Danfoss VLT AQUA Drive FC 200 Programming Manual page 177

Parameter Description
25-26 Destage At No-Flow
Option: Function:
The de-stage at the no-flow parameter ensures that
when a no-flow situation occurs, the fixed speed
pumps will be de-staged one-by-one until the no-
flow signal disappears. This requires that no-flow
detection is active. See parameter group 22-2*.
If De-stage 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 [0] Disabled,
25-28 Stage Function Time will not be activated.
[0] Disabled
[1] Enabled
25-28 Stage Function Time
Range: Function:
15 s [0 - The Stage Function Time is programmed to avoid
*
300 s] frequent staging of the fixed-speed pumps. The
Stage Function Time starts if it is [1] Enabled by
25-27 Stage Function, and when the variable-
speed pump is running at Motor Speed High Limit,
4-13 Motor Speed High Limit [RPM] or 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.
25-29 Destage Function
Option: Function:
The Destage Function ensures that the lowest
numbers of pumps are running to save energy and
to avoid dead head water circulation in the
variable-speed pump. If the Destage Function is set
to [0] Disabled, the 25-30 Destage Function Time will
not be activated.
[0] Disabled
[1] Enabled
25-30 Destage Function Time
Range: Function:
15 [0 - The Destage Function Timer is programmable to
s 300 s] avoid frequent staging/destaging of the fixed-
*
speed pumps. The Destage Function Time starts
when the adjustable speed pump is running at
4-11 Motor Speed Low Limit [RPM] or 4-12 Motor
Speed Low Limit [Hz], with one or more fixed-
®
VLT AQUA Drive Programming Guide
F VLT pump
3.22.3 25-4* Staging Settings
Parameters determining conditions for staging/de-staging
the pumps.
10 s
2 s
®
MG20O622 - VLT is a registered Danfoss trademark
25-30 Destage Function Time
Range: Function:
speed pumps in operation and system
requirements satisfied. In this situation, the
adjustable speed pump contributes a little to the
system. When the programmed value of the timer
expires, a stage is removed, avoiding dead head
water circulation in the adjustable speed pump.
Pump
switch-off
F
min
(4-12)
Figure 3.73
25-40 Ramp-down Delay
Range: Function:
[0 - When adding a fixed-speed pump controlled by
*
120 s] a soft starter, it is possible to delay the ramp-
down of the lead pump until a preset time after
the start of the fixed-speed pump to eliminate
pressure surges or water hammer in the system.
Only to be used if [1] Soft Starter is selected in
25-02 Motor Start.
25-41 Ramp-up Delay
Range: Function:
[0 - 12 When removing a fixed-speed pump controlled
*
s] by a soft starter, it is possible to delay the ramp
up of the lead pump until a preset time after
stopping the fixed-speed pump to eliminate
pressure surges or water hammer in the system.
Only to be used if [1] Soft Starter is selected in
25-02 Motor Start.
De-stage
timer period
(27-27)
3-151
3 3