Our last two MCA data analysis tips stated that it is not uncommon for new users that begin a MCA motor testing program can have between 10-30% of motor systems tested to exhibit some alarm condition. Tip 2 discussed the importance of performing additional testing to confirm the source of the alarm. I.e. is it related to connections, cables, or motor windings?
Moreover, with respect to AC induction squirrel-cage rotor motors <1000V, many new motors will exhibit an inductance and impedance imbalance, due to motor design/construction. Therefore, a healthy motor can exhibit an impedance and inductance alarm (even though it is in good condition). MCA measurements include impedance and inductance measurements, but phase balance is not used for assessing the condition of the motor windings.