Analysis of induction electric motors
In recent years, technologies have been developed that, by means of [...]
In recent years, technologies have been developed that allow the diagnosis of AC motors by means of simultaneous current and voltage measurement.
Vibration analysis can be complemented with current and supply voltage analysis when diagnosing induction electric motors.
The parameters measured are:
- Power supply current.
- Line voltage.
- Vibration.
The technology that Preditec/IRM proposes for the optimal application of these techniques is Predimotor, both in its offline and online versions.
Failure modes
Vibrations in electrical machines can have a mechanical or electrical origin. Symptoms for diagnosing faults of electrical origin can be found in the vibration spectra or in the dynamic current or voltage signal of the motor in each phase. Problems of electrical origin detectable with vibration, current and voltage analysis techniques can be classified into six fault zones:
- Power quality problems, detectable by power test.
- Power circuit faults, detectable by standard tests and power test.
- Insulation defects, detectable by standard test, polarization index and step voltage test.
- Stator faults, detectable by standard test, rotor influence, power test and start-up test.
- Rotor failures, detectable by vibration analysis, standard test, rotor influence test, rotor evaluation and start-up test.
- Air gap defects, detectable by vibration analysis, standard test, rotor influence and eccentricity test.
It is recommended to read the PdMA article "Fault Zone Analysis" and the following videos that discuss fault detection in:
Links of interest:
Contact one of our specialist predictive maintenance engineers for advice on: info@preditec.com
