Automatic Motor Adaptation (Ama) - Danfoss FC 300 Design Manual

FC 300 Design Guide

Automatic Motor Adaptation (AMA)

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AMA is an algorithm to measure the electrical motor parameters on a motor at standstill.
This means that AMA itself does not supply any torque.
AMA is useful when commissioning systems and optimizing the adjustment of the adjustable
frequency drive to the applied motor. This feature is particularly used where the default
setting does not apply to the connected motor.
Par. 1-29 allows a choice of complete AMA with determination of all electrical motor parameters
or reduced AMA with determination of the stator resistance Rs only.
The duration of a total AMA varies from a few minutes on small motors to more than 15 minutes on large motors.
Limitations and preconditions:
For the AMA to determine the motor parameters optimally, enter the correct motor
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nameplate data in par. 1-20 to 1-26.
For the best adjustment of the adjustable frequency drive, carry out an AMA on a cold
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motor. Repeated AMA runs may lead to a heating of the motor, which results in an increase
of the stator resistance, Rs. Normally, this is not critical.
• An AMA can only be carried out if the rated motor current is minimum 35% of the rated output current of
the adjustable frequency drive. An AMA can be carried out on up to one oversize motor.
It is possible to carry out a reduced AMA test with an LC filter installed. Avoid carrying out
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a complete AMA with an LC filter. If an overall setting is required, remove the LC filter while
running a total AMA. After completion of the AMA, reinsert the LC filter.
If motors are coupled in parallel, use only a reduced AMA if any.
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Avoid running a complete AMA when using synchronous motors. If synchronous motors
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are applied, run a reduced AMA and manually set the extended motor data. The AMA
function does not apply to permanent magnet motors.
The adjustable frequency drive does not produce motor torque during an AMA. During an AMA, it is
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imperative that the application does not force the motor shaft to run, which is known to happen,
e.g., with windmilling in ventilation systems. This disturbs the AMA function.
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Application Examples
MG.33.B6.22 - VLT is a registered Danfoss trademark