Danfoss VLT CDS 803 Programming Guide

20-83 PI Start Speed [Hz]
Enter the motor speed to be attained as a start signal for
commencement of PI control. Upon power up, the drive operates
using speed open loop control. When the Process PI start speed
is reached, the drive will change to PI control.
Range: Function:
0 Hz* [ 0 - 200.0
Hz]
20-84 On Reference Bandwidth
Enter the on reference bandwidth. When the PI control error (the
dierence between the reference and the feedback) is greater
than the value of this parameter, then the on reference status bit
is set high.
Range: Function:
5 %* [0 - 200 %]
3.13.4 20-9* PI Controller
20-91 PI Anti Windup
Select the regulation of an error.
Option: Function:
[0] O Continue regulation of an error
even when the output frequency
cannot be increased or decreased.
[1] * On Cease regulation of an error when
the output frequency can no longer
be adjusted.
20-93 PI Proportional Gain
Enter the process controller proportional gain. Quick control is
obtained at high amplication. However if amplication is too
great, the process may become unstable.
Range: Function:
0.50* [0 - 10 ]
20-94 PI Integral Time
Enter the process controller integral time. Obtain quick control
through a short integral time, though if the integral time is too
short, the process becomes unstable. An excessively long integral
time disables the integral action.
Range: Function:
20 s* [0.10 - 9999
s]
20-97 PI Feed Forward Factor
Enter the PI feed forward factor. The FF factor sends a constant
fraction of the reference signal to bypass PI control, so the PI
only has an eect on the remaining fraction of the control signal.
Increases dynamic performance.
Range: Function:
0 %* [0 - 400 %]
3.14 Main Menu - Compressor Functions -
Group 28
When controlling compressors, there is often a need for
limiting the numbers of starts. One way to limit the starts
is to ensure a minimum run-time (time between a start
and a stop) and a minimum interval between starts.
Parameter 28-02 Minimum Run Time can override any
normal stop command and parameter 28-01 Interval
between Starts can override any normal start command.
28-00 Short Cycle Protection
Option: Function:
[0] Disabled Short-cycle protection is disabled.
[1] * Enabled Short-cycle protection is enabled.
28-01 Interval between Starts
Range: Function:
300 s* [ 0 - 3600 s] Sets the time desired as minimum
time between 2 starts. Any normal
start command (start/jog/freeze) is
disregarded until the timer has
expired.
28-02 Minimum Run Time
Range: Function:
12 s* [ 10 - 3600 s] Sets the time desired as minimum
run-time after a normal start
command (start/jog/freeze). Any
normal stop command is
disregarded until the set time has
expired. The timer starts counting
following a normal start command
(start/jog/freeze).
A coast (inverse) or an external
interlock command overrides the
timer.
3.14.1 28-1* Oil Return Management
Insucient lubrication can be the result of oil depositing
itself in pipes and bends. Return oil deposits to the
crankcase by increasing velocity for short periods at
regular time intervals or by ensuring adequate oil return
when velocity is too low.
With oil return management enabled, the frequency
converter performs oil return by boosting the compressor
speed for a selectable duration. Program the duration in
parameter 28-13 Boost Duration. The boosts are performed
if the compressor speed has been less than 40 rps (80 Hz)
for too long. A text message on the LCP indicates oil
return boosts.
Parameters
VLT
®
Compressor Drive CDS 803
64 Danfoss A/S © 06/2019 All rights reserved. MG18P202
33

Danfoss VLT CDS 803 Specifications

General

Brand	Danfoss
Model	VLT CDS 803
Category	DC Drives
Language	English