Stator Coatings and VFD Drives 1

[Lovison]

Bakes and Dips I read about all the time. This covers the stator windings. But I've seen different coatings from time to time and I wonder if you have a motor that is rated for a VFD if the winding coating process is different?

I would assume (and I hate that word) that all VFD motors would have variable heating occurrence of the windings due to the variable voltages and amp draws that would take place over the range its operating (is this correct?)

Example: A submersible motor (TENV)not a TEFC or ODP type. I suspect it would be more susceptable to condensate issues as well as the temperature variances because of it being a non-ventilating motor and that it would require a different winding coating arrangement?

I know OEM's make that decision but is it based on the issues I mentioned above or what?

Any help out there?

Thanks Guys Wayne E. Lovison
service-parts@naglepumps.com

 

[jbartos]

Suggestion: There may be the capacitive property of the winding insulating layer taken into consideration. The inverter motors are built to withstand the higher harmonic content that implies higher frequencies. Normally, capacitance is proportionally dependent on the relative permittivity. The smaller capacitance needs smaller permittivity. This in turn will increase the capacitive reactance, Xc=1/(2pifC), where C proportional to the relative permittivity of insulation layer. Therefore, the insulation layer impedance is increased providing the better insulation.