Danfoss VLT Programming Manual page 149

Hvac drive
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Parameter Description
22-42 Wake-up Speed [RPM]
Range:
Size related
*
22-43 Wake-up Speed [Hz]
3
3
Range:
Size related
*
22-44 Wake-up Ref./FB Difference
Range:
10 %
[0 - 100
*
%]
NOTE
If used in application where the integrated PI controller is set
for inverse control (e.g. cooling tower applications) in
20-71 PID Performance, the value set in 22-44 Wake-up Ref./FB
Difference will automatically be added.
22-45 Setpoint Boost
Range:
0
[-100 -
%
100 %]
*
22-46 Maximum Boost Time
Range:
60 s
[0 - 600
*
s]
3.20.4 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
148
VLT
[par. 4-11 - par. 4-13 RPM]
[par. 4-12 - par. 4-14 Hz]
Function:
Only to be used if 1-00 Configuration Mode is
set for Closed Loop and the integrated PI
controller is used for controlling the pressure.
Set the pressure drop allowed in percentage of
set point for the pressure (Pset) before
cancelling the Sleep Mode.
Function:
Only to be used if 1-00 Configuration Mode, is set for
Closed Loop and the integrated PI controller 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)/
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.
Function:
Only to be used if 1-00 Configuration Mode is set
for Closed Loop and the integrated PI controller 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.
MG.11.CB.02 - VLT
®
HVAC Drive Programming Guide
pump causing the pump to operate at the end of the pump
characteristic, valid for the max. speed set in 4-13 Motor
Function:
Speed High Limit [RPM] or 4-14 Motor Speed High Limit [Hz].
In case the feed back is 2.5% of the programmed value in
20-14 Maximum Reference/Feedb. (or numerical value of
20-13 Minimum Reference/Feedb. whichever is highest) below
Function:
the set point for the desired pressure for a set time
(22-51 End of Curve Delay), and the pump is running with
max. speed set in 4-13 Motor Speed High Limit [RPM] or
4-14 Motor Speed High Limit [Hz], - the function selected in
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 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 1-00 Configu-
ration Mode).
22-50 End of Curve Function
Option:
[0]
Off
*
[1]
Warning
[2]
Alarm
[3]
Man. Reset
Alarm
NOTE
Automatic restart will reset the alarm and start the system
again.
NOTE
Do not set 14-20 Reset Mode, to [13] Infinite auto reset, when
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.
NOTE
If the drive is equipped with a constant speed bypass with an
automatic bypass function that starts the bypass if the drive
experiences a persistent alarm condition, be sure to disable
the bypass's automatic bypass function, if [2] Alarm or [3]
Man. Reset Alarm is selected as the End of Curve Function.
®
is a registered Danfoss trademark
Function:
End of Curve monitoring not active.
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.
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.
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.

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