Instrumentation Techniques in High Voltage Substations - Part I Measuring, Triggering and Interference Reduction

Measurement of transient potentials in substation yards on control circuits, CTs, CPTs, 115 vac receptacles, howlers, yard telephones, heaters, flood lights and cable lead sheaths during disconnect switch arcing require more stringent instrumentation techniques than comparable measurements made in the control house. Methods and equipment have been devised to trigger oscilloscopes independent of recorded transient and reduce measuring circuit interference voltages.