Measurement of transient voltages on class 313 EMU during service running October 1978 (TM-ETR-116)

Experiments have recently been carried out to measure the level of surges generated during operation of rolling stock circuit breakers (1,2). These have been initiated because of reports of high voltage surges being generated by vacuum circuit breakers (VCB) particularly when breaking ("chopping") low currents, such as transformer magnetising currents.