A Switching Surge Transient Recording Device

A switching surge transient recording device has been designed, built, and tested which serves as a continuous, unattended monitor of power system switching transients. Rather than reproduce the transient waveform, the recorder senses and records the positive and negative peak magnitudes of the transient to within a 4.0 per unit overvoltage limit, the maximum positive and maximum negative rates of rise of voltage within the limits of 20 to 2000 μS front time, and the instantaneous voltage level at the time of transient occurrence. The basic operation of the recorder is described and a portion of the data obtained during laboratory and field tests is presented.