Danfoss VLT HVAC, Инструкция по эксплуатации, Страница: 93 / 156

ence. This is common for pressure-controlled
supply fan and pump applications.
Inverse
[1] causes the adjustable frequency
drive’s output frequency to increase when the
feedback is greater than the setpoint refer-
ence. This is common for temperature-con-
trolled cooling applications, such as cooling
towers.
20-93 PID Proportional Gain
Value:
0.00 = Off - 10.00
0.50
Function:
This parameter adjusts the output of the ad-
justable frequency drive’s PID controller
based on the error between the feedback and
the setpoint reference. Quick PID controller
response is obtained when this value is large.
However, if a value that is too large is used,
the adjustable frequency drive’s output fre-
quency may become unstable.
20-94 PID Integral Time
Value:
0.01 - 10,000.00 = Off s
20.00 s
Function:
Over time, the integrator adds (integrates) the
error between the feedback and the setpoint
reference. This is required to ensure that the
error approaches zero. Quick adjustable fre-
quency drive speed adjustment is obtained
when this value is small. However, if a value
that is too small is used, the adjustable fre-
quency drive’s output frequency may become
unstable.
22-21 Low PowerDetection
Value:
Disabled [0]
Enabled [1]
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!
22-22 Low Speed Detection
Value:
Disabled [0]
Enabled [1]
Function:
Select Enabled for detecting when the motor
operates with a speed as set in par. 4-11 or
4-12,
Motor Low Limit
.
22-23 No-Flow Function
Value:
Off [0]
Sleep Mode [1]
Warning [2]
Alarm [3]
Function:
Common actions for low power detection and
low speed detection (Individual selections not
possible).
Warning: Messages in the local control panel
display (if mounted) and/or signal via a relay
or a digital output.
Alarm: The adjustable frequency drive trips
and the motor stays stopped until reset.
VLT ® HVAC Drive Instruction Manual
6. How to program the adjustable frequency
drive
MG.11.A4.22 - VLT
®
is a registered Danfoss trademark
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