Vcm-x / rne setpoints, Vcm-x / rne setpoint screens, Vcm-x / rne operator interface sd – Orion System VCM-X/RNE Controller User Manual

Page 47

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VCM-X / RNE Operator Interface SD

VCM-X / RNE SETPOINTS

47

Setpoint Screen #6 - SAT Heating Setpoints

If no Reset Source has been confi gured in Confi guration Screen #4, then
this setpoint will be the Supply Air Temperature Heating 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 Heating Supply Air Temperature Setpoint will automatically
be reset warmer or colder within this range as the Reset Source (next
screen) moves within its range.

VCM-X / RNE Spts
SAT Heating Spts

Heating..: 120ºF
Rst Limit: 120ºF

Description

Minimum

Default

Maximum

SAT Heating Spt

40ºF

120ºF

200ºF

Reset Limit Spt

40ºF

120ºF

200ºF

Setpoint Screen #7 - Heat Reset Source

VCM-X / RNE Spts

Heat Rst Source Spts

SpcHi: 70 SAT: 120º
SpcLo: 70 RST: 120º

If no Reset Source has been confi gured in Confi guration Screen #4, then
this screen will read Heat Rst Not Confi g and will not be used. If a Reset
Source has been confi gured in Confi guration Screen #6, 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 Heating
Supply Air SAT and Rst Limit values that you entered on the previous
screen. Single Zone VAV Reset of the Supply Fan VFD is addressed 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 #6. 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 Heating 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 Heating Setpoint will be reset to its highest value, the Heating Rst
Limit. Then, as the Space Temperature moves from its low value to its
high value, the Supply Air Heating Setpoint will be proportionally reset
from its high value to its low value.

VCM-X / RNE Setpoint Screens

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 Heat-
ing Mode is 71ºF:

Space Temperature Heat Reset:
Space Temperature (SPC Hi) = 71ºF SAT Setpoint (SAT) = 90ºF
Space Temperature (SPC Lo) = 70ºF SAT Setpoint (Rst) = 120ºF

VFD Percentage Heat Reset:
VFD Percentage (VFD) = 30% SAT Setpoint (SAT) = 90ºF
VFD Percentage (VFD) = 70% SAT Setpoint (Rst) = 120ºF

Input Voltage Heat Reset:
Input Voltage (VLT) = 0 Volts SAT Setpoint (SAT) = 90ºF
Input Voltage (VLT) = 10 Volts SAT Setpoint (Rst) = 120ºF

In the Heating Mode in a Single Zone VAV application, the Supply Fan
VFD speed will proportionally modulate as the Space Temperature falls
within the range set on this screen. Upon entering the Heating Mode, the
fan will start at 50% and modulate up to 100% as the Space Temperature
falls from the SpcHi Setpoint to the SpcLo Setpoint. The SpcHi Setpoint
should be the same as the Space Heating 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 #8 - Stage Control Window

VCM-X / RNE Spts

Stage Control Window

Cooling.........: 5ºF
Heating.........: 5ºF

When the Unit Controller is in Cooling Mode, if the Supply Air Tem-
perature drops below the Active Supply Air Temperature Setpoint mi-
nus the Cooling Stage Control Window value, a Cooling Stage will be
deactivated after its Minimum Run Time. In the Heating Mode, if the
Supply Air Temperature rises above the Active Supply Air Temperature
Setpoint plus the Heating Stage Control Window value, a Heating stage
will be deactivated after its Minimum Run Time. This staging window
is also used for the coil temperature during Dehumidifi cation Mode.

Description

Minimum

Default

Maximum

Stage Control Window Cooling

5ºF

5ºF

30ºF

Stage Control Window Heating

5ºF

5ºF

30ºF

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