Danfoss VLT FC 102 Programming Manual page 555

Programming Guide | VLT® HVAC Drive FC 102
Set the staging bandwidth (SBW) percentage to accommodate normal system pressure fluctuation. In cascade control systems, to avoid
frequent switching of fixed speed pumps, the desired system pressure is typically kept within a bandwidth rather than at a constant level.
The SBW is programmed as a percentage of parameter 20-13 Minimum Reference/ Feedb. and parameter 20-14 Maximum Reference/
Feedb. For example, if the setpoint is 5 bar and the SBW is set to 10%, a system pressure between 4.5 and 5.5 bar is tolerated. No staging
or destaging occurs within this bandwidth.
SBW Setpoint
SBW
Figure 102: Staging Bandwidth
25-21 Override Bandwidth
Default value: 100%
Setup:
All setups
Data type: Uint8
When a large and quick change in the system demand occurs (such as a sudden water demand), the system pressure rapidly changes
and an immediate staging or destaging of a fixed-speed pump becomes necessary to match the requirement. The override bandwidth
(OBW) is programmed to override the staging/destaging timer (parameter 25-23 SBW Staging Delay and parameter 25-24 SBW
Destaging Delay) for immediate response. Always program the OBW to a higher value than the value set in parameter 25-20 Staging
Bandwidth. The OBW is a percentage of parameter 3-02 Minimum Reference and parameter 3-03 Maximum Reference.
© 2024.10
Parameter type:
Conversion index:
Change during operation:
AU430028034214en-001901 / 130R0310 |
Parameter Descriptions
Range, par. 25-20 - 100 %
0
True
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