Prerequisites
- Connect a current clamp to the volts input on the analyzer.
- Place the current clamp around one wire of the three-phase power source.
- Enter the correct sensitivity for the clamp, and account for a current transformer (CT) ratio if you measure on a secondary wire.
Overview
Rotor Bar Test Motor Current finds rotor bar defects in AC motors. The motor should be at least 50 percent loaded. Sidebands around electrical line frequency, spaced at the number of poles times the motor’s slip frequency, indicate a rotor bar defect. If the difference between the sideband amplitudes and the line frequency amplitude is less than 60 dB, suspect rotor bar problems.