20-74 Maximum Feedback Level
Range:
Function:
999999.000 User Units
*
[Value of
par. 20-73 to 999999.999]
The maximum allowable feedback level should be entered here in User units as defined in par 20-12. If the level
rises above par 20-74, autotuning is aborted and an error message will appear on the LCP.
20-79 PID autotuning
Option:
Function:
This parameter starts the PID autotuning sequence. Once the autotuning has successfully completed and the
settings have been accepted or rejected by the user, by pressing [OK] or [Cancel] buttons on the LCP at the
end of tuning, this parameter is reset to [0] Disabled.
[0]
*
Disabled
[1]
Enabled
3.18.6. 20-8* 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
Option:
Function:
[0]
*
Normal
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.
[1]
Inverse
Inverse
[1] causes the frequency converter’s output frequency to increase when the feedback is greater than
the setpoint reference. This is common for temperature-controlled cooling applications, such as cooling towers.
20-82 PID Start Speed [RPM]
Range:
Function:
0
*
[0 - 6000 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 here is reached, the frequency con-
verter 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.
NB!
This parameter will only be visible if par. 0-02 is set to [0], RPM.
20-83 PID Start Speed [Hz]
Range:
Function:
0 Hz
*
[0 - par. 4-14 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 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.
NB!
This parameter will only be visible if par. 0-02 is set to [1], Hz.
3. Parameter Description
VLT
®
HVAC Drive Programming Guide
162
MG.11.C5.02 - VLT
®
is a registered Danfoss trademark
3