage (VLT) = 10 Volts SAT Setpoint (Rst) = 65ºF
In the Cooling Mode in a Single Zone VAV application, the Supply Fan
VFD speed will proportionally modulate as the Space Temperature rises
within the range set on this screen. Upon entering the Cooling Mode, the
fan will start at 30% and modulate up to 100% as the Space Temperature
rises from the SpcLo Setpoint to the SpcHi Setpoint. The SpcLo Set-
point should be the same as the Space Cooling Setpoint (Mode Enable
Setpoint) from Setpoint Screen #1. The SAT and RST Setpoints on the
right side of the screen are not used.
Setpoint Screen #3 - Unoccupied Setbacks
VCM-X / RNE Spts
Unoccupied Setbacks
Cooling.........: 30ºF
Heating.........: 30ºF
During the Unoccupied Mode of Operation, these Setpoints spread the
HVAC Mode Setpoints out by a user-adjustable amount. Use only posi-
tive numbers for these Setpoints. If you do not want Cooling or Heating
to operate during the Unoccupied Mode, use the default setting of 30°F
for these setpoints.
Description Minimum Default Maximum
Unoccupied Setbacks Cooling 0ºF 30ºF 30ºF
Unoccupied Setbacks Heating 0ºF 30ºF 30ºF
Setpoint Screen #4 - SAT Cooling Setpoints
VCM-X / RNE Spts
SAT Cooling Spts
Cooling..: 55ºF
Rst Limit: 55ºF
If no Reset Source has been confi gured in Confi guration Screen #4, then
this setpoint will be the Supply Air Temperature Cooling Setpoint. Line
4 will be blank. If a Reset Source has been confi gured in Confi guration
Screen #4, then Line 4 will read Rst Limit. Reset is always upward from
the SAT setpoint to the Reset Limit setpoint. So, the SAT will be the
lowest temperature the Supply Air Setpoint can be reset to and Reset
Limit will be the highest temperature the Supply Air Setpoint can be
reset to. The Cooling Supply Air Temperature Setpoint will automati-
cally be reset warmer or colder within this range as the Reset Source
(next screen) moves within its range.
Description Minimum Default Maximum
SAT Cooling Setpoint 40ºF 55ºF 80ºF
Cooling Reset Limit 40ºF 55ºF 150ºF
VCM-X / RNE Setpoint Screens