Assessment of Efficiency for Refurbished 3⌽ Squirrel Cage Induction Motor using No-load Field Data

Three phase Squirrel Cage Induction Motors (SCIM) are widely used as industrial drives due to their self-starting, reliable and economical feature. The estimation of the refurbished/rewound SCIM’s working efficiency is given priority in this work. The conventional test set up used by manufacturing industry may not be feasible solution for estimating the efficiency of refurbished/rewound SCIM due to transportation and other issues. Current Vector Method (CVM) and Modified IEEE Standard 112 Equivalent Circuit Method (Modified IEEE Std. ECM) are used based no-load availability of the data. The measured stray load losses are accounted in estimating the efficiency. Hence, the expensive dynamometer test procedure is removed. The proposed methods are simple, more accurate and less expensive which will give minimum possible error. Efficiency estimation using different methods are being calculated, verified and compared for three different rating of three phase SCIM. Mainly focused on the 110kW SCIM carried out in this research work.