Set the desired over pressure/temperature in percentage of set
point for the pressure (Pset)/temperature before entering the
Sleep Mode.
If setting for 5%, the boost pressure will be Pset*1.05. The
negative values can be used for e.g. cooling tower control where
a negative change is needed.
22-46 Maximum Boost Time
Range:
Function:
60 sec.
*
[0-600 sec.]
Only to be used if par. 1-00,
Configuration Mode
, is set for
Closed Loop and the integrated PI controller is used for con-
trolling the pressure.
Set the maximum time for which boost mode will be allowed. If
the set time is exceeded, Sleep Mode will be entered, not wait-
ing for the set boost pressure to be reached.
2.19.4. 22-5* End of Curve
The End of Curve conditions occur when a pump is yielding a too large volume to ensure the set
pressure. This can occur if there is a leakage in the distribution pipe system after the pump causing
the operating point down to the end of the pump characteristic valid for the max speed set in par.
4-13 or 4-14,
Motor Speed High Limit
. In case the feed back is lower than 97.5% of the set point
for the desired pressure for a set time (par. 22-51,
End of Curve Delay
), and the pump is running
with max speed set in par. 4-13 or 4-14,
Motor Speed High Limit
, the function selected in par.
22-50,
End of Curve Function
, will take place. If the Cascade Controller is used, all pumps must
be running to activate the End of Curve function. It is possible to get a signal on one of the digital
outputs by selecting End of Curve [192] in par. 5-3*,
Digital Outputs
and/or par. 5-4*, Relays.
The signal will be present when an End of Curve condition occurs and selection in par. 22-50,
End
of Curve Function
, is different from Off. The end of curve function can only be used when operating
with the built-in PID controller (Closed loop in par. 1.00,
Configuration Mode
).
22-50 End of Curve Function
Option:
Function:
[0]
*
Off
[1]
Warning
[2]
Alarm
Off
[0]: End of Curve monitoring not active
Warning
[1]: A warning is issued in the display [W94].
Alarm
[2]: An alarm is issued and the frequency converter trips.
A message [A94] appears in the display.
Important
: If using the cascade controller, the fixed speed
pumps are not affected by the End of Curve function and will
keep running.
22-51 End of Curve Delay
Range:
Function:
10 s
*
[0 - 600 s]
When an End of Curve condition is detected, a timer is activated.
When the time set in this parameter expires, and the End of
Curve condition has been steady in the entire period, the func-
tion set in par. 22-50,
End of Curve Function
, will be activated.
If the condition disappears before the timer expires, the timer
will be reset.
VLT
®
AQUA Drive Programming Guide
2. Parameter Description
MG.20.O2.02 - VLT
®
is a registered Danfoss trademark
205
2