All most all new locos have static conductor for driver safety and crew safety
Bt old didn't have so They fit and written like this.if this was not fitted in loco lp or alp hair rise up or ear damage occur during running.so to free electrons conductor is used.i think this is it
The...
more... first Static converter was used in WCAM – 3 locomotives jointly developed by RDSO and BHEL in 1997. The Static Converter converters the DC / AC voltage into 3 phase 415 volts for running auxillary machine.