Two trips on the electrical system briefly left tens of thousands of customers without power Monday evening, Newfoundland and Labrador Hydro says.

“The first involved a trip of a transmission line near Stephenville and the Maritime Link, which affected Newfoundland Power customers in the Stephenville area,” the company said in a statement. “All customers were restored within 55 minutes.

“The second occurred while bringing the Maritime Link back into service. The Maritime Link tripped resulting in Stephenville customers to again lose power. During this event, both poles of the Labrador Island Link had been delivering around 450 MW. While LIL did not trip, power flow decreased from 450 MW down to 175 MW. This caused a brief outage to some customers across the island. LIL was quickly brought back up to 422 MW. Newfoundland Power has informed us that approximately 31K customers were impacted during this event. All customers were restored within 15 minutes. Our investigation into the event is ongoing.”

Hydro says these trips are designed to protect the system from further equipment issues, but in the process, customers may be disconnected from the electricity grid for a brief time, usually less than 30 minutes.

An unplanned outage affecting customers on Fogo Island is unrelated to these events.