The Lansing Board of Water & Light says the outage occurred when a portion of the Eckert substation tripped offline during required testing. The 90-minute outage ended shortly before 11:30 a.m. Tuesday.
The utility says future testing will occur on nights and weekends "to minimize any inconvenience if outages result from the testing."
The Lansing State Journal reports (http://on.lsj.com/2nZoUmP ) the Eckert substation caused at least two widespread power outages last year.
Utility spokesman Steve Serkaian says it initially reported 30,000 customers lost power because that's how many are served by the substation. Officials later discovered only a portion of those people were affected.