Testing Motor Operation; Parking; Automatic Motor Adaptation (Ama); Introduction - Danfoss VLT FC 280 Operating Manual

VLT® Midi Drive FC 280
Operating Guide
7.
Parameter 1-40 Back EMF at 1000 RPM.
Enter line-to-line back EMF of the PM motor at 1000 RPM mechanical speed (RMS value). Back EMF is the voltage gener-
ated by a PM motor when no drive 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.

5.4.2.3 Testing Motor Operation

Procedure
1. Start the motor at low speed (100–200 RPM). If the motor does not run, check installation, general programming, and mo-
tor data.

5.4.2.4 Parking

This function is the recommended option for applications where the motor is rotating at low 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
applications are shown in Table
Table 18: Recommendations in Different Applications
Application
Low inertia applications I
Load
<5
(1)
tor
Medium inertia applications
50>I /I >5
Load Motor
High inertia applications I
Load
> 50
High load at low speed <30% (rated
speed)
I =The inertia of load. I
1
Load Motor
If the motor starts oscillating at a certain speed, increase parameter 1-14 Damping Gain. Increase the value in small steps.
Adjust the starting torque in parameter 1-66 Min. Current at Low Speed. 100% provides nominal torque as starting torque.

5.4.3 Automatic Motor Adaptation (AMA)

5.4.3.1 Introduction

It is highly recommended to run AMA because it measures the electrical characteristics of the motor to optimize compatibility be-
tween the drive and the motor in VVC
• The drive builds a mathematical model of the motor for regulating output motor current, thus enhancing motor performance.
•
Some motors are 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 List of Warnings and Alarms.
• Run this procedure on a cold motor for best results.
48 | Danfoss A/S © 2022.02
18.
Settings
/I
Mo-
• Increase the value for parameter 1-17 Voltage filter time const. by factor 5 to 10.
•
Reduce the value for parameter 1-14 Damping Gain.
•
Reduce the value (<100%) for parameter 1-66 Min. Current at Low Speed.
Keep calculated values.
/I
Increase the values for parameter 1-14 Damping Gain, parameter 1-15 Low Speed Filter Time
Motor
Const., and parameter 1-16 High Speed Filter Time Const.
Increase the value for parameter 1-17 Voltage filter time const. Increase the value for param-
eter 1-66 Min. Current at Low Speed (>100% for longer time can overheat the motor).
=The inertia of motor.
+
mode.
+
PM settings. Recommendations in different
AQ381425076031en-000101 / 130R1223
Commissioning