70 Series Event Recorders Capture What Electromechanical Relays Cannot

PUBLISHED ON Jun 23, 2009

These two 70 Series event records show a voltage collapse on A and B phase lasting about five cycles.
The waveform record shows an oscillograph of the instantaneous sinusoidal voltage values similar to those you would see on an oscilloscope. The disturbance record shows the measured voltage values for the same condition you might read on an ammeter, if it were possible for an ammeter to respond that quickly.
In addition to event recording features, the 70 Series IEDs also provide distance-to-fault, historical trends, and real-time measurements to SCADA.