Induction motor rotor testing parameter

Induction motors rotor are usually Aluminium casted. The performance i.e. quality of electrical induction motors is depending on the quality of the rotor built into the motor. Thus quality assurance of this important component is more and more becoming to be a major issue. For critical applications such as hermetic compressors, pumps etc. continuous quality monitoring of the rotor has been applied for many years and has proven to be the key for superior product quality.

To ensure quality following parameters need to check from R&D point of view. 

1. Broken or interrupted rotor bars. 
2.  Cold soldered or missing connection between bar and end ring. 
3.  Porosity either in the end rings or the rotor bars due to faulty injection processes, inferior aluminum alloy quality, and/or gaseous contamination. 
4.  Insufficient oxidation between aluminum rotor bar and steel core resulting in the phenomenon known as soldering. 
5.  Deviation of the rotor bar angle (skew). 
6.  A short circuit between two or more rotor bars (fining). 
7.  Eccentricity problems. 
8.  Material inconsistencies in the aluminum alloy. 
9.  Material inconsistencies in the steel core. 

For continuous production quality monitoring following quality checking is mandatory- 

1. Broken or interrupted rotor bars. 
2.  Cold soldered or missing connection between bar and end ring. 
3.  Porosity either in the end rings or the rotor bars due to faulty 

Rotor Porosity Testing article

Rotor quality checking is not a mistery