Power outage caused by Ft. Assinniboine substation

The power outage that took out the power across the Hi-Line from Chester to Glasgow was caused by a problem in the Fort Assinniboine substation.

NorthWestern Energy spokesperson Claudia Rapkoch said the outage was caused by a security measure that shuts the system down if it detects a problem. The safety feature detected a problem in one of the lines to the Fort Assinniboine substation and kicked in.

“When that system senses a problem, for whatever reason, it will isolate the problem by essentially shutting itself off,” Rapkoch said.

This safety measure is to allow operators to come in and mak...