Issue
In an MP-V controller, Box flow is reading air flow when the VAV damper is closed
Product Line
EcoStruxure Building Operation
Environment
- Building Operation Multi-purpose VAV FW v2.00.01.00016
- Building Operation Workstation (Version 2.0.x or later)
Cause
Confinguring the MP-V Box Flow Zero Point WebHelp article in Building Management System WebHelp is missing steps needed for MP-V with firmware version 2.00.01.00016.
Resolution
In addition to the procedure described in Configuring the MP-V Box Flow Zero Point, two additional steps are required to zero the Box flow on an MP-V using firmware version 2.00.01.00016.
Under Flow Balance Data...
- The Box Measured maximum flow must be an appropriate value based on the box size.
- The Hood Measured maximum flow must be an appropriate value based on the box size.
Once the procedure in WebHelp is followed and these to settings are configured, the Box Flow will read zero when the Velocity Pressure is below the Minimum value setting in Velocity Pressure properties.
If the Box Flow is still a non-zero value:
- While the damper is closed, put in an offset value to counter the Box Flow
- Make sure that the minimum value setting is a small positive value ex/ 0.002
