25-25 OBW Time
Range:
Function:
10 s*
[0 - 300 s]
Staging a fixed speed pump creates a momentary pressure peak in the system, which might exceed
the Override Bandwidth (OBW). It is not desirable to destage a pump in response to a staging
pressure peak. The OBW Time can be programmed to prevent staging until the system pressure
has stabilized and normal control established. Set the timer to a value that allows the system to
stabilize after staging. The 10 second factory setting is appropriate in most applications. In highly
dynamic systems, a shorter time may be desirable.
25-26 Destage At No-Flow
Option:
Function:
The Destage at No-Flow parameter ensures that when a no-flow situation occurs, the fixed speed
pumps will be destaged one-by-one until the no-flow signal disappears. This requires that No Flow
Detection is active. See par. 22-2*.
If Destage at No-Flow is disabled the Cascade Controller does not change the normal behavior of
the system.
[0] *
Disabled
[1]
Enabled
25-27 Stage Function
Option:
Function:
If the Stage Function is set to
Disabled
[0], par. 25-28
Stage Function Time
will not be activated.
[0]
Disabled
[1] *
Enabled
25-28 Stage Function Time
Range:
Function:
15 s*
[0 - 300 s]
The Stage Function Time is programmed to avoid frequent staging of the fixed speed pumps. The
Stage Function Time starts if it is
Enabled
[1] by par. 25-27
Stage Function
, and when the variable
speed pump is running at
Motor Speed High Limit
, par. 4-13
Motor Speed High Limit [RPM]
or
par. 4-14
Motor Speed High Limit [Hz]
, with at least one fixed speed pump in the stop position.
When the programmed value of the timer expires, a fixed speed pump is staged.
2 Parameter Description
VLT
p
Automation VT Drive FC322
Programming Guide
244
MG.20.W1.22 - VLT
p
is a registered Danfoss trademark
2
Remote Site Products - 1-888-532-2706 - www.remotesiteproducts.com
http://www.remotesiteproducts.com/p-20772-Danfoss-131X8135-VLT-Automation-VT-Drive-VFD-FC322-230V-5-HP.aspx