Specialized articles
Analysis of Induction Electric Motors
In recent years, technologies have been developed that enable the [...]
In recent years, technologies have been developed that enable the diagnosis of AC motors by simultaneously measuring current and voltage.
Vibration analyses can be supplemented with current and supply voltage analyses when diagnosing electric induction motors.
The measured parameters are:
- Power Supply.
- Line voltage.
- Vibration.
The technology that Preditec/IRM offers for the optimal application of these techniques is the Predimotor, available in both offline and online versions.
Failure Modes
Vibrations in electrical machines can have a mechanical or electrical cause. The symptoms used to diagnose electrical faults can be found in the vibration spectra or in the dynamic current or voltage signal of the motor in each phase. Electrical problems detectable using vibration, current, and voltage analysis techniques can be classified into six failure modes:
- Power quality issues, detectable via a power test.
- Faults in the power circuit, detectable through standard tests and the power test.
- Insulation defects, detectable by the standard test, the polarization index, and the step-voltage test.
- Stator faults, detectable by the standard test, rotor influence, the power test, and the start-up test.
- Rotor failures, detectable through vibration analysis, standard testing, rotor influence testing, rotor evaluation, and start-up testing.
- Air gap defects, detectable by vibration analysis, standard test, rotor influence, and eccentricity test.
We recommend reading the PdMA article “Failure Zone Analysis” and watching the following videos on fault detection in:
Useful links:
- Return on Investment Analysis
- Course on Troubleshooting Induction Motors
- Predimotor Offline
- Predimotor Online
Contact one of our engineers specializing in predictive maintenance for advice at: info@preditec.com
