Taking the Mystery Out of Electric Motors: Rotor Analysis and Troubleshooting

Squirrel Cage Rotor troubleshooting has come a long way in the last decade. We now have six different methods to track and identify rotor defects.

1. Pole Pass Frequency (Fp) Sideband amplitude around Line Frequency
2. Fp Sidebands at the 5^th Harmonic of Line Frequency (NA for 2-pole motors)
3. Fp Amplitude in Current Demodulation
4. Start-Up Duration from the In-Rush/Start-Up Test
5. Waveform Analysis from the Rotor Influence Check (RIC)
6. Winding Inductance Trending

Before you make a call or before you call PdMA Technical Support collect some correlative data to assist in the confident assessment of your rotor. To see a detailed discussion about Rotor Analysis and Troubleshooting view Rotor Tips – Todd and Noah Podcast.