Danfoss VLT Midi Drive FC 280 Operating Instructions Manual page 31

Commissioning
Enter line to common direct axis inductance of
the PM motor.
If only line-line data is available, divide the line-
line value with 2 to achieve the line-common
(starpoint) value.
It is also possible to measure the value with an
inductance meter, which also takes the
inductance of the cable into account. Divide the
measured value by 2 and enter the result.
7. Parameter 1-40 Back EMF at 1000 RPM.
Enter line-to-line back EMF of PM motor at 1000
RPM mechanical speed (RMS value). Back EMF is
the voltage generated by a PM motor when no
frequency converter is connected and the shaft is
turned externally. Back EMF is normally specified
for nominal motor speed or for 1000 RPM
measured between 2 lines. If the value is not
available for a motor speed of 1000 RPM,
calculate the correct value as follows: For
example, if back EMF at 1800 RPM is 320 V, the
back EMF at 1000 RPM is:
Back EMF=(Voltage/
RPM)x1000=(320/1800)x1000=178.
Program this value for parameter 1-40 Back EMF at
1000 RPM.
Test motor operation
1. Start the motor at low speed (100–200 RPM). If
the motor does not turn, check installation,
general programming and motor data.
Parking
This function is the recommended choice for applications
where the motor is rotating at slow speed (for example,
windmilling in fan applications). Parameter 2-06 Parking
Current and parameter 2-07 Parking Time are adjustable.
Increase the factory setting of these parameters for
applications with high inertia.
Start the motor at nominal speed. If the application does
+
not run well, check the VVC
recommendations in different applications.
MG07A102
Operating Instructions
PM settings. Table 5.13 shows
Danfoss A/S © 11/2015 All rights reserved.
Application Settings
•
Low inertia applications Increase the value for
I /I <5 parameter 1-17 Voltage filter time
Load Motor
const. by factor 5–10.
•
Reduce the value for
parameter 1-14 Damping Gain.
•
Reduce the value (<100%) for
parameter 1-66 Min. Current at
Low Speed.
Medium inertia Keep calculated values.
applications
50>I /I >5
Load Motor
High inertia applications Increase the values for
I /I > 50 parameter 1-14 Damping Gain,
Load Motor
parameter 1-15 Low Speed Filter Time
Const., and parameter 1-16 High
Speed Filter Time Const.
High load at low speed Increase the value for
<30% (rated speed) parameter 1-17 Voltage filter time
const.
Increase the value for
parameter 1-66 Min. Current at Low
Speed (>100% for longer time can
overheat the motor).
Table 5.13 Recommendations in Different Applications
If the motor starts oscillating at a certain speed, increase
parameter 1-14 Damping Gain. Increase the value in small
steps.
Starting torque can be adjusted in parameter 1-66 Min.
Current at Low Speed. 100% provides nominal torque as
starting torque.
5.4.3 Automatic Motor Adaptation (AMA)
Automatic motor adaptation (AMA)
It is highly recommended to run AMA, because it measures
the electrical characteristics of the motor to optimize
compatibility between the frequency converter and the
motor under VVC + mode.
•
The frequency converter builds a mathematical
model of the motor for regulating output motor
current, thus enhancing motor performance.
•
Some motors may be unable to run the complete
version of the test. In that case, select [2] Enable
reduced AMA in parameter 1-29 Automatic Motor
Adaption (AMA).
•
If warnings or alarms occur, see chapter 8.4 List of
Warnings and Alarms.
•
Run this procedure on a cold motor for best
results.
5 5
29