Danfoss VLT FC 100 Series Programming Manual page 165

Parameter Description
22-44 Wake-up Ref./FB Difference
Range:
10 % [0 - 100
*
3 3
%]
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 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].
3-138
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 setpoint for the pressure (Pset) before
canceling 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. For example, in systems with constant
pressure control, it is advantageous to increase
the system pressure before the motor is stopped.
This will extend the time during which the motor
is stopped and help to avoid frequent start/stop.
Set the desired overpressure/temperature as a
percentage of the setpoint for the pressure (Pset)/
temperature before entering sleep mode.
If set at 5%, the boost pressure will be Pset*1.05.
The negative values can be used, for example, for
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 and will not wait for
the set boost pressure to be reached.
MG11CD22 - VLT
®
VLT HVAC Drive Programming Guide
If the feedback 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 the setpoint 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).
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 adjustable frequency drive to contin-
uously cycle between running and stopping when a End of
Curve condition is detected.
® is a registered Danfoss trademark
Function:
End of Curve monitoring not active.
The adjustable frequency drive will continue to
run, but activate a End of Curve warning
[W94]. An adjustable frequency drive digital
output or a serial communication bus can
communicate a warning to other equipment.
The adjustable frequency drive will stop
running and activate a End of Curve alarm [A
94]. An adjustable frequency drive digital
output or a serial communication bus can
communicate an alarm to other equipment.
The adjustable frequency drive will stop
running and activate a End of Curve alarm [A
94]. An adjustable frequency drive digital
output or a serial communication bus can
communicate an alarm to other equipment.