Danfoss VLT HVACDrive User Manual

20-70 Closed-loop Type
Option: Function:
This parameter defines the application response. The default mode should be sufficient for most
applications. If the application response speed is known, it can be selected here. This will decrease
the time needed for carrying out PID autotuning. The setting has no impact on the value of the
tuned parameters and is used only for the autotuning sequence.
[0] * Auto
[1] Fast Pressure
[2] Slow Pressure
[3] Fast Temperature
[4] Slow Temperature
20-71 PID Performance
Option: Function:
[0] * Normal Normal setting of this parameter will be suitable for pressure control in fan systems.
[1] Fast Fast setting would generally be used in pumping systems, where a faster control response is de-
sirable.
20-72 PID Output Change
Range: Function:
0.10 N/A* [0.01 - 0.50 N/A] This parameter sets the magnitude of step change during autotuning. The value is a percentage of
full speed. This means that if the maximum output frequency inpar. 4-13
Motor Speed High Limit
[RPM]
/par. 4-14 Motor Speed High Limit [Hz] is set to 50 Hz, 0.10 is 10% of 50 Hz, which is 5 Hz.
This parameter should be set to a value resulting in feedback changes of between 10% and 20%
for best tuning accuracy.
20-73 Minimum Feedback Level
Range: Function:
-999999.00
0 Proc-
essCtrlU-
nit*
[Application dependant] The minimum allowable feedback level should be entered here in user units as defined in
par. 20-12
Reference/Feedback Unit . If the level falls below par. 20-73 Minimum Feedback Level ,
autotuning is aborted and an error message will appear on the LCP.
20-74 Maximum Feedback Level
Range: Function:
999999.000
ProcessCtr-
lUnit*
[Application dependant] The maximum allowable feedback level should be entered here in user units as defined in
par. 20-12
Reference/Feedback Unit . If the level rises above par. 20-74 Maximum Feedback Level ,
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
7 How to Program the Adjustable Frequency
Drive
VLT
®
HVAC Drive Instruction Manual
7-40 MG.11.AB.22 - VLT
®
is a registered Danfoss trademark
7

Danfoss VLT HVACDrive Specifications

General

Brand	Danfoss
Model	VLT HVACDrive
Category	DC Drives
Language	English