Motor current signature analysis (MCSA) has proven to be a highly valuable predictive maintenance tool. Although it is a relatively young, rarely utilized technology, it is rapidly gaining acceptance in industry today. Mechanical faults related to belts, couplers, alignment and more are easily found through the use of a demodulated current spectrum. MCSA is simply the process by which motor current readings are recorded and analyzed in the frequency domain. It has been around since 1985 and proven itself well over the years in locating rotor faults and air gap problems in motors.