The following table describes the attributes used by the Loss of Airflow Sequencing module.
|
Name |
Description |
Default Value |
|---|---|---|
|
Air Proving Switch |
Proof of airflow input. This is an enumerated input with two possible values: Off and On. |
Off Set Name: Off/On |
|
Delay |
Defines the maximum time required for the fan to prove. If the fan is commanded on and does not prove within this time, the unit enters either the manual recovery fault state or the self recovery fault state. |
30 Seconds |
|
Electric Heat |
Indicates when electric heat is used. Units with electric heat may require low flow protection. |
False |
|
Flow Debounce |
Defines the amount of time the module ignores a temporary loss of airflow before it takes action. |
10 Seconds |
|
Hardware Restart |
Provides a hardware binary input for fault recovery. |
Normal Set Name: Normal/Trigger |
|
Min Air Flow Setpoint |
Defines the minimum amount of airflow required for operating the electric heat. |
200 l/s, 424 cfm |
|
Network Restart |
Provides a network input for fault recovery. |
Normal Set Name: Normal/Trigger |
|
NOFLOW-STATE (State) |
Current state of the activity. This output is connected to the state selection matrix. |
Set Name: AHU Flow States |
|
Proof of Airflow |
Shows the current airflow status. The output may be True, False, or Fault. True means the fan was commanded on and airflow has been detected. False means the fan was not commanded on. Fault means the fan was commanded on, but airflow proof has not been detected. This output would be connected to the MSC module Proof of Airflow input for a staged device. |
Set Name: False/True/Fault |
|
Restart Config |
Configures the sequencer for manual fault recovery. When set to True, a fault requires manual intervention for recovery. When set to False, the unit may self recover. To exit the manual reset mode, the operator must use the Hardware Restart or the Network Restart inputs to clear the fault. |
False |
|
Supply Fan OnOff |
Supply fan command. The activity uses this input to determine if the fan was commanded on or off. |
Off Set Name: Off/On |
|
Supply Fan Status |
Shows the current airflow status. The output may be either True when there is proof of airflow or False when there is not. This output would be connected to the Free Cooling Availability module Supply Fan Status input. |
|
|
Supply Flow |
Contains the airflow measurement. This input may be used on a unit with electric heat to make sure the heating coils have enough airflow. |
200 l/s, 424 cfm |