More test results:
We used it on some cooling tower motors to see if the device could detect the EDM events. The device did not show anything on one motor and show some signs on another motor. It did work well with a lead from a grounding brush when the lead is not connected to the frame or...
Thanks very much for the valuable information! With the key word "high frequency motors" I was able to find many manufacturers although most of them were machine spindle manufacturers for milling or grinding and CNC routers.
I will contact them to discuss the application.
One curious...
Hello, I am looking for a motor manufacturer who sells about a 20,000 rpm, 20HP,inverter duty motor. It can be designed but the cost is an issue. Any clues will be appreciated. I am also curious if I can run any inverter duty motor at 20,000 rpm once I replace the bearings and balance the rotor?
Hello,
I tested SKF bearing erosion device on a VFD motor. If the rotor is not attached to anything, the device does not show anything. If the shaft is attached to somthing, then it shows the numbers on the screen of the device. I believe that the device is simply measuring the high frequency...
Hello, Petronila,
Please read the IEEE paper published by Dr. Muetze. " A. Muetze, A. Binder, “Calculation of Circulating Bearing Currents in Machines of Inverter-Based Drive Systems,”IAS2004, pp. 720 – 726, 2004" . This paper was republished (with different title and some changes) on IEEE...
EWEE,
What kind of motor drive do you use for the application? If the drive is VFD, you may be dealing with the electrical bearing damage. Have you cut the bearing and check the bearing races?
I recently examined the bearing races in motors run by a variable frequency drive. The motors ran about 8 months at 1800 rpm. When I opened up the bearing, a big ring of frosting was visible. I took SEM picture of the frosted area and observed thousands of "pits and pot holes" caused by...