Bearings of motors powered through VFD
Bearings of motors powered through VFD
(OP)
On site we have 3 400V motors 200kW , spupplied via ABB ACS 800 inverters. he motor bearings are nit special insulated bearings , for applications that use inverters, they are typical nearings. The frame of the motor and the driven fan are grounded, the motor cbles are special shielded power cables. Is it possible for us to change the bearings with other tyoes, special insualted?





RE: Bearings of motors powered through VFD
not quite sure what you ask.
Do you have standard (not insulated) bearings and want to put in insulated (Insocoat) bearings?
That would usually not be a problem (except that Insocoat may run a little hotter if coating is on outer rim).
Why do you want to change bearing types?
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Bearings of motors powered through VFD
RE: Bearings of motors powered through VFD
RE: Bearings of motors powered through VFD
Do you have a problem with your bearings or do you think you might have a problem with your bearings?
If you have a problem then first be sure it is related to the inverter before going further otherwise its an expensive process and you may be back to square one. The type of bearing failure is quite specific if it is.
RE: Bearings of motors powered through VFD
If the motors are running fine then you don´t have nothing to alarm. But I think the best you can before take some action about the bearings is to do a question for your motor´s dealer or to the manufacturer about the motor´s design.
Normally you could find two typical designs for inverter´s motors, one with insulated or hibrids bearings and other with standard bearings and OD shaft insulated, I think the last could be your case.
Regards
Carlos
RE: Bearings of motors powered through VFD
RE: Bearings of motors powered through VFD
that's quite a major undertaking on 3 x 200kW just to see if there is a problem!
There is a device coming onto or already on the market called BEPPE Bearing predictor developed by one of Eng-Tips regular tipsters Skogsgurra. Try http:
At the moment there is nothing really on the market to predict if EDM is causing premature bearing failure other than setting up an oscilliscope and knowing what to look for.
BTW, I have no commercial interest in BEPPE. I wish I did as it is a great little device!