City Utilities Director Bill Cefalu said the fault caused the 69,000-volt loop breaker — which feeds the substations at Martin Luther King Jr. Avenue and La. 70 — to trip around 9 p.m.
Crews isolated the problem and re-energized the lines at 9:32 p.m.
The two substations feed areas from Roderick Street to Levee Road and from the Lake Palourde area to Sixth Street, Cefalu said.
While it is believed that the fuses to the capacitor bank blew, causing the fault, further investigation is ongoing to determine the cause.