Fault voltage drop and impedance at short-circuit currents in low-voltage circuits

In the paper are presented new data on (1) arc-voltage drop and current-limiting effects for arc faults in bar-conductor structures, (2) current-limiting effect of insulated-cable arc faults, (3) cable impedance in an iron conduit, and (4) impedance of low-voltage switchgear circuit assemblies, derived from tests at short-circuit currents in circuits with open-circuit line-to-line voltages of 208–600 volts at 60 cycles. The currents ranged from less than 10,000 amperes to values as high as 100,000 amperes rms in some cases.