Primary States (Box Flow Test) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 15.0

Controller Tool Help

Johnson Controls
Product name
Controller Configuration Tool
Document type
User Guide
Document number
Revision date

The module begins a test when the Begin Test command is received.

Once a test is started, it runs through to completion unless the test cancelled by the user or the module is disabled.

At the start of the test, all errors are reset to False (see below for exceptions). Once the test is complete, the data collected during the test is analyzed to flag any errors. In addition, the Percent dP Offset and Flow reliability during the test is noted.

The Max Flow and Min Flow are calculated based on the data gathered during the test (ignoring any unreliable flows of -999.999). The value of the Rated Box Flow input and Flow Tolerance property when the module finishes the test are used for the error analysis. The module otherwise ignores any changes to these values during the test.

The following are the eight possible results of the Box Flow Test module.

  • Large dP Offset: Set if the absolute value of the Percent dP Offset is greater than or equal to the dP Offset Tolerance. This indicates that an auto calibration was performed when the damper was not fully closed. This is often a symptom of a stuck or reversed actuator. This error is evaluated on input change while the test state is Test in Progress or No Test Data. The error is reset when a test begins and the absolute value of the current Percent dP Offset input is less than the dP Offset Tolerance.

  • Flow Not Reliable: Set if the Flow input Reliability is not reliable. This error is evaluated on input change while the test state is Test in Progress or No Test Data. The error is reset when a test begins and the Flow is currently reliable. This error indicates one or more of the Flow readings is not reliable.

  • Damper Command Not Responding: Set if the Damper Percent Cmd input did not reach the Step Position (within 1%) for one or more of the test steps. This indicates the application is being controlled by higher precedence logic.

  • Poor Flow Response: Set if (Max Flow - Min Flow) <= (Rated Box Flow * Flow Tolerance / 100). The Min Flow and Max Flow refer to the minimum and maximum of the recorded flow values.

  • Insufficient Flow: Set if (Max Flow) < Rated Box Flow * (100 - Flow Tolerance) / 100.

  • Excessive Flow: Set if (Max Flow) > 1.5 * Rated Box Flow.

  • Non-Increasing Flow: Check all steps (other than the starting position) against previous step to verify flow is moving in direction expected. Considered an error if moving opposite expected direction (by more than half the tolerance) for any of the steps or if the flows at the fully open or closed positions are not within the tolerance of the max or min flows, respectively.

  • Excessive Hysteresis: Evaluated only if Check Hysteresis is True. For all positions that have a pair of flow values (all steps except the end stop opposite the starting position), set error if flows differ by more than the tolerance.