
180 Introduction to Electrical Power and Power Electronics
dark. If phase C on the primary side gets grounded, phase C of the secondary side
also loses the voltage, and the phasor sum of the remaining two voltages in the Δ is
not zero. This results in lamp L being lit, indicating a ground fault in one of the lines,
although it cannot indicate which line is faulted. Locating the fault in any of these
schemes requires troubleshooting skills mixed with good logic.
7.4 DISTRIBUTION FEEDER VOLTAGE DROP
The distribution system has an automatic voltage regulation scheme at one or more
control stations, such as the factory switchboard or township substation, ...