Attributes (Min OA Fan Variable Capacity Flow Control) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Controller Tool Help

Brand
Johnson Controls
Metasys
Product name
Controller Configuration Tool
Document type
User Guide
Document number
LIT-12011147
Version
15.0
Revision date
2022-11-18
Language
English

The following table describes the attributes used by the Min OA Fan Variable Capacity Flow Control modules:

Table 1. Min OA Fan Variable Capacity Flow Control Attributes

Name

Type 1

Description

Default Value

Damper Delay

 

Allows the damper to start opening before the fan is energized. The damper delay defines the amount of time between the damper opening and the fan starting.

30 Seconds

Damper OpenClose

 

Contains the control signal for the minimum OA damper. The enumeration set only has two values, Close and Open.

Close

Set Name: Close/Open

Fan OnOff

 

Binary signal for the minimum injection fan. The enumeration set only has two values, Off and On.

Off

Set Name: Off/On

Fan Percent Cmd

 

Analog signal for the minimum injection fan, it is used to command a fan speed. This output can range from 0% to 100%.

0%

Low Limit Delay

 

Defines the time the damper remains closed once the low limit process variable rises above the low limit setpoint minus the deadband.

180 Seconds

Low Limit Process Variable

 

Specifies the low limit temperature process variable. This temperature is usually the mixed air temperature or the preheat air temperature.

7 °C, 45 °F

Low Limit Proportional Band

 

Defines the temperature range where the damper is proportionally modulated to control the mixed air temperature to the low limit temperature setpoint.

5 °C, 9 °F

Low Limit Setpoint

 

Upper threshold for the low limit process function. When the low limit process variable is above this temperature, the minimum injection fan may be modulated to provide adequate levels of outdoor air. Below this setpoint, outdoor air levels may be limited by resetting the flow setpoint to control the low limit process variable to the low limit setpoint.

7 °C, 45 °F

Minimum OA Flow

 

Flow through the minimum OA damper.

940 l/s, 2000 cfm

Minimum OA Flow Setpoint

 

Contains the desired flow through the minimum OA damper. This module does not perform any setpoint reset. If that function is desired, it must be performed in another module.

940 l/s, 2000 cfm

MOAFLOW-RANGE (Minimum OA Flow Range)

 

Specifies that the magnitude of the range that the PID Process Variable traverses as the PID Present Value varies between its minimum and maximum values. For example, when the Process Variable ranges between 200 and 2000 l/s due to the PID Present Value varying from is Low Limit to its High Limit, then Process Range is set to 1800 (|2000 - 200|). This input is location specific.

850 l/s, 1800 cfm

MOA-OUTSTATE (State)

 

Represents the current module mode of operation.

No Flow

Set Name: AHU MinOA VFD Fan State

Mode

 

Desired mode of operation.

No Flow

Set Name: AHU MinOA VFD Fan Mode

Output Overridden

 

Indicates when the actual output controlled by this output is overridden by a user.

False

Output Position

 

Provides the current Present Value of the output that this controller drives.

0%

PID Tuning Reset

 

Causes the PID objects to reset their tuning parameters to the default based on the appropriate Process ID.

Normal

Set Name: PID Tuning Reset

Process Units

 

Specifies the units for the PID. For this particular module, l/s, cu m/h, and cfm are the only valid values.

l/s, cfm

Set Name: Unit

Unrel Flow Mode

 

Defines the module behavior when the flow station sensor is unreliable.

No Flow

Set Name: NoFlow/Flow

1 C - Configuration Mode Only, G - Default Element (Generated State, if applicable), SC - Simulation and Commissioning Modes Only, V - Calculated Value (Outputs)