Danfoss VLT FC 102 Operating Instructions Manual page 116

6 How to Programme the Low Harmonic Drive
20-94 PID Integral Time
Range:
20.00 s* [0.01 - 10000.00 s]
22-21 Low Power Detection
Option:
[0] * Disabled
6
[1] Enabled
22-22 Low Speed Detection
Option:
[0] * Disabled
[1] Enabled
22-23 No-Flow Function
Common actions for Low Power Detection and Low Speed Detection (Individual selections not possible).
Option:
[0] * Off
[1] Sleep Mode
[2] Warning
[3] Alarm
NB!
Do not set par. 14-20
the drive to continuously cycle between running and stopping when a No Flow condition is detected.
NB!
If the drive is equipped with a constant speed bypass with an automatic bypass function that starts the bypass if the drive experiences
a persistent alarm condition, be sure to disable the bypass's automatic bypass function, if [3] Alarm is selected as the No-Flow Function.
22-24 No-Flow Delay
Range:
10 s* [1 - 600 s]
116
Function:
Over time, the integrator accumulates a contribution to the output from the PID controller as long
as there is a deviation between the Reference/Setpoint and feedback signals. The contribution is
proportional to the size of the deviation. This ensures that the deviation (error) approaches zero.
Quick response on any deviation is obtained when the integral time is set to a low value. Setting it
too low, however, may cause the control to become unstable.
The value set, is the time needed for the integrator to add the same contribution as the proportional
part for a certain deviation.
If the value is set to 10,000, the controller will act as a pure proportional controller with a P-band
based on the value set in par. 20-93
from the proportional controller will be 0.
Function:
If selecting Enabled, the Low Power Detection commissioning must be carried out in order to set
the parameters in group 22-3* for proper operation!
Function:
Select Enabled for detecting when the motor operates with a speed as set in par. 4-11
Low Limit [RPM] or par. 4-12 Motor Speed Low Limit [Hz] .
Function:
The drive will enter Sleep Mode and stop when a No Flow condition is detected. See parameter
group 22-4* for programming options for Sleep Mode.
The drive will continue to run, but activate a No-Flow Warning [W92]. A drive digital output or a
serial communication bus can communicate a warning to other equipment.
The drive will stop running and activate a No-Flow Alarm [A 92]. A drive digital output or a serial
communication bus can communicate an alarm to other equipment.
Reset Mode , to [13] Infinite auto reset, when par. 22-23 No-Flow Function is set to [3] Alarm. Doing so will cause
Function:
Set the time Low Power/Low Speed must stay detected to activate signal for actions. If detection
disappears before run out of the timer, the timer will be reset.
MG.16.A1.02 - VLT
VLT HVAC Low Harmonic Drive Operating In-
PID Proportional Gain . When no deviation is present, the output
®
is a registered Danfoss trademark
structions
Motor Speed