Danfoss VLT AQUA Drive FC 200 Programming Manual page 150

Parameter Description
22-45 Setpoint Boost
Range: Function:
0 [-100 Only to be used if 1-00 Configuration Mode, is set
% - 100 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 (P
temperature before entering the Sleep Mode.
If setting for 5%, the boost pressure will be
P *1.05. The negative values can be used for e.g.
set
cooling tower control where a negative change is
needed.
22-46 Maximum Boost Time
Range: Function:
60 s [0 - Only to be used if 1-00 Configuration Mode is set
*
600 s] 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.
3.19.5 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 pump to operate at the
end of the pump characteristic, valid for the max. speed
set in 4-13 Motor 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
3-03 Maximum Reference below 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 Configuration Mode).
®
VLT AQUA Drive Programming Guide
22-50 End of Curve Function
Option:
[0]
[1]
[2]
)/
set
[3]
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 frequency converter to continuously cycle
between running and stopping when a End of Curve
condition is detected.
NOTE
If the frequency converter is equipped with a constant
speed bypass with an automatic bypass function that starts
the bypass if the frequency converter 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.
22-51 End of Curve Delay
Range:
10 s
3.19.6 22-6* Broken Belt Detection
The Broken Belt Detection can be used in both closed and
open loop systems for pumps and fans. If the estimated
motor torque is below the broken belt torque value
(22-61 Broken Belt Torque) and the frequency converter
®
MG20O602 - VLT is a registered Danfoss trademark
Function:
Off End of Curve monitoring not active.
*
Warning The frequency converter will continue to run,
but activate a End of Curve warning [W94]. A
frequency converter digital output or a serial
communication bus can communicate a
warning to other equipment.
Alarm The frequency converter will stop running and
activate a End of Curve alarm [A 94]. A
frequency converter digital output or a serial
communication bus can communicate an
alarm to other equipment.
Manual The frequency converter will stop running and
Reset activate a End of Curve alarm [A 94]. A
Alarm frequency converter digital output or a serial
communication bus can communicate an
alarm to other equipment.
Function:
[0 - 600 When an End of Curve condition is detected, a
*
s] 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 function set in 22-50 End of Curve Function
will be activated. If the condition disappears
before the timer expires, the timer will be reset.
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