Aspects Regarding Testing of Electromagnetic Contactors Sensitivity to Voltage Dips

The present status regarding the power consumption in electric networks reveals a higher number of events caused by conducted electromagnetic disturbances. The impact of short and repetitive interruptions of electric voltage represents an important issue in the operation of electric and electronic equipments. Tracing the sensitivity characteristics of electromagnetic immunity type CBEMA of electrical equipment to power failure and short duration interruptions is an effective method for estimating the domain of operability and to improve the operational safety of electrical equipments. The assessment of electrical equipment functionality is emphasized in this paper through an experimental research on AC electromagnetic contactors. The study comprises theoretical and experimental research on the low voltage AC contactors as equipment under tests, description of the test stand and the developed procedure for obtaining the CBEMA immunity curves at abrupt and gradual, individual and repetitive voltage dips, with different dip initiation angle values. Some interpretations of the results are given.