The most frequent concern about high current with a three-phase motor is high no-load current. But the broad issue of high no-load current isn’t the only three-phase motor issue to which plants should pay heed: High current with load and lower-than-expected no-load current are potential areas of concern, too. Let’s explore the sources of all of these.
High no-load current: Motor not rewound
One situation in which higher-than-expected no-load current can occur is with reconditioned motors. Although some motors with no-load currents above or below the guidelines shown in Table 1 may still be satisfactory, motors with no-load current outside of these ranges warrant further analysis.