will a Permanent Magnet motor be damaged if it tried to run on a V.F.D

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stuckagain

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45 h.p Baldor permanent magnet motor 3 Phase
A standard ABB V.F.D. WAS installed that does not support PM mode.
I understand that they tried to Slowly ramp the motor up
to 1/2 speed for about 40 Seconds
People did not actually see the motor ,located on roof,
run, but the V.F.D. display showed it running at almost 1/2 R.P.M. AND below half full load amps
Did the motor actually run at all,or was the V.F.D. just making calculations?
Did this do damage to the motor or magnets?
 
stuckagain said:
45 h.p Baldor permanent magnet motor 3 Phase
A standard ABB V.F.D. WAS installed that does not support PM mode.
I understand that they tried to Slowly ramp the motor up
to 1/2 speed for about 40 Seconds
People did not actually see the motor ,located on roof,
run, but the V.F.D. display showed it running at almost 1/2 R.P.M. AND below half full load amps
Did the motor actually run at all,or was the V.F.D. just making calculations?
Did this do damage to the motor or magnets?
Click to expand...
Manufacturers say that a special drive is needed but does not specify any damage that can be done
 
stuckagain said:
45 h.p Baldor permanent magnet motor 3 Phase
A standard ABB V.F.D. WAS installed that does not support PM mode.
I understand that they tried to Slowly ramp the motor up
to 1/2 speed for about 40 Seconds
People did not actually see the motor ,located on roof,
run, but the V.F.D. display showed it running at almost 1/2 R.P.M. AND below half full load amps
Did the motor actually run at all,or was the V.F.D. just making calculations?
Did this do damage to the motor or magnets?
Click to expand...

Not likely damaged if it didn't run too long. If the VFD is not designed to run a PMAC motor you will not get good performance, but it's hard for it to damage anything. If the drive, in not seeing a rotor current response (in vector mode for instance), boosts up the flux producing current, it could demagnetize the magnets in the motor. But if the users were unaware that it was a PMAC motor in the first place, then it's highly unlikely they would have gone through the complex process of manually setting up the motor parameters to make it work in vector mode, and if they tried autotune, the drive would have been very confused by the magnets. If it ran for a long time in V/Hz mode, the back EMF from the magnets could have produced damaging voltages on the VFD transistors, but if that had happened, the VFD would be giving you a fault. So like I said, most likely no harm, no foul.
 
That is good news
Fortunately they only bumped the motor for about 30 seconds a couple of times to
verify that the V.F.D. was running
The V.F.D is an ABB model ACH550-01
it does have a Sensorless vector control mode, but I am reading the ABB specs
and it reads "For any standard Squirrel cage motor"
I gather the drive literature must specify Permanent Magnet

Another thing i notice,in general, that Permanent Magnet motors initially start by
turning back and forth a few inches in both directions

Is this due to the Magnets Synchronizing with the Stator?
 
stuckagain said:
That is good news
Fortunately they only bumped the motor for about 30 seconds a couple of times to
verify that the V.F.D. was running
The V.F.D is an ABB model ACH550-01
it does have a Sensorless vector control mode, but I am reading the ABB specs
and it reads "For any standard Squirrel cage motor"
I gather the drive literature must specify Permanent Magnet

Another thing i notice,in general, that Permanent Magnet motors initially start by
turning back and forth a few inches in both directions

Is this due to the Magnets Synchronizing with the Stator?
Click to expand...
FWIW. we make permanent magnet motors mostly for the machine tools industry where high speed and dynamic performance is required.
They produce zero torque at asynchronous speeds. So won't run on a VFD intended for cage motors.
We make our own drives and supply motor and drive as a package.
 
According to ABB
The drive can control the motor
by selecting the Scalar control mode as opposed to the Vector
control mode
 
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