Danfoss VLT FC 102 Programming Manual page 188

Parameter Descriptions
20-79 PID Autotuning
Option:
[0] Disabled
*
3 3
[1] Enabled
3.18.6 20-8* PID Basic Settings
This parameter group is used to configure the basic
operation of the PID controller, including:
•
Response to feedback above or below the
setpoint.
•
The speed at which it first starts functioning.
•
When it indicates that the system has reached
the setpoint.
20-81 PID Normal/ Inverse Control
Option:
[0] Normal
*
[1] Inverse
20-82 PID Start Speed [RPM]
Range:
Size
related RPM]
*
186
Function:
tuning, this parameter is reset to [0]
Disabled.
Enables PID auto-tuning.
Function:
The frequency converter's output
frequency decreases when the
feedback is greater than the
setpoint reference. This behaviour is
common for pressure-controlled
supply fan and pump applications.
The frequency converter's output
frequency increases when the
feedback is greater than the
setpoint reference. This behaviour is
common for temperature-controlled
cooling applications, such as
cooling towers.
Function:
NOTICE
[ 0 - par. 4-13
This parameter is only visible if
parameter 0-02 Motor Speed
Unit is set to [0] RPM.
When the frequency converter is
first started, it initially ramps up to
this output speed in open-loop
mode, following the active ramp-up
time. When the output speed
programmed is reached, the
frequency converter automatically
switches to closed-loop mode and
the PID controller begins to
function. This is useful in
applications that require quick
acceleration to a minimum speed at
start-up.
Danfoss A/S © 10/2019 All rights reserved.
®
VLT HVAC Drive FC 102
20-83 PID Start Speed [Hz]
Range:
Size
related
*
20-84 On Reference Bandwidth
Range:
5 %
*
3.18.7 20-9* PID Controller
This group provides the ability to manually adjust the PID
controller. By adjusting the PID controller parameters, the
control performance may be improved. See the VLT
Drive FC 102 Design Guide for guidelines on adjusting the
PID controller parameters.
Function:
NOTICE
[ 0 - par. 4-14
Hz]
This parameter is only visible if
parameter 0-02 Motor Speed
Unit is set to [1] Hz.
When the frequency converter is
first started, it initially ramps up to
this output frequency in open-loop
mode, following the active ramp-up
time. When the output frequency
programmed is reached, the
frequency converter automatically
switches to closed-loop mode and
the PID controller begins to
function. This is useful in
applications that require quick
acceleration to a minimum speed at
start-up.
Function:
[0 - 200 %] When the difference between the
feedback and the setpoint reference
is less than the value of this
parameter, the frequency
converter's display shows Run on
Reference. This status can be
communicated externally by
programming the function of a
digital output for [8] Run on
Reference/No Warning. Also, for
serial communications, the On
Reference status bit of the
frequency converter status word is
high (value = 1).
The On Reference Bandwidth is
calculated as a percentage of the
setpoint reference.
®
HVAC
M0010001