Working with motor locked-rotor test data
Locked-rotor testing of three-phase squirrel cage induction motors is used for design validation and quality control; it also can be a valuable diagnostic tool. But, this testing isn’t a common task for most service centers. Two challenges service centers often face are dynamometer torque capacity and test panel electrical capacity. The work-around is usually reduced-voltage testing, which presents another challenge – how to extrapolate the test data to rated voltage with reasonable assurance of accuracy. If the extrapolation is too far off, we run the risk of either rejecting a good motor or accepting a bad one.