Oahu Community Correctional Center — the state’s largest prison facility — had been running on generators since a power outage on Friday, but finally had full electrical power restored Monday night.

Th cause of the power outage remains under investigation.

The 1,162 inmates at the overcrowded prison were without air conditioning for the entire weekend because generators used to provide backup power were not connected to the cell blocks and other prison areas until Monday.

The Department of Public Safety said full power was restored at the aging 41-year-old prison facility at 10 p.m. The Kalihi prison, which is only supposed to house 954 inmates, currently houses 1,162 inmates.

A generator is still being used to power the air conditioning for the entire facility.

The Department of Public Safety said the air conditioning will remain on the generator until a faulty transformer can be replaced. The part has been ordered.

All prison cells were secured during the power outage.

One of the problems created by the outage was that the arraignments Monday of inmates awaiting trial normally done using the prison’s video system connected to Circuit Court had to be postponed until Thursday.

An extra generator was brought in Monday night to power the air conditioning.

During the day the staff allowed inmates to have longer recreational periods in the outside recreation yard.

“The heat was uncomfortable not only for inmates, but for the men and women who work at the jail. They did their jobs, promoting the safety and wellbeing of their fellow officers and staff, as well as the inmates, in less than ideal conditions, and I commend them for doing an excellent job,” said Public Safety Director Nolan Espinda.

Noting the age of the prison, Nolan said: “These kinds of problems will continue to happen until we can replace it with a modern, efficient building. We hope to continue working with the legislature and the community to redevelop OCCC as soon as possible.”

During the past legislative session, Gov. David Ige sought $489.3 million to move OCCC, merge it with the Halawa Correctional Facility and revitalize the Kalihi area with transit-oriented development. But lawmakers only approved $60 million for design of a new prison facility.