Rotor Winding Monitoring – Induction Motors

Current signature analysis motoring detects rotor cage winding faults in induction motors including broken rotor bars, cracked shorting rings and unequal air gaps.

Condition Based Monitoring - Current Signature Analysis

The most common causes of induction motor failures are due to breaks in rotor bars or shorted circuit rings due to rotor eccentricity.  Current Signature Analysis (CSA) is used to accurately measure faults in the induction motor rotors through changes in the rotor magnetic field.

Current Signature Analysis is important in tool in preventing:

It is based on the general principle that any disturbance that the motor is subjected to will manifest itself as an electrical signal in the stator current. For example, a broken rotor bar will result in a counter-rotational magnetic field, which will be reflected in the stator current.

Current Signature Analysis determined from the spectrum of the signals embedded in the stator current, and by understanding induction motor and load dynamics it is possible to determine the nature of rotor problems. It uses the fact that broken rotor bars will provide a tell-tale signature in the frequency spectrum with spectral lines at harmonics of twice the slip frequency above and below the 50 Hz or 60 Hz fundamental frequency.  This is usually 1-2Hz on either side of the fundamental frequency (depending on the slip).  As soon as the amplitude exceeds a certain empirically determined threshold (relative to the amplitude of the fundamental), it indicates a failure condition may be likely.

Contact Us To Discuss

Rotor Winding Monitoring – Induction Motors Products


Online Instruments For Periodic Monitoring

Have a Question?

Looking for more information or need a quote? Please fill out the contact form below and we will get back to you shortly.

Rotor Winding Monitoring – Induction Motors Resources


Articles, Technical Papers, & Case Studies

Looking for more Information

Sign up to receive our latest whitepapers, webinars, new product information, product updates and more.