VFD motor insulation
VFD motor insulation
(OP)
The VFD(inverter) normally creates harmonics during operation. Motor manufacturer states that the insulation class of VFD driven motor should be higher than DOL driven motor in order to avoid deteriation of insulation because of harmonics. Is that true ? What is normal standard in aspect of winding of motor .





RE: VFD motor insulation
http://www.rema.uk.com/pdfs/vsd1.pdf
But, it isn't the harmonics that create the problems. Harmonics are low frequency components - from 100 Hz to 2+ kHz and are a matter between mains and inverter. Not the motor.
What kills motor insulation is the HF contents of the motor voltage and the associated ringing that the PWM voltages create.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: VFD motor insulation
Do not trust such statements as "Inverter Duty", "Inverter Rated", or "Inverter Ready". These are marketing terms with no technical specification to back them up.
If you are elsewhere in the world, there may be similar IEC specs around but I do not know what they are.
RE: VFD motor insulation
Bill
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"Why not the best?"
Jimmy Carter
RE: VFD motor insulation
If take a soft starter, then is motor insulation higher than as well ?
RE: VFD motor insulation
Using a filter between the motor and the VFD can greatly reduce the voltage spikes seen in the motor. But they aren't cheap. Still it may be a solution for you.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com