Orion System VCM-X/RNE Controller - Manual (Page 50)

VCM-X / RNE SETPOINTS
VCM-X / RNE Operator Interface SD 50
Setpoint Screen #19 - Outdoor Air CFM Control
VCM-X / RNE Spts
OA CFM CONTROL
Min CFM.: 0.10 Kcfm
Max CFM.: 0.10 Kcfm
If controlling the Outdoor Air Damper to a CFM setpoint, this screen
allows you to set the design Minimum and Maximum required Outdoor
Airfl ow CFM values for the Air Handler. The OA Max CFM limits the
damper operation during CO
2
override conditions. K = 1000
Description Minimum Default Maximum
OA Minimum CFM 0.10 Kcfm .10 Kcfm 200 Kcfm
OA Maximum CFM 0.10 Kcfm .10 Kcfm 200 Kcfm
Setpoint Screen #20 - Outdoor Air CFM
Deadband
VCM-X / RNE Spts
OA CFM CONTROL
OA CFM DB...: 10CFM
The is the deadband above and below the OA CFM Control Setpoint
which helps prevent hunting.
Description Minimum Default Maximum
OA CFM Deadband 0 CFM 10 CFM 20,000 CFM
Setpoint Screen #21 - Economizer Maximum
Position if High CO
2
Level
VCM-X / RNE Spts
Maximum Economizer
Position if High CO2
Level Occurs.: 100%
This Setpoint allows you to set the Maximum Position the Economizer
will open if high CO
2
conditions occur in the space. The Maximum
Economizer Position Setpoint is used to limit the amount of Outdoor Air
that will be introduced to the HVAC unit in order to ensure the unit is
operating within its Heating and Cooling design limitations. As shown
in the table below, the Minimum setting for this Setpoint is the value
previously set for the Economizer Min Position Setpoint.
Description Minimum Default Maximum
Maximum Economizer
Position If High CO
2
Level Occurs
Economizer
Minimum
Position
100% 100%
VCM-X / RNE Setpoint Screens
Setpoint Screen #22 - CO
2
Protection Limit
VCM-X / RNE Spts
CO2 Protection Limit
Max Level.: 900 PPM
Reset Rnge: 100 PPM
When the CO
2
level rises above the CO
2
Protection Limit Max Level, the
Economizer’s Minimum Position will begin to reset open proportionally
between the CO
2
Protection Limit Max Level Setpoint and the Reset
Range Setpoint. The Reset Range value is added to the Max Level value.
If the CO
2
levels are equal to or above the Max Level plus the Reset
Range, the Economizer will be opened to its Maximum Economizer
Position if high CO
2
levels occur.
Description Minimum Default Maximum
CO
2
Protection Limit
Max Level
0 PPM 900 PPM 3000 PPM
CO
2
Protection Limit
Reset Range 0 PPM 100 PPM 1500 PPM
Setpoint Screen #23 - Static Setpoint,
Deadband & Control Rate
VCM-X / RNE Spts
Static Spt...: 0.50”
Deadband.....: 0.10”
Control Rate.: 10 s
For VAV units, a Supply Fan VFD or Bypass Damper Actuator is used to
maintain the Duct Static Pressure Setpoint. The Static Pressure Output
Signal varies to control the Static Pressure Setpoint. If the Duct Static
Pressure is above the Static Setpoint plus the Deadband, the Static Pres-
sure Output Signal will be reduced at every Control Rate interval. If the
Static Pressure is below the Static Setpoint minus the Deadband, the
Output signal will be increased at every Control Rate interval.
The Duct Static Pressure Control Output Signal is a non-confi gurable
Direct Acting Signal (0-10 VDC). This can be used to directly connect
to a Supply Fan VFD without any modifi cations.
When you are using a Bypass Damper Actuator to control the Duct
Static Pressure, you must set up the Bypass Damper Actuator or the
Bypass Damper so that it is Reverse Acting in operation. The Output
Signal increases (closes Bypass Damper) if the Duct Static Pressure is
below the Duct Static Pressure Setpoint by the Deadband amount and
the Output Signal decreases (opens Bypass Damper) if the Static Pres-
sure is above the Setpoint by the Deadband amount.
Description Minimum Default Maximum
Static Spt 0.10″ WG 0.50″ WG 3.0″ WG
Deadband 0.10″ WG 0.10″ WG 1.0″ WG
Control Rate 1 Sec 10 Sec 30 Sec