22-45 Setpoint Boost
Range: Function:
0 %* [-100 - 100 %] Only to be used if par. 1-00
Configuration Mode
, is set for Closed Loop and the integrated PI con-
troller is used. In systems with e.g. constant pressure control, it is advantageous to increase the
system pressure before the motor is stopped. This will extend the time in which the motor is stopped
and help to avoid frequent start/stop.
Set the desired over pressure/temperature in percentage of set point for the pressure (Pset)/tem-
perature 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 s* [0 - 600 s] Only to be used if par. 1-00
Configuration Mode
is set for C l o sed Loop a n d the inte g r ated PI c o n trolle r
is used for controlling 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 waiting for the set boost pressure to be reached.
3.20.4 22-5* AP-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 pump to operate at the end of the pump characteristic, valid for the max. speed set in
par. 4-13
Motor Speed High Limit [RPM]
or par. 4-14
Motor Speed High Limit [Hz]
.
In case the feed back is 2.5% of the programmed value in par. 20-14
Maximum Reference/Feedb.
(or numerical value of par. 20-13
Minimum Reference/
Feedb.
whichever is highest) below 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
Motor Speed High Limit [RPM]
or par. 4-14
Motor Speed High Limit [Hz]
, - the function selected in par. 22-50
End of Curve
Function
will take place.
It is possible to get a signal on one of the digital outputs by selecting End of Curve [192] in parameter group 5-3*
Digital Outputs
and/or parameter
group 5-4*
Relays
. The signal will be present, when an End of Curve condition occurs and the 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 End of Curve monitoring not active.
[1] Warning The drive will continue to run, but activate a End of Curve warning [W94]. A drive digital output or
a serial communication bus can communicate a warning to other equipment.
[2] Alarm The drive will stop running and activate a End of Curve alarm [A 94]. A drive digital output or a
serial communication bus can communicate an alarm to other equipment.
[3] Man. Reset Alarm The drive will stop running and activate a End of Curve alarm [A 94]. A drive digital output or a
serial communication bus can communicate an alarm to other equipment.
NB!
Automatic restart will reset the alarm and start the system again.
NB!
Do not set par. 14-20
Reset Mode
, to [13] Infinite auto reset, when par. 22-50
End of Curve Function
is set to [2] Alarm. Doing so will
cause the drive to continuously cycle between running and stopping when a End of Curve condition is detected.
3 Parameter Description VLT
®
HVAC Drive Programming Guide
210
MG.11.C9.02 - VLT
®
is a registered Danfoss trademark
3
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