Newfoundland and Labrador Hydro says a lubricating oil pump that didn't work properly is the cause of serious damage to a generating unit at Holyrood in January.

The unit has been out of operation ever since.

High winds, heavy snow, and salt contamination led to electrical problems that caused two units to shut down.

One did so without incident. 

But the lack of lubricating oil caused the other unit to vibrate, resulting in serious damage.

Hydro vice-president Rob Henderson says the problem has been identified and fixed.

"We've done a thorough repair on that unit, so it's in very good shape now for meeting this coming winter load," Henderson said Thursday.

"So with the Holyrood plant, we're in good shape now for this winter."

The cost of repairs is actually less than first expected.

It's now estimated to come in at $10 million, or $3 million less than initial projections.

The unit should be back in operation later this month.