Dr. Penrose,

as you mentioned in the topic "Rotor Fault Asynchronos Servomotor" posted by BRENDA you are the "father" of the RGS (Rotor Grading System)used by ATP on behalf the EMCAT software.

Based on the values given <5 "GOOD Rotor", >5 and <15 "CAUTION" and >15 "SEVERE Rotor fault" I can not recall any rotor test giving me values <15 !!! no matter how acurate the rotor movement was performed.

I recall a 500 HP Extruder motor I first measured ESA in February 2007 "pass" with rotor value C:1. This motor is on a 6 month interval. September 2007 I measurements (several) C:7.
I conducted a MCA Rotor Test RGS value 26.

I attach the two EJr files as well as the RGS print. What possibly could have caused this severe change ? (actually I lost faith in the RGS measurements and inclined to try PdMA's RIC)

An other RGS measurments I perfomed on one of my air compresors. I could not perfom an ESA as the termal protection was triggered after 15 sec. I went to our rewind shop who could not find anything wrong with this motor. I conducted a RGS Inductance test with the RGS value 49. Also the curve looks much better than the one from the example above (see my report in the attachment).

Looking forward to any comments.

This message has been edited. Last edited by: MOGLI,

REPORTE_MCA_Rotor_Test_BDF.pdf (287 Kb, 35 downloads)

Mogli

If you post your inductance numbers (or as an attachment) of one of those motors, I will run it through the original EMCAT RGS program and post the results when I post the other analysis on the other string this evening. I am curious why, on the other string, the motors that I saw had such high numbers, anyways. For instance, even with all 36 readings you should not be able to add the scores up to 76.

I am attaching an example from the original EMCAT version 1.3 software. In this example, the score was 50.5 (28 points) because of rotor eccentricity and a severe casting void (the impact of the valley of the waveform on the far right).

Howard

RGS_image.pdf (158 Kb, 16 downloads)

Dr. Penrose,

the inductance numbers you see on the attachment are the real ones obtained by the ATP IV.

Furthermore I sent you to the mail address "howard@motordoc.com" the EJr files and the two RGS files for the compresor and the extrudor.

The document attached to your answer looks familiar and as far as I can recall it is from the EMCAT2003.

Looking forward to your response

MOGLI

Rotor_Tests_Extrudor_DM61.pdf (37 Kb, 17 downloads)

MOGLI

Here is the data from the older version of the EMCAT and the results from the online tester.

The RIC test will not provide any answer or value. There is always some level of data interpretation required for any test, just as with vibration analysis, etc. The training I perform covers all of the technologies including ATPro, PdMA, Baker, Iris and the MCSA data taken with vibration equipment. As far as your first comment goes, I have no relationship with ATPro (left them three years ago), I just help my clients work with whichever system they use.

I have no doubt that the inductance readings are correct. My comment had to do with how the ATPro new software must be handling the data for the RGS, which is obviously different than the original method I had developed and installed in the original EMCAT software (up to version 1.3). Inductance is inductance regardless of which instrument you use.

I also noticed on your reports that you are using the impedance unbalance for energy costs. It appears as if this was done with the rotor in one position. The only way this method works is if you are using the 'rotor compensated' method with the ATIV/AT31.

Sincerely,
Howard

Mogli_2.pdf (1,188 Kb, 20 downloads)