Measurement of 2300 volt motor defects with on-line diagnostic techniques

Electromagnetic Interference (EMI) analysis of the Radio Frequency (RF) spectrum produced by defects in large rotating electrical machines has been applied in the utility industry for almost 20 years. Motors rated 4 kV were first successfully evaluated in the petrochemical environment in 1990. Application of EMI techniques to determine the in-service condition of 2300 voltage motors has recently been implemented at industrial and utility sites. Many of the defect signatures observed with machines operating at 4 kV and higher were also found to be present at 2300 volts. Data from several machines is presented along with the conditions indicated