Danfoss VLT AQUA FC 200 Series Programming Manual page 168

2 Parameter Description
2.17.6 20-8* PID Basic Settings
This parameter group is used to configure the basic operation of the frequency converter's PID Controller, including how it responds to a feedback that
is above or below the setpoint, the speed at which it first starts functioning, and when it will indicate that the system has reached the setpoint.
20-81 PID Normal/Inverse Control
2
Option:
[0] * Normal
[1] Inverse
20-82 PID Start Speed [RPM]
Range:
0 RPM* [0 - par. 4-13 RPM]
20-83 PID Start Speed [Hz]
Range:
0 Hz* [0.0 - par. 4-14 Hz]
20-84 On Reference Bandwidth
Range:
5 %* [0 - 200 %]
2.17.7 PID Controller, 20-9*
This group provides the ability to manually adjust this PID Controller. By adjusting the PID Controller parameters the control performance may be
improved. See section on
Controller parameters.
168
Function:
Normal
[0] causes the frequency converter's output frequency to decrease when the feedback is
greater than the setpoint reference. This is common for pressure-controlled supply fan and pump
applications.
Inverse [1] causes the frequency converter's output frequency to increase when the feedback is
greater than the setpoint reference.
Function:
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 here is reached,
the frequency converter will automatically switch to Closed Loop Mode and the PID Controller will
begin to function. This is useful in applications in which the driven load must first quickly accelerate
to a minimum speed when it is started.
Function:
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 here is
reached, the frequency converter will automatically switch to Closed Loop Mode and the PID Con-
troller will begin to function. This is useful in applications in which the driven load must first quickly
accelerate to a minimum speed when it is started.
Function:
When the difference between the feedback and the setpoint reference is less than the value of this
parameter, the frequency converter's display will show "Run on Reference". This status can be
communicated externally by programming the function of a digital output for
Warning [8]. In addition, for serial communications, the On Reference status bit of the frequency
converter's Status Word will be high (1).
On Reference Bandwidth
The
PID Introduction to VLT AQUA Drive
in the chapter
MG.20.O4.02 - VLT
VLT
NB!
This parameter will only be visible if par.0-02
NB!
This parameter will only be visible if par.0-02
is calculated as a percentage of the setpoint reference.
in the VLT AQUA Drive Design Guide
®
is a registered Danfoss trademark
®
AQUA Drive Programming Guide
Motor Speed Unit
is set to [0], RPM.
Motor Speed Unit
is set to [1], Hz.
Run on Reference/No
for guidelines on adjusting the PID